SECRETION IN FOLLICLE CELLS. 2 19 



are most numerous in the cells of the B stage of the egg tube. 

 Within any given cell the distal droplets vary in size in a rather 

 regular manner, the smallest being nearest to the nucleus, often 

 applied to its membrane, the largest being adjacent to the 

 distal cell wall. When viewed from above, they often appear to 

 form a ring just above the nucleus (Figs, n, 12). This position, 

 and the fact of their gradation in size seems to indicate a close 

 relationship with the nucleus at the time of their origin. 



In the living cell these droplets stain red all the way through 

 with neutral red. But with toluidine blue and with janus green 

 only the outer rim takes on color. Nile blue sulphate has been 

 demonstrated by J. L. Smith to stain fats differentially; i.e., 

 neutral fats are stained red, and fatty acids blue, the degree of 

 acidity being indicated roughly by shades of lavender. When 

 the egg string is stained with nile blue sulphate, the distal 

 droplets show a pale red medulla with a deep lavender cortex. 

 The droplets stain as a whole with scharlach R after fixation in 

 formol; they are blackened after impregnation with osmic acid, 

 and after treatment with Champy's mixture of osmic and 

 bichromate. When tissues fixed with osmic acid are later treated 

 with turpentine, the medulla dissolves first, leaving an indistinct 

 gray base; the cortex dissolves only after long exposure. After 

 other treatments, such as Regaud's, Bouin's, and Da Fano's, 

 the medullary portion is dissolved out in the alcohols, leaving 

 only a thin base which will take certain stains (see charts) ; 

 but the cortical portion is preserved, usually as a ring of very 

 small droplets. 



The distal droplets were observed for indications of movement, 

 at various periods after the explantation of the egg string in 

 unstained media and in media stained with nile blue, toluidine 

 blue and methyl green respectively. Movement of the distal 

 granules was found to occur at all periods, and to occur so 

 rapidly during the first four or six hours after implantation, as 

 to be almost perceptible. These droplets, which were congre- 

 gated in the distal region of the follicle cell, were observed with 

 the low power to pass through the external membrane of the 

 egg string. Shortly after implantation, the passage occupied 

 on the average about three minutes; i.e., three minutes were 



