ZOOLOGY. 471. 



Herrmauii (G.)' Sur la Spermatog^n^se chez les S^laciens. Compt. rend. Acad. Sc; 



Paris, t. 93, pp. 858-860, 

 Marshall (A. Milnes). On the Hoad Cavities and Associated Nerves of Elasmobranchs. 



Quart. Jouru. Mic. Sc, v. 21, pp. 72-97, 2 pi. 



Anterior termination of notochord in Selachians. 



It liadbeen generally supposed that the notochord in all fishes termi- 

 nated in front, back of the sella turcica, and this belief has been embodied 

 in diagnoses of those animals as contrasted with the lowest of the verte- 

 brates — the Leptocardiaus. Recently, however, the eminent German 

 embryologist, Professor Reichert, thought that he could trace the noto- 

 chord "through the cranial floor in front of and below the hypophysis." 

 Eeichert's observation was made on the embryo of a dog-fish {Sqiialus 

 aeanthias). Dr. Eabl-Ruckhard has re-examined the same species with 

 reference to the mooted question, and confirms the old view in opposition 

 to Professor Reichert. After an examination of several specimens he 

 formulated his conclusions as follows : 



1. "At no period of its development has the embryo of Aeanthias a 

 notochord with its apex projecting beyond that part of the base of the 

 skull which subsequently becomes the dorsum sellae." 



2. " The hypophysis arises immediately in front of the apex of the 

 notochord in the basal portion of that deposit of connective tissue which 

 is termed the middle cranial trabecula." 



3. "The summit of this rudiment (Reichert's processus sellae turcicse) 

 does not pass into the later sella turcica, but becomes the adveutitia of 

 the basilar artery." 



It is added that " though it is certain that the notochord stops short 

 of the hypophysis and lies behind (not beneath) it, this is not irrecon- 

 cilable with Reichert's other statement — that the chorda of young sharks 

 at a certain period of development reaches to the frontal wall {Stirn- 

 wand). The cephalic flexure shows us that such a state of things is 

 quite possible." 



Observations were also made on the morphology and development of 

 the hypophysis and pineal gland. The results of the lamented Balfour 

 are confirmed. In contradiction of Fritsch, it is maintained that " the 

 pineal gland is developed just as among the higher vertebrates." The 

 sources of error which have led to contrary assertions are explained. 

 (J. R. M. S., I, 9-11, from Morph Jahrb., VI, 535-570, 2 pi.) 



FISHES PROPER. 



p Chondrostei. 



Parker (William Kitchen). On the Development of the Sturgeon (Acipenser aturio). 



Nature, v, — , p. 71. 



Salensky (W.). Sur le Developpement de la Sterlet. Arch, de Biologie, t. 2 pp. 233- 



341, 8 pi. 



Apodes, 



Brock(J.). UntersuchungeniiberdioGeschlechtsorganeeinigerMuraenoiden. Mittheil. 

 Zool. Station Neapel, v. 2, pp. 415-494, 3 pi. 



