1 6 'Journal of Comparative Neurology and Psychology. 



distally in small bundles in a group of cells situated laterally of the 

 ventricle. Figs, xx and xxi clearly show this termination of the 

 decussatio inter-hemispherica, which may also be called tractus 

 olfacto-epistriaticus cruciatus. We find, moreover, in the latter 

 region the termination of uncrossed fibers which likewise originate 

 from the area olfactoria posterior, the tractus oljacto-epistriati- 

 cus hornolateralis. For this part of the fore-brain, which surely 

 belongs to the olfactorium but cannot be reckoned with the area 

 olfactoria posterior itself, I choose the name epistriatuni, in con- 

 nection with which I will say no more, however, than that it has 

 an olfactory character and is situated in the immediate neighbor- 

 hood of the striatum. The precise character of this region de- 

 pends on the nature of the crossed and uncrossed tracts described. 

 The uncrossed tract originates, as I have said, in the same nucleus 

 where the decussating tract begins and about the latter there is 

 some difference of opinion. 



Romano, who described this decussation in Scyllium, considered 

 it as a commissure between cortical olfactory centers, which in my 

 type could be the case only if we ascribe cortical functions also to 

 what I call the epistriatum. Botazzi also, who described the decus- 

 sation before Romano and justly called it a decussation and not a 

 commissure, does not believe that it presents direct olfactory 

 tracts, whose decussation he observed only in the commissura 

 anterior. Both consider the decussation as a functional analogue 

 of the corpus callosum, which, however, cannot be under any 

 circumstances, if, as Edinger maintains, w^e are to consider the 

 callosum as connecting non-olfactory cortical layers with each 

 other. Catois describes them as, "fibres affectees a la voie 

 olfactive," as to which there can be no doubt, and he justly con- 

 siders them as psalterium rather than as callosum, as they are 

 decidedly connections of the olfactory parts of the pallium. As 

 for me, I think they must be considered as decussated connections 

 between the area olfactoria posterior and another olfactory center 

 which is probably a more distal continuation of the more frontal 

 center. As was first described in the teleosts by C. L. Herrick 

 and since confirmed by Dr. Goldstein for many fresh water 

 fishes and by me for Salmo salar, we find here a bilateral connec- 

 tion of the area olfactpria posterior lateralis, an area which in 

 these fishes has not so enormous a fronto-distal extent as in sela- 

 chians. 



