410 
W. N. F. WOODLAND. 
and maxillary glands can be distinguished : [a) The region of 
the end-sac, {h) the region of the kidney, and (c) the region 
of the duct. 
Histology of the End-sac. 
The region of the end-sac is distinguishable from the region 
of the gland proper by its relatively small size as compared 
with the kidney (though early in development they are equal 
Text-fig. 5, 
d.S-C. 
Cells of end-sac {End. S. C.) showing vacuoles (F.) and slightly 
granulated cells of kidney (M. C.) next end-sac (from longi- 
tudinal vertical section of adult Squilla). B.S. Very narrow 
hlood-sinus. ( X 810.) For other reference letters see id. 429. 
in size), by its spacious lumen (the invaginations of the end- 
sac wall being few in number and simple in character) and 
by the character of the cells. The position of the narrow 
communication between the lutnen of the end-sac and the 
kidney is very difficult to detect, since the opening is appa- 
rently not made evident by the presence of a couple or more 
of large trichterzellen,’^ such as those described by Allen 
( 1 ) in the maxillary gland of the larva of Palmmonetes and 
by Vejdovsky (22) in the antennal gland of Gammarus, and 
it is thus almost impossible to distinguish this narrow channel 
from the numerous other narrow channels penetrating the 
