( 467 ) 



XVIII. — On the Gravid Uterus and on the Arrangement of 'the ■ Foetal Membranes 

 in the Cetacea. Plates XVII. and XVIII. By Professor Turner. 



(Received 20th March 1871.— Read 3d April). 



CONTENTS. 



PAGE 



Introduction, ..... 487 



Uterus and Appendages, . . . 470 



Fcetal Membranes, .... 478 



Position and General Form of Foetus, . 484 



Comparison of Placentation with that of 



other Mammals, .... 486 



Physiological Conclusions, . . . 498 



The distinguished French naturalist, Professor H. Milne Edwards, in the 

 ninth volume of his valuable Lectures on Comparative Anatomy and Physiology, 

 published only last year, when referring to the foetal membranes in the Cetacea, 

 states, that much information is still required to complete our knowledge of 

 that subject."" 



It may perhaps be advisable, before I commence to describe the results 

 arrived at by my recent dissections, to give a brief account of the observations 

 made by previous inquirers into this department of anatomy, so that we may 

 more clearly recognise wherein our deficiencies lie, and the direction in which 

 our researches ought to be conducted, in order to render our information as 

 complete as possible. 



Karl Ernst von Baer in his celebrated memoir, " Ueber Entwicklungs- 

 geschichte der Thiere,"t says, " I know nothing of the ovum of the cetacea from 

 my own observations ; the scanty notices which we find on this subject in 

 anatomical literature at least show that there is no definite placenta, and lead 

 us therefore to suppose that the ovum is similar to that of the pachy dermata. " 



D. P. Eschricht in an academic dissertation, published in the same year as 

 Von Baer's memoir, recorded the dissection " DelpMni phocwnw gravidi."\ He 

 described the free surface of the uterine mucous membrane as rugose, cellular, 

 and cribriform. The surface of the chorion was strongly marked by rugae, 

 which could not be obliterated. Almost the whole surface was covered by * 

 villi, which were separated from each other by intervals of nearly half a line. 

 The villi possessed narrow stalks, and their free ends expanded into a globular 

 branching crown, like the head of a cauliflower. In the hollows between the 

 rugae very small villi were found. A beautiful capillary network was situated 

 within the crowns of the villi. The villi were adapted to the little recesses or 



Lecons sur 1'ana.toniie comparee, vol. ix. note, p. 563. Paris, 1870. 

 + Second part, p. 257. Konigsberg, 1837. 



Tie organis qu?e respirationi et nutritioni foetus mammalium inserviimt. Hafnia:, 1837. 



VOL. XXVI. PART II. 6 F 



