io6 



NEEDHAM. 



[VOL. I. 



ST- 



x 220. EP, the epithelial layer ; 



ST, the striated border; N, a 



nidus; CAT, space filled by the 



layer of circular muscles; LAf, 

 longitudinal muscle fibers. De- 

 tails of the muscles are omitted 



from all the figures. 



it, or to dissociate them satisfactorily. At B in Figs. 3 and 4 



are the bases at least of some of them. 1 



Fig. 4 shows the continuation of this process of accumulation 



as found in a nymph that had been kept in a bare dish of water 



for two months. I was expecting to 

 find degeneration in the cells of this 

 preparation, but found instead the re- 

 markable condition of things shown in 

 the figure. The cells appeared per- 

 fectly healthy. The nidi were full of 

 cells. The striated border had disap- 

 peared, or was only faintly discernible 

 in the bottom of the now lumen-like 

 depressions opposite the nidi. The 

 epithelium was about three times its 

 original thickness, and the upper two- 

 thirds of it consisted of the wedge- 

 shaped apices of granular cells crowded 

 above the original level. 

 Figs. 2, 3, and 4 are from nymphs of the same age and size 



taken together and kept under identical 



conditions except as stated above. They 



are therefore strictly comparable, and to- 

 gether might furnish a morphologist good 



reasons for taking physiological conditions 



into account. 



II. THE DISCHARGE OF THE 

 DIGESTIVE SECRETION. 



After food is eaten it is perhaps an hour 

 before it makes its appearance in the ven- 

 triculus. As soon as it enters, the more F IG. 3 . -Resting epithelium 

 turgid of the epithelial cells begin to be after two weeks ' fastin ^ * 



220 : parts as in Fig. 2. At B 



discharged bodily in whole or in a large are the bases of ceils to which 



.,, . T-,, ,. , , . the wedge-shaped apices op- 



part to mix with it. This discharge begins posite are believed to belong . 



1 There is no supporting connective tissue between these cells. In CoryJalis 

 cornuta L. the basement membrane is produced upward in anastomosing plates 

 with which all the cells are in evident contact. 



