6oo "Journal of Comparative Neurology and Psychology. 



iVptal human brains prepared after the method of Fleehsig. The 

 cells of origin have been studied in Scyllium, Squalus, Acipenser, the 

 toad, the rabbit, rat, and the human embryo. The preparations of 

 this embryo were demonstrated at the meeting of the American Asso- 

 ciation of Anatomists at Ann Arbor, in 1906, and the results of the 

 study of the mole, rat and cat were reported in a paper read at that 

 time. 



Instead of a systematic review of the findings in each of these 

 species, which would require a series of long and tedious descriptions, 

 it seems best to take up the important features which bear upon the 



Fig. 1. Camera drawings of cells of the uuolens maguocelhilaris tecti in 

 Scyllium showing their processes entering the radix mesencephalica trigemini. 



connections and function of this bundle. The more important points 

 have been clearly seen in all the species mentioned. 



1. The Origin of the Bundle. — So far as the cells in the locus 

 coeruleus of mammals are concerned, there has been no serious ques- 

 tion as to the origin of these fibers from the large vesicular cells since 

 this was first stated by ]\Ieynert. The demonstration of this by Cajal 

 by means of the Golgi silver method left nothing to be desired. As for 

 the cells in the mesencephalon of fishes (nucleus magnocel hilar is 

 tecti), I expressed some doubt in my earlier paper. At that time I 

 had not seen Van Gehuchten's paper and my preparations did not 

 show the entrance of processes of the large cells into the trigeminal 

 bundles. Later preparations of the brains of Scyllium canicula, S. 



