cxlvi Journal of Comparative Neurology. 



ered from its recurved position as different from other types. The 

 sulci upon its endymal surface are compared with those of Diemycty- 

 lus. The pallium is considered as a plexus much stretched, not as an 

 undeveloped part representing the dorsal and mesal walls of other 

 brains. 



[This is in effect a restatement of a theory frequently stated and 

 implied by the writer in several papers during the past four or five 

 years. In a paper in the Festschrift zum siebenzigsten Geburtstage Ru- 

 dolf Leuckarfs, p. 279, occurs the following passage: "In those 

 portions of the primary nerve tube which are to form plexiform struc- 

 tures the spongioblasts retain their primitive structure. In cases 

 where the development is delayed the original simplicity is retained 

 long after other regions have acquired a complicated neurologia. 

 Thus in very young Amblystoma (Plate XXVII, Fig. i) the temporary 

 palliurn which ultimately becomes the median walls of the prosenceph- 

 alon remains single-layered and exhibits only an occasional neuro- 

 blast." 



In other places it has been clearly stated that the axial lobe of 

 teleosts and ganoids is supposed to contain the elements which other- 

 wise would enter the cortex ; thus the pallium would correspond in 

 position and nature to the thm median walls of the ventricle. The 

 author of the paper before us takes a step farther in seeking to 

 definitely homologize the pallium with a specially modified part of 

 this wall — the plexus. This is probably a form of statement unsus- 

 ceptible to proof or disproof, because of the lack of means to deter- 

 mine whether a tela-form membrane might not be directly converted 

 into plexus.] 



9. Arguments and facts are given for considering the rhinencephal 

 as equal to other segments having a tripartite arrangement. [From 

 a strictly morphological point of view it would seem necessary to 

 settle the preliminary question as to the front of the brain tube be- 

 fore one could venture to ascribe regional independence to the 

 olfactory lobe. The term rhinencephalon is now so generally used 

 for the whole limbic region as to seriously compromise its availabilty.] 



We venture to express regret at the increasing custom of spelling 

 generic names without capitals, which seems an offense only second 

 to the capitalizing of specific names. In the present paper Diemyc- 

 tylus is uniformly spelled without capitals, while other genera referred 

 to are capitalized (viz. Cryptobranchus, p. 264). 



The paper is a welcome addition to the anatomy of the brain and 

 affords evidence of the hold morphology is taking in America. The 



