xvi Journal of Comparative Neurology. 



finds six kinds of cells aside from the specific or mitral cells. The 

 granule cells have axis cylinders and dendrites and are therefore nerve 

 cells. There are also cells similar to the so-called cells of Cajal. As- 

 sociational cells with short axis cylinders are present in the glomerulary 

 zone. The large mitral cells are provided with non-glomerulary den- 

 drites. In the dorso-median region of the fore-brain there is a large 

 incompletely differentiated nucleus of cells with short axis cylinders 

 constituting an imperfect epistriatum. A group of cells on the lateral 

 surface of the fore brain agrees in position and apparently in connec- 

 tion with the cortex lateralis of Reptilia. The cortical region of the 

 fore-brain is connected with the ganglion habenulae by a tractus cortico- 

 habenularis and there is also a tractus olfacto-habenularis. Meynert's 

 bundles do not end in the interpedunculare, but undergo partial decus- 

 sation there and pass on towards the medulla. c. l. h. 



The Cerebellum of Fishes.^ 



After a brief description of the cerebellum of low types of Selach- 

 ians the author institutes comparisons with the same organ in the ganoids 

 and teleosts, chiefly as described by other writers. The result of the 

 comparison is to lead the author to the conclusion that the cerebellum 

 of the selachians is composed of two portions, the cephalic of which is 

 homologous with the volvula,i the other portion is strictly homologous 

 with the cerebellum of teleosts. The decussation of the trochlears is 

 thus still retained as the cephalic boundary of the cerebellum. In gen- 

 eral the very obvious suggestion of Strong, the Herricks and others 

 that the differentiation of the regions of the medulla oblongata is largely 

 influenced by the peripheral nervous distribution is again made 

 emphatic. c. l. h. 



The Development of the Retina According to Cajal. 



Professor R. Greef, who translated Ramon y Cajal's monograph 

 on the retina has given a full resume of the recent studies by the same 

 author as published in full in the Journ. de I'Anat. et dc la Fhys., Sept., 

 1896. 



The rods and cones arise as very similar unipolar cells attached 

 by stalks to the outer limiting membrane. Prior to this stage the visual 



' RuD. BURCKHARDT. Eeitrag zur Morphologic des Kleinhirns der Fische. 

 Arch.f. Anat. u. Phys. 1897. 



'^ This organ the author still calls the valvla cerebelli in spite of the false 

 homology involved. 



