Wilder.] 54o [july 15^ 



Maltese and white, prep's 288, 289. Some details of the Area prcecJiias- 

 matica (the region cephalad of the chiasma) are from 461 and 527 ; of the 

 Ar. postpontilis (the region caudad of the pons) from 358, 454 and 491, and 

 of the intermediate A. cruralis from 422, 506, and 527. 



Most of the nerves and cerebral fissures are lettered on the right side, 

 and most of the other parts on the left. Some of the left nerves are cut 

 short, and the left N. trocMearis is not shown at all. 



The LoM olfactorii {LI. ol.), and are made too long, and the hypophysis 

 {hph.) is too short. 



Attention is called to the following points, chiefly in comparison with 

 the human brain : — 



The absence of a distinct Radix intermedia (Rx. in. ) of the Cms olfacto- 

 rium, corresponding with the so-called "middle root of the olfactory- 

 nerve" in man. The part so designated upon the plate is apparently only 

 an area, compai'atively undifferentiated, between the more or less fibrous 

 tracts forming the Radices mesalis and lateralis. 



The turning of the Rx. mesalis {Rx. ms.) over the margin of the brain so 

 as to appear upon the meson. 



The distinction of the Rx. lateralis {Rx. I.) into a lateral gray and a 

 mesal white tract, the Limes cinerea {Lm. cin.) and the Lm. alba. 



The great extent of the {Locus) proeperforatus {prpf.), audits division 

 into a cephalic more prominent portion {Pt. p.), and a caudal depressed 

 portion {Pt. d.). Both portions are "perforated," but the degree of fur- 

 rowing of the Pt. prominens varies considerably. These furrows exist in 

 some other Carnivora. 



The width of the hypophysis {Jiph.), and the crenation of its caudal border, 

 indicating the existence of an ental subspherical mass, which is covered 

 by an ectal layer, the thinness of which, in the caudal region, permits the 

 contour of the former to be seen. 



The slight degree of separation of the albicantia {abn.), which are here 

 nearly concealed by the hypophysis, but more fully shown in fig. 12. 



The distinctness of the cimbia {cmb.), or "tractus transversus pedunculi," 

 which is better seen in fig. 11. 



The slight extent of the true postperforatus [p^yf. ) ; the only part which 

 is really "perforated" is a small triangular area just caudad of the albi- 

 cantia, and partly hidden by them. 



The less caudo-cephalic extension of the pons {pn.) ; this exposes more 

 of the Area intercruralis {Ar. ic. ) than in man, and uncovers the trapezium 

 {tz.), which, in man, is wholly concealed. Connected also with this 

 feature of the pons is the fact that the JV. abdueens {N. abd.) passes 

 directly cephalad from its origin a little caudad of the pons, whereas in 

 man it is forced to curve around the caudal border. Finally, the N. trigem- 

 inus {N. trg.), in place of emerging through the pons as in man, arises 

 wholly caudad of it, although closely applied to its surface. 



The greater extent of the Ar. cruralis, which may be ascribed both to 



