206 Annals Entomological Society of America [Vol. IX, 



Just beneath the reservoir hes the pore canal ( pc) which is 

 usually narrower than the diameter of the reservoir. 



Lying in the hypodermis just beneath the pore canal lies 

 the large gland cell {glc). On account of its size and the way 

 the hypodermal wall (Figs. 20 and 21) bulges around it, this 

 cell is much more conspicuous than the hypodermal cells. In 

 fact the walls of the hypodermal cells can not be recognized but 

 their nuclei (Fig. 20, hnuc) are distinct. The nuclei of the 

 gland cells (Fig. 9, nuc) are larger than those of hypodermal 

 cells. They are usually round while those of the hypodermal 

 cells are oblong. They generally lie in the broader ends of the 

 cells. Their nucleoli (nucl) are always distinct. The cytoplasm 

 {cyt) is more or less granular. Lying either near the center or 

 in the narrower end of the cell there is a transparent, round 

 area, the ampulla {am), which is usually larger than the nucleus. 

 The ampulla appears to contain radial lines, but on account of 

 the small size of the cells, these lines are almost indiscernible. 

 At the center of each ampulla is always distinctly seen the free 

 end of the conducting tube (c) whose walls at the free end are 

 darker than elsewhere. Sometimes a dark circle is seen at the 

 center of the ampulla, showing that the conducting tube has 

 been cut in two. This fact shows that the tube is really hollow 

 and is not solid. The conducting tube leads from the center of 

 the ampulla through the pore canal to the reservoir where its 

 walls unite Vv^ith the walls of the mouth of the reservoir. 



The gland cells vary considerably in size. The largest ones 

 (Fig. IS, glc) are associated with the groups of pores at the 

 distal end of the femur. Those in the elytra are about as large 

 as those widely distributed in the legs. 



The reservoirs and pore canals (Figs. 10 and 11) also vary 

 considerably. The reservoirs in the femur near the articular 

 membrane (Fig. 19) are the largest. The pore canals and con- 

 ducting tubes depend in length on the thickness of the chitin 

 (Figs. 10 and 11) which varies much. 



In order to ascertain if the efferent and conducting tubes 

 are chitinous, fresh material containing the femoro-tibial artic- 

 ulations was treated in caustic potash four hours. A study of 

 the sections made from the material thus treated showed that 

 these tubes are composed of chitin (Fig. 12, e and'c). 



