54 



metbylen-blue, ttisy exhibit the typical dense nuclear struct- 

 ure and the small amount of cytoplasm. 



b. Purhinje neurones. — The phylogenetic interest attach- 

 ing to the presence in the oblongata of these eleir.ents calls 

 for more special notice. The Purkinje neurones of the tuber- 

 culusr acusticum are not disposed in any regular order. They 

 lie scattered between the deeper molecular neurones, and they 

 are also found among the granular neurones. Their dendrites 

 are always directed toward toe limitans externa, whatever the 

 situation of the cell-body may be, although the exact course 

 may be at a considerable angle to the perpindicular. The axone 

 always passes inward. Refer to Big.?, t.a. 



The cell-body is slightly oval or even perfectly circular 

 in outline (Fig. 7). The particular form assumed appears to be 

 correlated with the position of the dendrites. The gnarled 

 character of a dendrite is quite evident. There are three or 

 four of them, terminating in blunt tips. A dendrite bears few 

 branches, or none at all, and its surface is studded with numer- 

 ous thorny gemmules of various sizes, some of them quite large. 



The axone arises from the internal border of the cell. 

 It takes a ventral course through the intervening nervous tissue 

 into a bundle of arcuate fibres. Its ultimate distribution 

 has not been definitely followed. 



The internal structure presents a large nucleus with deep- 

 ly staining chromatin in the form of a reticulutr; and cytoplasm 



