to M. Code's Memoir. 189 



me to the Academy, that I had removed the chorion in the dis- 

 section of my second marsupial ovum, some weeks before its 

 exposed and naked contents were exhibited to M. Coste ? 



Returning, and I confess that it is more in sadness than in 

 anger, to this subject, I ask, in the second place, what are the 

 analogies adduced by M. Coste to induce the Academy to ac- 

 cept his imaginary, or, as he prefers to term them, inductive 

 views of the condition of the chorion, in my second marsupi- 

 al ovum ? 



M. Coste asserts that in other Mammalia it becomes im- 

 possible, at a certain epoch, to separate the chorion from the 

 vesicula umbilicalis^ — and he appeals to all the physiologists 

 who have made the same researches as himself, for the truth 

 of this assertion. "Nous savions," says he, "que chez les au- 

 tres mammiferes, il devient impossible, a une certaine epoque, 

 d'isoler le chorion de la vesicule ombilicale :" p. 15. 



Now this statement may be understood as referring either 

 to a partial or total fusion of the chorion with the umbilical 

 sac ; if to the former, it tells against M. Coste' s analogical ar- 

 gument, because he then admits that a certain proportion, (and 

 it is always a large one), of the chorion is left free for removal; 

 but we must suppose that M. Coste is here speaking of the 

 chorion in totality, in the sense in which he described to the 

 Academy the chorion of the kangaroo. We can only marvel 

 at the profundity of the recent researches which have conduct- 

 ed M. Coste to such a generalization. Nevertheless, we have 

 seen that embryology is not yet reduced, even by M. Coste, to 

 that exact science which will enable an anatomist with safety 

 to describe a chorion which he never saw. M. Coste then goes 

 on to say, — "dans l'ceuf que M. R. Owen nous aremis, le de- 



a ecrire cette lettre, nous dirons que ce n'est point un fcetus qu'il a eu 

 l'obligeanee de mettre a notre disposition, mais bien un ceuf complet, c'est 

 a dire, un embryon, avec son amnios, sa vesicule ombilicale, son allanto'ide 

 enveloppe dans les replis de cette derniere, et sa membrane vitelline, ou 

 chorion. II est vrai que M. Owen, pour prouver que ce n'etait pas un ceuf, 

 affirme que dans ce qu'il nous a remis, cette derniere membrane n'existait 

 point ; et comme preuve de son negation, il annonce que quelques semaines 

 avant lors de la dissection qu'il dit avoir faite de cet ceuf, il aurait enleve 

 le chorion. Lorsqu' un homme du caractere de M. R. Owen avance un 

 pareil fait, on doit Ten croire ; il n'est pas convenable d'elever des doutes a 

 cet egard." 



The motives which induced me to write the letter to the French Acade- 

 my, (printed in the February number of this Magazine), require little pene- 

 tration to decipher ; they were simply to unmask a pretender, who sought 

 to appropriate to himself a discovery which did not belong to him, and who 

 supported his claims before the Academy, by boldly describing a part which 

 he had never seen. 



q4 



