474 MONTGOMERY. [Vol. XV. 



Colossal ganglion cells (Figs. 90-92, 94-97). — In the nuclei of 

 these there are never more than from one to three nucleoli, 

 which neither contain vacuoles nor become noticeably irregular 

 in size, as is the case in Doto. Most frequently only a single 

 nucleolus is present. It is the rule that they are oval and not 

 spherical, though in some cases they may appear perfectly 

 spherical ; perhaps the great majority of them are oval and 

 seem to be spherical only when they do not chance to be longi- 

 tudinally sectioned. Their substance is perfectly homogeneous, 

 without a limiting membrane. When two or three occur in the 

 same nucleus they are usually of approximately equal dimen- 

 sions (Figs. 94 and 95). Further, it would seem to be the rule 

 that when one nucleolus is present in a nucleus it is larger than 

 any one of the two or three which may be found in other 

 nuclei ; but, nevertheless, the relative amount of nucleolar 

 substance seems to vary in different nuclei. 



Ganglion cells of medium size (Fig, 93). — Here one or two 

 nucleoli are present in each nucleus, and these are of homo- 

 geneous appearance. 



Smallest ganglion cells. — The nucleoli are similar to those 

 of the corresponding cells of Doto. 



On a preparation preserved in Flemming's fluid I find many 

 of the nucleoli present a different structure from those fixed 

 with corrosive sublimate or Kleinenberg's fluid. Thus many 

 of them do not appear homogeneous, but finely granular and 

 refractive (Figs. 96 and 97). On the surface of such nucleoli 

 occur small, refractive, yellowish globules, which appear black or 

 yellow, according to the focus of the microscope ; some of them 

 are very small. These never occur within the nucleolus, but 

 only on its periphery. They may easily be distinguished from 

 the chromatin granules by their rounded form and high degree 

 of refrangibility, as well as by their deeper yellow color (this 

 preparation had been stained with haematoxylin and eosin, but 

 the nuclei had not become stained, probably owing to too long 

 a fixation in the fluid of Flemming). Numerous other nuclei 

 on the same sections showed none of these globules, and none 

 were to be seen on preparations which had been differently 

 preserved. Accordingly, I consider them to be artefacts. 



