to M. Cost J s Memoir. 185 



M. Coste' s own assertions, and by the evidence of the artist 

 which he adduces to support those assertions. 



But before noticing these assertions, and that evidence, I 

 must offer a few remarks on the general dissertation on marsu- 

 pial developement, with which M. Coste involves the immedi- 

 ate question, because although this dissertation is set forth with 

 higher pretensions, it in fact consists, in all its essential points, 

 of a mere paraphrase of an imperfect translation of my first 

 Memoir of 1834. M. Coste says, "Nous soumettons au juge- 

 ment de TAcademie, une dissertation, qui sera a la fois la re- 

 futation de la lettre de M. R. Owen, et qui, en meme temps, 

 contiendra toute Thistoire connue de Tovologie du kangaroo." 

 Memoire, p. 3. The learning he deems requisite for this his- 

 tory, is restricted however to a mere repetition of the names 

 of the authors whose works are quoted in my Memoir. But 

 in that Memoir I did not pretend to enter into the whole known 

 history of the ovology of the kangaroo ; my aim was restricted 

 to the elucidation of certain doubtful points in the history of 

 marsupial developement ; otherwise I should have furnished 

 M. Coste with more names of authors of originality, than 

 those which appear in his dissertation. It is not, however, 

 my business here to occupy the time of the Academy, by de- 

 monstrating the poverty of M. Coste' s critical acquirements 

 on the subject he proposes to teach. But I may observe, en 

 passant, that if the recent admirable descriptions of Rengger 

 had been known to him, he would have been in possession of 

 evidence relating to the condition of the marsupial ovum, in 

 the multiparous species, of which he appears to be in igno- 

 rance; and I may add that if he knew the writings of Collie, 

 otherwise than by the extracts which are introduced into my 

 Memoir of 1834, he would be acquainted with phenomena 

 which are very essential to the man who, elevated by the ad- 

 dition of one new fact to his small stock of ideas on the sub- 

 ject, undertakes to teach the whole known history of the oology 

 of the kangaroo ; — "toute l'histoire connue de l'ovologie du 

 kangaroo." 



Yet even in the easy task of superficially paraphrasing a 

 statement of facts which he had no share in accumulating, M. 

 Coste cannot avoid falling into the errors which usually be- 

 tray a hasty compilation. And first, with reference to M. 

 Coste' s description of the female organs of the kangaroo, I 

 may observe, that there exist two interesting modifications of 

 these organs of the marsupials, one of which relates to 

 multiparity, the other to uniparity. In those marsupials 

 where ova are simultaneously developed in both uteri, the 

 median cul-de-sac is equally divided by a longitudinal septum, 



Q2 



