558 MAYNARD M. METCALF, 



some, at least, of these cells, send nerve processes directly into the 

 nerves at whose bases they He. One of these large cells, isolated by 

 maceration, is shown in Plate 40, Fig. 91 1. It is seen to have one 

 chief process arising from the pointed end of the cell, while from 

 the more rounded end several fibres arise. These latter were directed 

 toward the ganglion and ran in among the cells of its peripheral area. 

 The long process from the pointed end of the cell entered a small 

 nerve at whose base the cell lay. Similar cells are found throughout 

 the horizontal zone of the brain, from which the nerves arise. 



In frequent instances one can see that not all the fibres of a 

 nerve arise from the cells that lie immediately at its base, for, in 

 successful preparations, one can trace an individual fibre from a nerve 

 trunk for some distance into the core of the ganglion. 



The smallest cells of the periphery of the brain have a small 

 cell body almost completely filled by the nucleus. I have not found 

 fibres arising from these smallest cells (cf. Fig. 91 2). 



Many cells intermediate in size between these two extremes are 

 found. One such is shown in Fig. 91 3. These may show several 

 processes. I have never been able to trace any of the processes into 

 a nerve trunk, though I have seen them entering a mass of fibres 

 evidently part of the core of the brain. These cells seem to form an 

 intergrading series between the cells of the smaller sort and the large 

 cells in the zone of origin of the nerves. 



The fibres that lie interlaced in the core of the ganglion frequently 

 show varicosities along their course, as indicated in Fig. 91 4. 



The pigment cells of the eye are irregular cells with small nuclei 

 and large cell bodies full of brownish-red granules. Two such cells 

 with the pigment left out of account are shown in Fig. 90 1 and 2. 



The ciliated cells of the ciliated funnel are roughly columnar, 

 each having a single long cilium arising from the free end (Fig. 89 1). 

 Among these cells are found a few much more slender cells whose 

 basal end is pointed and is prolonged into a slender process which 

 appears to be a nerve process (Fig. 89 2). I have found but few of 

 these cells and have not, in any of them, seen anything like a cilium 

 or a bristle on their free end. Probably these cells are sensory. 



From the cubical epithelium of the upper, non-ciliated portion of 

 the ciliated funnel there were obtained in several cases cells such as 

 are shown in Fig. 89 3. At their free ends the cells figured show 

 a blunt process. I could not, in any case determine that any cilium 

 or bristle had been broken off from this process. The fibres, ap- 



