Coxal glands of the Arachnids. 273 



spending to the external tubule in the Dysderids. The internal 

 wall of the tubule is irregular in outline and the tubule seems 

 to have been formed by a breaking through of adjacent labyrinth 

 coils. The return tubule {RT) running forward to the exit lies 

 partly above and partly below, and corresponds to the internal 

 or return tubule of the Dysderids and hunting spiders. It also 

 is irregular in outline. The approximate position of the exit 

 tubule is indicated by {ET) in brackets. 



Plate 20. 



Fig. 20. Dugesiella hentzii. Adult. 400 : 1. 



A portion of the coxal gland three days after inoculation 

 with carmine. The lining cells of the saccule are swollen, and 

 are filled with minute granules. The nuclei are stained with 

 hematoxylin and there is a counterstain of orange, but the granules 

 in the cells represent the red carmine granules. No such granules 

 can be seen in the labyrinth cells. 



Araneae verae. 



Group 1 . 



Fig. 21. Loxosceles rufescens (Sicariid). Adult. Trans. 200 : 1. 



Transverse section at about the middle of the coxal gland. LET 

 is the external tubule leading posteriorly from the saccule, and 

 LIT the internal tubule, close to the endosternite, leading an- 

 teriorly towards the exit tubule. The cell surfaces are worn down 

 to the nuclei but the striatiou shows no evidence of deterioration. 



Plate 21. 



Fig. 22. Dijsdera (sp.?) (Dysderid). Immature. Trans. 400:1. 



Transverse section about the middle of the coxal gland. 

 Compare with 21. 



Fig. 23. Dysdera crocata. Adult. Trans. 250: 1. 



Transverse section across the coxal gland at the point where 

 the saccule (*S') passes into the external tubule {LET). 



Fig. 24. Loxosceles rufescens. Adult. Trans 250 : 1. 



Transverse section across the anterior part of the coxal gland, 

 showing the saccule and internal tubule (GLR) is a large 

 glomerulus with a mass of blood cells. The nuclei of the blood 

 cells are oval or flattened; those of the saccule are spherical. 

 The diagram explains better than a description how it comes 

 about that the internal tubule of the labyrinth appears to be 

 double. 



