Coxal glands of the Arachnids. 241 



in the hig-her spiders the excretory products are utilized for silk 

 production, and the coxal glands therefore deg-enerate. The suggestion 

 is a good one so far as excretion hy the labyrinth is concerned, 

 but in all spiders excretion by the saccule seems as if it should 

 go on as usual, so far as one can judge by its histological appearance. 

 Both KowALEvsKT and Bruntz have demonstrated that in scorpions 

 and certain other Arthropods, some (colored) substances injected are 

 eliminated by the saccule and others by the labyrinth, but neither 

 of them appear to have recognised any excretion (of color) by the 

 spinning glands after injection into spiders. But the actual number 

 of spiders so treated up to the present time is very limited. 



A. Theraphosids. Specimens sectioned and studied. 



Genus ? Biskra. Immature. 



„ Avicularia So. America. Adults and young just 



leaving cocoon. 

 „ Eurypehnavagansa.ndL Panama. Adults and young with mother 



rusticum and from cocoon. 



„ Bugesiella Jientm Texas. (Peteunkevitch. Fixed in 



sublimate.) 

 „ Hapdlopus pentaloris, Colombia. Immature. 

 „ Ischnothele Colombia. Immature. 



Neodeniza mexicana Panama. 



Ischnocolus Arizona. 



Atyptis affinis Europe (ale. spec. S.). 



The coxal gland is elongated as in the Pedipalps; the coils of 

 the labyrinth extending forward to the base of the second appen- 

 dage, and posteriorly almost to the posterior aspect of the sixth 

 appendage. The organ runs continuously throughout, just above and 

 external to the endosternite on either side. The labyrinth is so 

 complicated that it has not been possible to follow up the tubules 

 and determine if there are two distinct systems of labyrinth, one 

 for each saccule and outlet, but I am inclined to think not, and to 

 consider the labyrinth as a system of tubules common to the two 

 saccules and outlets. 



The two saccules however are clearly distinct as can be best 

 determined by dorso-ventral (frontal) sections. In such sections, 

 tracing from the dorsum downwards, at about the middle of the 

 cephalothorax the labyrinth {CL) can be seen extending continu- 



