Literary Notices. cxlv 



2. The callosum and callosal eminence [intra-ventricular lobe] 

 are only beginning to develop in early larvas of Diemyctylus, and the 

 position of the cerebral commissures differs in early stages more from 

 the anurous type than does the adult, the aula being much larger pro- 

 portionally. The type in urodeles and fishes may be one of an ar- 

 rested embryonic development. [Cf. Journ. Coinp. Neurol., p. 136, 

 Sec. 4.] In the Diemyctylus there is evidence, in the adult, of a 

 caudal growth of the terma which if continued would bring the com- 

 missures in the same relation to the terma as in the frog and higher 

 forms. 



3. The crista in Diemyctylus and Amia is shown to be a defi- 

 nite structure beyond which the cerebrum develops cephalad and from 

 over which the auliplexus is reflected, and thus is a landmark in dis- 

 cussing the relations of the aula and cerebral commissures. [These 

 considerations might seem to suggest that the callosum might be ceph- 

 alad to the reflected plexus as in Opossum.] 



4. The paraphysis of Diemyctylus is traced through different 

 stages of development and homologies discussed in Amia and the 

 lamprey, and a possible use in the nourishment of the brain is sug- 

 gested. 



5. Sulcus is proposed as a general term for the furrows on the 

 endymal surface, which have a morphological significance and lophius 

 for the ridges between sulci. [If anatomists would agree to thus apply 

 a term which is certainly as much used as "fissure" for cortical 

 grooves, it might be well, but meanwhile the ambiguity which is 

 charged to the descriptive terminology introduced by the writer is not 

 removed. Moreover those fissures which are due to the deformation 

 of the cerebrum as a whole (1. e. to flexures of its axis, etc.) may im- 

 press themselves upon the axial lobe and, if the view suggested by the 

 writer that the axial lobe of fishes is but the undeveloped " proton " 

 of the whole cerebrum and not, as often represented, homologous 

 with the hemispheres minus the cortex, there might still be a sort of 

 reasonableness in a terminology which should suggest the homology, 

 however distant. These remarks apply particularly to the sylvian and 

 rhinalic depressions of the fish.] 



6. In the discussion of the geminums it is shown that homolo- 

 gies are not dependent upon the membranous or solid condition of the 

 roof nor the angle at which parts unite. 



7. The morphological relations of the pallium are considered in 

 Amia and its homolog in amphibia and the lamprey suggested. 



8. The cerebrum of Amia and other fishes is not to be consid- 



