6l8 Journal of Comparative Neurology and Psychology. 



low power objectives and its course has been demonstrated to many 

 persons at two meetings of the American Association of Anatomists 

 and elsewhere. 



The general morphological relations are to be seen from Figs. 13, 

 14, 15, 16. In a section through the roots of the trigeminus (trans- 







Fig. 15. A transverse section ol the brain of tlie embryo H. 19 through the 

 trigeminal roots. The mesencephalic bundle lies imbedded in the sensory root, 

 widely sepai'ated from the motor root. 



verse section at this level) the sensory and motor roots are separated 

 by a considerable interval, as is usual in mammalian embryos. The 

 distinctness of the motor root from the sensory root and ganglion 

 peripherally is well known. The section of the brain shows a very 



