Literary Notices. Ixxv 



similar nature, the subject corresponding to the simpler, the object of 

 the judgement to the more complex act of perception. The sequence of 

 words m all languages substantiates this view, for each word forms 

 a psychological subject for the next following. 



The usual methods of determining the discrimination time are 

 imperfect. We should not attempt to measure the time required to 

 distinguish the expected from the received impression but rather to 

 determine the time necessary to become conscious of the difference 

 between two simultaneous objects and compare this with the time re- 

 quired to recognize the objective similarity. The act of choice occu- 

 pies a longer time because in its simplest form at least four concepts 

 are necessary — that of two sensations and of two motor responses. 

 This time has, therefore, no relation to the act of volition. 



The above theory corresponds well with the facts of comparative 

 psychology. In a single act of perception man passes in hundredths 

 of a second through stages which have required for their develop- 

 ment unnumbered ages in the evolution of the animal consciousness. 



The Olfactory Apparatus and Hippocampas.^ 



It will be remembered that Edinger, in 1888, identified a part of 

 the free mantle of reptiles as Amnions cortex or homologue of the 

 hippocampus. A similar position was taken by Koppen, Schulgin 

 and Herrick, although Edinger curiously misunderstands the position 

 of the last. 2 



In discussing the connections with the olfactory apparatus Dr. 

 Edinger says: "Anatomy has revealed a large number of fibre 

 tracts which spring from the olfactory lobes and end in the lobus pyr- 

 iformis. These tracts, the olfactory nerve roots, have usually been 

 interpreted, as long as the pero of the tuber was considered a true 

 cortex, as long associational bundles which connect the olfactory cor- 

 tex with distant caudal parts of the cortex. Recently, however, 

 Cajal, Gehucten, Koelliker, Retzius and others have shown that the 

 first centres of the olfactory nerve lie in the pero of the bulb. The 

 fibres connecting this grey matter with the cortex, i. e. the so-called 

 "roots," acquire an entirely new significance. They must be called 

 projection fibres for the olfactory sense and are analogous with the 



'Edinger, L. Vergleichend entwickelungsgeschicliche und anatomische 

 studiem im Bereiche der Hirnanatomie, 3, Riechapparat und Ammonshorn. 

 Anat. Anzeiger, VIII, lO, II. 



'^See elsewhere in this number. 



