SKCRKTORY PHENOMENA IN SILK GLAND. 



The cells of the anterior conducting portion are reduced in size, 

 being compressed but less elongated than cells of the reservoir. 

 The nuclei tend to be rounder and less branched, and the intima 

 can be definitely distinguished (Text-Fig. E, F). 



The tracheae that supply the posterior and middle regions 

 penetrate through the tunica propria into the substance of the 

 cell. It is significant that no intracellular tracheae are present 

 in the anterior conducting portion of the silk glands. 



COLOR REACTIONS OF SILK GLAND CELLS WITH VARIOUS STAINS AND FIXATIVES. 





Larval H. cunea furnished the entire supply of material with 

 the exception of a few glands from A patella americana and 

 Diacrisia virginica which were preserved in Bouin and DaFano 

 preparations for comparison. The age of the webworms could 

 not be determined as they had been actively secreting for some 

 time previous to collection as evidenced by the size of the webs. 

 An abundant supply of material was secured from bayberry 



