72 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



which it apparently furnishes food material. The granules, 

 too, strongly suggest the yolk granules present in animal 

 eggs. They appear in small quantities in the pollen-mother- 

 cells at an early period, but their exceedingly rapid increase 

 at the time when the first steps in the actual formation of 

 the spindle takes place strongly impresses one with the idea 

 that the cytoplasm is busy producing nutritive material to 

 serve the cell through the period of its activity. 



The manner in which the granular zone accumulates sug- 

 gests the gathering of the deutoplasm in animal eggs (Wil- 

 son, 1896, p. 115 et seq.). In Passijlora it appears first in 

 patches scattered through the cytoplasm and later gathers 

 into a somewhat loose ring at some distance from the 

 nucleus. This is the way in which the yolk collects in the 

 egg of Dicmyctylus and other Amphibians, as described by 

 Jordan (Wilson, 1896, p. 116). 



In CobcBa and Lavatera the granular substance appears 

 first close around the nucleus and spreads out from this as 

 in the trout (Henneguy) and cephalopods (Ussow) (See Wil- 

 son, 1896, p. 117). The exceedingly dense zone formed 

 by this substance in Lavatera exactly resembles that figured 

 by Van Bambeke for a fish (Scorpcena) (Wilson, 1896, p. 

 116, fig. 59, C). In some cases, as Cobcea, the granular 

 matter is used up as the divisions are completed. In Lava- 

 tera, however, it constantly increases in quantity up to the 

 formation of the pollen-grains in which it is present, at 

 least in the younger stages. It seems probable that it per- 

 sists in them and serves them for food during the develop- 

 ment of the pollen-tube and the succeeding divisions. 



