COLEMAN, Circuit Judge:
This is an appeal from a jury verdict and judgment for the defendant in the second trial of a suit on implied warranty, grounded on a prior jury finding in the same case that plaintiff’s decedent died of cancer and that smoking cigarettes was a cause thereof. For the second time, we reverse and remand for a new trial.
Nearly ten years ago, in December, 1957, Edwin Green, Sr. brought suit against the American Tobacco Company, claiming that he had incurred lung cancer as a result of smoking the defendant’s product, Lucky Strike cigarettes.
About two months after filing the suit, on February 25, 1958, Mr. Green died. His administrator was substituted as plaintiff and his widow also filed suit under the Florida Wrongful Death Statute. On two theories of liability, breach of implied warranty and negligence, the cases after consolidation were tried to a jury, which returned general verdicts for the defendant. In answer, however, to certain interrogatories submitted under Rule 49(b), Federal Rules of Civil Procedure, 28 U.S.C.A., the jury in this first trial found that Mr. Green had primary cancer of the lung, that this was the cause or one of the causes of his death, and that smoking Lucky Strike cigarettes was a proximate cause or one of the proximate causes of the cancer. Notwithstanding this finding, the verdict went to the defendant because, in response to another interrogatory, the jury further found that on or prior to February 1, 1956, the defendant Tobacco Company by the reasonable application of human skill and foresight could not have known that users of Lucky Strike cigarettes, such as Mr. Green, would thereby be put in danger of contracting lung cancer.
Of course, the plaintiffs appealed. On May 2, 1962, 5 Cir., 304 F.2d 70, a panel of this Court composed of Judges Rives, Cameron, and Griffin Bell1 affirmed the judgment in favor of the cigarette manufacturer. In that opinion the result turned on the jury finding that there was no developed human skill or foresight which could have afforded the manufacturer a knowledge of the harmful effects. Judge Cameron dissented, quite cogently pointing out that even for breach of implied warranty the decision amounted to a holding that the exercise of reasonable care on the part of the Tobacco Company would exonerate it from liability.
On petition for rehearing, decided June 20, 1962, 304 F.2d at page 85, rehearing was granted to the extent of certifying to the Supreme Court of Florida2 the following question:
“Does the law of Florida impose on a manufacturer and distributor of cigarettes absolute liability, as for breach of implied warranty, for death caused by using such cigarettes from 1924 or 1925 until February 1, 1956, the cancer having developed prior to February 1, 1956 and the death occurring February 25, 1958, when the defendant manufacturer and distributor could not on, or prior to, February 1, 1956, by the reasonable application of human skill and foresight, have known that users of such cigarettes would be endangered by the inhalation of the main [100]*100stream smoke from such cigarettes of contracting cancer of the lung?” [154 S.2d at 170].
It is to be noted that the question begins “Does the law of Florida impose on a manufacturer and distributor of cigarettes absolute liability, as for breach of implied warranty [?]”. It was nearly a year before the Supreme Court of Florida responded in a 5-2 decision [154 So.2d 169, June 5, 1963]. The Court concluded:
“That the question thus framed does not present for our consideration the issue of whether the cigarettes which caused a cancer in this particular instance were as a matter of law unmerchantable in Florida under the stated conditions, nor does it request a statement of the scope of warranty implied in the circumstance of this case. The inquiry before us is, instead, limited to the status of Florida law upon imposition of liability ‘as for breach of implied warranty’ when the manufacturer or warrantor ‘could not by the reasonable application of human skill and foresight, have known of the danger’.” [emphasis ours]
The Florida Supreme Court proceeded to state in clear and unmistakable language:
“That a manufacturer’s or seller’s actual knowledge or opportunity for knowledge of a defective or unwholesome condition is wholly irrelevant to his liability on the theory of implied warranty, and the question certified must therefore be answered in the affirmative. As already indicated, we do not feel that the inquiry in terms either requests a response on the ultimate issue of liability in this case or requires any comment on the disposition of issues between the court and the jury under the law relating to scope and breach of the implied warranty that a product supplied for human consumption shall be reasonably fit and wholesome for that general purpose.”
The Court went on to say, however,
“The contention that the wholesomeness of a product should be determined on any standard other than its actual safety for human consumption, when supplied for that purpose, * * * [is] one which we are persuaded has no foundation in the decided cases.” [Again emphasis ours].
Six months later, again with Judge Cameron dissenting, this Court held that it could not enter judgment for the plaintiffs on the issue of liability, 325 F.2d 673, for the reason that:
“The Florida Supreme Court’s rule is only that a product must be ‘reasonably fit and wholesome’ and have a ‘reasonable fitness for human use or consumption’.”
With deference, we feel that this view overlooked the language italicized immediately above but the views of the prior panel would be binding upon us, of course, were it not for developments later to be discussed.
The Court of Appeals further pointed out that on the first trial of the case in the District Court the jury, at the request of the plaintiffs, had been charged that “The manufacturer of products which are offered for sale to the public in their original package for human consumption or use impliedly warrants that its products are reasonably wholesome or fit for the purpose for which they are sold * * The adverb “reasonably” to modify “wholesome or fit” had been inserted in the instruction at the consent of the plaintiffs. The original Panel then said, “As a part of the law of this case the parties are, therefore, bound by the scope of the implied warranty as so defined by the District Court”.
This was followed by the crucial determination, 325 F.2d at page 677, that the jury had not made any sufficient finding on the question of reasonableness, that is, as to whether or not the cigarettes were “reasonably fit and wholesome” and therefore the defendant was not foreclosed from developing that issue on another trial.
[101]*101We then directed:
“[T]he parties are nonetheless bound by the jury’s answers to the written interrogatories [and] may not relitigate the issues thus already decided [that smoking Lucky Strike cigarettes was one of the causes of the cancer and that the cancer was one of the causes of the death] under the guise of presenting evidence on the issue of reasonableness, that is, as to whether the cigarettes were reasonably fit and wholesome.”
Judge Cameron, concurring in part and dissentiiig in part, was of the view that the warranty “Was that the cigarettes purchased by [Green] would not do him harm” and that the plaintiffs should not be required to show “that the cigarettes were not reasonably fit and wholesome for use by the general public”.
As far as we can tell, the parties made no further effort to obtain the direct, positive answer of the Supreme Court of Florida to that part of the original question which had propounded the inquiry, “Does the law of Florida impose on a manufacturer and distributor of cigarettes absolute liability, as for breach of implied warranty * * * [?]”.
The plaintiffs might well have been encouraged to do so in view of the language which the Florida Court had added to the effect that actual safety for human consumption was the standard for the determination of the wholesomeness of a product.
The result of the foregoing was that the case went to a second jury trial in which, pursuant to the opinion of 325 F.2d 673 the sole issue (and any factor not inconsistent therewith) was whether the cigarettes used by Mr. Green were reasonably fit and wholesome for human use, the parties being expressly commanded not to attempt to relitigate the already established facts that Green died of lung cancer and that the cigarettes were a cause of that cancer.
The jury verdict again was for the Tobacco Company. The judgment thereon was dated November 27, 1964.
The date is significant for, thereafter, on May 5, 1965, in the case of McLeod v. W. S. Merrell Company, Division of Richardson-Merrell, Inc., 174 So.2d 736, the Supreme Court of Florida stated that Green v. American Tobacco Company, Fla., 154 So.2d 169, was:
“A suit against a manufacturer. It involved a commodity which was available indiscriminately to the public generally. Green can be summarized as a case which applied a rule of absolute or strict liability to the manufacturer of a commodity who had placed it in the channels of trade for consumption by the public generally”.
I.
We now come directly to the question of whether the Judgment under review is to be affirmed or reversed.
We are confronted with specifications that the District Court erred in the following respects:
1. In denying Plaintiff’s Motion for Directed Verdict on the Issue of Liability made at the close of the defendant’s case and renewed at the close of all the evidence as the evidence conclusively established defendant’s breach of implied warranty of reasonable fitness for human consumption and use. * * *
2. In charging the jury that a breach of implied warranty of reasonable fitness for ' human consumption and use occurs only if defendant’s cigarettes endanger “any important number of cigarette smokers — any responsible number — any large segment * * any responsible segment of the general public * * * as to the threat of lung cancer,” such surprise charge having effectively directed a verdict for defendant * * *.
3. In permitting defendant’s expert witnesses to testify that they do not know the cause of lung cancer and that nobody knows the cause of lung cancer * * *.
4. In excluding certain kinds of evidence, i. e., testimony concerning (1) animal experimentation and (2) [102]*102the ‘Report of the Surgeon General’s Committee’ and other scientific authorities as well as work done by the testifier with other persons * * *.
We shall dispose of minor matters first.
In our view, the trial court denied both sides an opportunity to offer evidence of out of court experiments on animals and this was not erroneous, Bish v. Employers Liability Assurance Corp., 5 Cir., 1956, 236 F.2d 62; Travelers Insurance Company v. Wilkes, 5 Cir., 1935, 76 F.2d 701.
Neither did the Court commit reversible error in declaring inadmissible the surgeon generals report, Bish, supra; Rice v. Clement, Fla.App., 1966, 184 So.2d 678.
Of course, an expert may give an opinion based on the results of experiments by others and in that connection may describe such experiments, Woelfle v. Connecticut Mut. Life Ins. Co., 8 Cir., 1939, 103 F.2d 417, 418; Cf. International Paper Co. v. United States, 5 Cir., 1955, 227 F.2d 201, 208. We have previously indicated our acceptance of the majority view that experts may not be cross examined by the use of scientific works unless they relied on the very work which the cross examiner wishes to use, Bish, supra.
We cannot reverse for the giving of the charge described in Specification No. 2. The giving of this supplemental charge was caused by a controversy after the jury had retired as to whether the Court had inadvertently used the word “admissions” instead of “findings” [of the jury in the first trial]. Out of a commendable desire to clear up any possible chance of error on this point, the Court had the jury called back into the courtroom, after which this took place:
“THE COURT: * * * I also told you that the question was one of a common danger to the general public as distinguished from Mr. Green. That is for your determination. And if these cigarettes did endanger any important number of cigarette smokers —any responsible number — any large segment of those smokers — then it would be a breach of the implied warranty for fitness, which is imposed upon the manufacturer who sells the cigarettes. If they did not, there would be no breach of warranty * *.
“MR. HASTINGS [Plaintiffs’ counsel] : May we approach the bench ?”
(Side Bar Conference out of the hearing of the jury)
“THE COURT: Counsel do not like the words ‘important number’. They think that it is a little bit too definite. I mean does it endanger any responsible segment of the general public. Does cigarette smoking endanger them as to the threat of lung cancer? If it does, the implied warranty is violated.”
From the foregoing it is quite plain to us that plaintiffs’ counsel did object to the language of the supplemental charge, but he did not make the content of his objection a matter of record. Obviously, the Court then attempted to amend the charge so as to eliminate the objection, whatever it was. Thereafter, counsel offered no further exception. As amended, the language as to important numbers or large segments was, in effect, withdrawn. Thus, if there was any error in the amended supplemental charge, viewed as a whole, which we doubt, it certainly was not plain error. Therefore, in the absence of exceptions properly reserved we do not now consider it, Rule 51 Fed.R.Civ.P., 28 U.S.C.A.
Nor do we find any merit in appellants’ contention that they were entitled to a directed verdict on the issue of liability. It is argued that the defendant’s evidence was valueless and that this panel should now overrule the prior decision which constituted the law of the case on the second trial. Going to the heart of the matter, we simply say that the District Court had to retry the case under the directions he had received from this Court. The value of the evidence and all inferences reasonably to be drawn [103]*103therefrom, was as of the date of that particular trial for the jury to decide.
The second trial was a forensic battle of experts. The testimony of plaintiffs’ expert witnesses tended to show that cigarette smoking causes approximately 10% of heavy [as the witnesses defined the term] cigarette smokers to die of lung cancer after about twenty years of smoking.
Appellee met this proof in the following manner:
Dr. Moran testified that in his studies and research he had attempted to find out the cause of lung cancer but, “I don’t know the cause of it”. To this point there was no objection. Dr. Moran was then asked if he had any reasonable medical opinion as to whether or not the smoking of cigarettes has any bearing upon lung cancer. The plaintiffs’ objection was overruled. The witness then testified:
“Q. Can you say with reasonable medical certainty that smoking of cigarettes is the cause of lung cancer in the public?
A. No, sir.
Q. Do you know what does cause lung cancer or cancer in any other part of the body of a human being?
A. No, sir.”
This was followed by other testimony:
DR. T. L. JACKSON:
“Q. Since you are in the cancer field, Doctor, do you know the cause of cancer?
A. I do not know the cause of cancer.
******
Q. Do you know of any definite link between smoking and lung cancer in people who smoke ?
A. I do not know of any actual proven fundamental link between cigarettes and lung cancer * * *»
No objection was made to this testimony.
DR. HOCKETT:
“Q. Doctor, do you know the cause of cancer in the human body?
A. No, sir, I do not.”
DR. FLIPSE:
“Q. Do you know the cause of lung cancer?
A. No.
Q. Do you think there is any causal connection between smoking and lung cancer?
A. Personally I don’t believe there is; but that is a question that I cannot decide because we don’t know the cause.”
The following exchange then occurred:
“[DR. FLIPSE] We know many of the basal conditions that go with a change of cancer, but we don’t know the cause.
Q. Sir, would you name some of the things that medicine is working on now to try to determine if that is a cause or is related to the beginning of cancer?
MR. HASTINGS:
We object. One of the bases if repetitious and, too, this is not related to whether cigarettes are or are not the reason — are reasonably fit for human consumption.
THE COURT:
Doctor, only speak as to your own knowledge, what you know. He is not asking you what you suspect but what you know.
I believe you answered part of it. Nobody knows the cause of cancer; is that right?
THE WITNESS:
Nobody knows the cause.
You mean what he knows or what he suspects is the cause of cancer based upon his medical experience.
MR. BRADFORD:
Answer that question.
[104]*104A. Please read the question.
Have you arrived at any conclusion based upon your medical knowledge as to the suspected causes of cancer?
I have not.”
Finally Dr. Flipse testified on cross examination,
“We cannot say it is due to something we inhale * * *. Basically, we don’t know what causes it.”
When the defense rested, the attorney for the Greens made the following motion:
“MR. HASTINGS:
Your Honor, before we recess, we would like to move to strike the testimony of Dr. Burford, Dr. Flipse, Dr. Little and Dr. Jackson, who gave opinions to the effect that there was no relationship between smoking and cancer on the basis that the Fifth Circuit clearly stated that any evidence adduced with regard to this must assume as conclusively established the fact that one man, Edwin Green, had died of cancer of the lung as a result of smoking; and therefore we feel that the testimony by these witnesses should not be considered.
Denied.”
It will now be recalled, and it is appropriate that we should emphasize it, that the prior jury had expressly found that smoking Lucky Strike cigarettes was one of the proximate causes of the cancer and that the cancer thus caused was, in turn, one of the proximate causes of death. We likewise recall the emphatic, explicit instructions of this Court when it remanded the case that the parties were bound by these findings and that the parties could not relitigate the issues thus already decided under the guise of presenting evidence on the issue of reasonableness.
Appellee says that this line of testimony should have been admissible for the reason that if the cause of cancer is unknown then it cannot be said that cigarettes [as a cause of cancer] are not reasonably fit and wholesome for consumption by the general public. We do not feel that juries may be required to return verdicts on choices between mutually impossible propositions. Although the jury in this second trial was unalterably bound, and so informed, by the finding of its predecessor that cancer had indeed been a cause of the death of Mr. Green and that smoking Lucky Strike cigarettes had been one of the proximate causes of that cancer, it repeatedly heard from experts which it had the inherent province of believing, if it chose, that such could not possibly be true since none know the cause of cancer and, therefore, cannot prove the cause. That was not the standard upon which this Court directed that the case should be retried. There was express direction that the cause of death must not be relitigated in the course of settling the question of reasonable safety for use by the general public.
In all fairness, we must likewise recognize the equally distressing predicament of the trial judge. At the first blush he was presented with the previously determined fact that deceased had died from the use of a product, and then he was told to preside over the determination of whether such a product nevertheless was reasonably safe for use by the general public.
The answer to this dilemma, in our judgment, was that appellee could have rebutted plaintiffs’ proof as to the incidence of lung cancer in cigarette smokers without presenting testimony categorically contradictory to that which had already been found as a fact.
For these reasons, this judgment must be reversed and remanded for a new trial.
II.
The matter does not end here.
In the absence of some material change of controlling state law, occurring since the date of our former decision, December 11, 1963, 325 F.2d 673, [105]*105the directions of our former remand remain the law of this case and would have to be adhered to on the second remand.
On the other hand, if there has been a material change in the controlling state law, either by enactment or by clarifying interpretation, we are bound to follow the law as it now exists. Vandenbark v. Owens-Illinois Glass Co., 311 U.S. 538, 61 S.Ct. 347, 85 L.Ed. 327 (1941); Huddleston v. Dwyer, 322 U.S. 232, 64 S.Ct. 1015, 88 L.Ed. 1246 (1944); Jones v. Schellenberger, 7 Cir., 1955, 225 F.2d 784, cert. denied, 350 U.S. 989, 76 S.Ct. 476, 100 L.Ed. 855 (1956).
After the argument of this appeal we requested the parties to file, and we have received, briefs on the question of whether such a change has, indeed, taken place.
There no longer remains any doubt of the power and duty of this Court in proper cases to direct the entry of a judgment n. o. v., Neely v. Martin K. Eby Constro. Co., Inc., 386 U.S. 317, 87 S.Ct. 1072, 18 L.Ed.2d 75 (1967).
We have heretofore referred, at page 100, to the language of the Supreme Court of Florida when it answered our certified question, as follows:
“The contention that the wholesomeness of a product should be determined on any standard other than its actual safety for human consumption, when supplied for that purpose * * * [is] one which we are persuaded has no foundation in the decided cases.”
We must emphasize the words “actual safety” appearing in the above passage.
Then, as already pointed out, page 101 ante, after the second trial below [the trial now under consideration] the Supreme Court of Florida, in McLeod v. W. S. Merrell Co., Div. of Richardson-Merrell, Inc., supra, May 5, 1965, took occasion to explain what it had meant in Green v. American Tobacco Company, Fla., 154 So.2d 169. It said that on the facts of this case it had applied the rule of absolute or strict liability (see quotation alluded to).
On April 28, 1965, the Supreme Court of Florida decided the case of Foley v. Weaver Drugs, Inc., 177 So.2d 221. The accused product was a bottle which contained reducing pills. When the prospective user attempted to open the bottle by unscrewing the top it broke, fragmented, and thus lacerated her right wrist. Suit was brought on negligence and breach of implied warranty. The Supreme Court held that a retailer’s implied-warranty liability as to food did not extend to this container. In the course of arriving at this decision, however, and referring to cases previously decided as to tinned meat, and canned sardines,3 the Court stated that it had [106]*106twice previously affirmed the principle that
“ * * * as to items of food or other products in the original package which are offered for sale for human consumption or use generally, a person who purchases such items in reliance upon the express or implied condition or assurance that they are wholesome and fit for the uses or purposes for which they are advertised or sold, and who is injured as the result of the unwholesome or deleterious substances therein which are unknown to the buyer, may hold either the manufacturer or the retailer liable in damages for injuries sustained by him, on the theory of an implied warranty of wholesomeness or fitness of such article or product for the purposes for which it was offered to the public”.
Foley was decided two years after our original remand and directions in this case. The significant thing is that as to products intended for human use generally neither McLeod nor Foley anywhere modified or limited the requirement of fitness or wholesomeness to “reasonable fitness” or “reasonable wholesomeness”.
On February 9, 1965, the District Court of Appeal of Florida, Third District, Renninger v. Foremost Dairies, Inc., 171 So.2d 602, cert. denied, Florida Supreme Court, 177 So.2d 480, decided Renninger v. Foremost Dairies, Inc., involving a defective milk bottle. While imposing the reasonable fitness limitation to this object not intended for human consumption, the court nevertheless quoted verbatim the foregoing passage from Foley.
In the light of these decisions, rendered subsequent to our former opinion, we are now left in no substantial doubt that under Florida law the decedent was entitled to rely on the implied assurance that the Lucky Strike cigarettes were wholesome and fit for the purpose intended and that under the facts found by the jury his personal representative and widow are entitled to hold the manufacturer absolutely liable for the injuries already found by a prior jury to have been sustained by him.
This being so, in addition to reversing this judgment and remanding for a new trial we must also direct the District Court to enter judgment for the plaintiffs on the issue of liability and to submit the issue of damages to another jury.
Reversed and remanded, with directions.