Coxal glands of the Arachnids. 275 



filled with granular matter ; the lobes of the saccule appearing to 

 be empty. 



Fig. 29. From a section through a more external part of the eland. 

 250:1. ^ 



The short vesicle (F) opens above into the saccule (S) with 

 its inhanging glomeruli {OLE). Below the exit tubule is 

 indicated by {ET in brackets). 



Probably that part of the saccule into which the vesicle opens, 

 represents the remains of the internal tubule, the true saccule 

 being that part which lies on the right, immediately below the 

 coecum. 



Fig. 29a. From a section a little more internal to 29. 100: 1. 



A small portion of the vesicle can still be seen opening widely 

 into the saccule. The saccule itself now extends posteriorly for 

 a considerable distance, its posterior portion being probably 

 chiefly if not entirely composed of what were originally the 

 tubules of the labyrinth. 



Plate 25. 



Fig. 29b. From a section still more internal. 100: 1. 



Showing the relation of the saccule to the endosternite. 

 Probably all of the saccule here visible represents the original 

 labyi-inth tubules, since the saccule itself in the Theraphosids and 

 in group 1 of the Araneae vei-ae does not extend so far inter- 

 nally. 



{CUT, CIV) Coeca of appendages. Each coecum loops round 

 over and external to the coxal gland and enters the appendage. 

 (P) Loops of the poison gland which in Filistata is very extensive. 

 (BLS) Blood sinus from which glomeruli hang into the saccule. 



Fig. 30. Lntrodedus madans (Theridiid). Adult. Sagittal. 250 : 1. 

 Views comparable with that of 29, but showing in addition 

 the exit tubule {ET) and outlet {()). The walls of the vesicle 

 are here surrounded by finely striated longitudinal muscles. 



Plate 26. 



Fig. 30a see Fig. 30. 



Fig. 31. Epeira iyifoHum (Epeirid). Adult. Sagittal. 100:1. 



May be compared with photograph 30. The vesicle is filled 



with excretory products. 



Fig. 32. Tkeridium tepidariorum (Theridiid). Adult. Sagittal. 100 : 1. 



The details of the saccule are not well shown, but the vesicle, 



opening widely into it and the exit tubule are clearly marked. 



