xxiv Journal of Comparative Neurology. 



very probable that all vertebrates have a single olfactory lobe and 

 identifies it unquestioningly in the human embryo. Another conclu- 

 sion which may be recognized as conforming to views expressed in 

 this journal is that there is no secondary prosencephalon but the hem- 

 ispheres constitute a dorsal appendage which the author calls epen- 

 cephalon despite the use of the term by most authors for the cerebel- 

 lum. The three embryonic vesicles remain the distinctive regions of 

 the brain. There is no subsequent longitudinal partitioning but, on 

 the other hand, the prosencephalic vesicle suffers many secondary 

 modifications. Dorsally is the pallium of the cerebrum, that of the 

 diencephalon, the paraphysis, and the epiphysis, and ventrally the 

 optic vesicles and the infundibulum with its appendages. The eye 

 vesicles develop from a single median vesicle. 



The enormously developed infundibular region is termed " Hy- 

 pencephalon. " 



Kupffer agrees with Osborn that the cerebellum is primarily a 

 commissure but he does not accept his conclusions respecting the 

 intersegmental value of the commissures and accepts Burckhardt's posi- 

 tion respecting the roof of the diencephalon. It cannot be doubted 

 that the pineal proper always arises caudad of the supra-commissure. 

 This the present writer has conclusively observed in amphibians. 

 The whole matter has been well cleared up by Edinger and Burck- 

 hardt. The olfactory plate is regarded as homologous with the olfac- 

 tory pit of amphioxus. The hypophysis arises from a distinct funda- 

 ment ventrad of the olfactory plate. 



The hypophysis is regarded as a " palaeostoma " or rudiment of 

 the primitive mouth. If this is accepted we do not see why this 

 should not be regarded as evidence that the related cerebral region is 

 the actual front of the brain. The paper is well illustrated and 

 absorbingly interesting. 



Open Pharyngeal Clefts in the Human Enibrjo.' 



Although it has been recognized since the time of Rathke that 

 amniates as well as anamniate vertebrates posess well defined visceral 

 or gill arches during part of their life it would seem that the occur- 

 rence of open clefts in the former groups, in which the gills never de- 

 velop, must have simply an ontogenetic significance. In the work 



^ EuGEN Tettenhamer. Ueber das Vorkommen offener Schlundspalten 

 bei einem menschlichen Embryo. Ali'tnchener niedicinisclie Abhandhingcn, VII. 2. 

 J. F. Lehman, Munich, 1892. Price, i mark. 



