Coxal glands of the Arachuids. 253 



in the solifugae and scorpions can be considered as tlie remnants 

 of the coelom or not, and comes to the conclusion that they cannot 

 be so considered, but are simply modifications of the ordinary laby- 

 rinth tubule; also a mistaken view in all probability. 



At a point in close proximity to the saccule, the sac of the 

 labyrinth [SL) passes abruptly into the second part of the labyrinth 

 (CL) (photos 36, 36 a) which is typical in every respect. We find 

 here the coiled tubules lined with cells having the typical striated 

 base upon, or just w^ithin, which the nuclei are placed. From its 

 opening' from the secreting sac (diagram D, Galeodidae) the tubule 

 runs posteriorly as far as the sixth appendage, w^here, after forming 

 a few coils, it turns and runs anteriorly again to the main part of 

 the gland. Here, after coiling a little upon itself, it passes on 

 anteriorly as an almost straight tubule to the base of the second 

 appendage. 



As the exit tubule {ET) it then extends forwards along the 

 dorsal side of the coxal joint of the second appendage just under- 

 neath the chitinous tegument its walls becoming muscular (photo 38), 

 to its outlet at a point about opposite the front of the* median eyes, 

 and just below the base of the chelicera. The tubule here turns a 

 little inwards and terminates in a strong chitinous ring with a 

 minute orifice in its center, which acts as a nozzle {NZ) (photos 38, 

 38 a, 38 b). 



The nozzle lies in a groove, formed by two flaps of the chitin- 

 ous integument, which extend as a sheath {LE) for some distance 

 further forwards and provide a kind of conduit for the fluid ejected 

 from the nozzle (photo 40, 40 a). 



The second appendage (palp) is always directed forward and 

 the dorsal aspect of its coxal joint works under, and rubs against 

 the ventral surface of the enormously developed first appendage 

 (chelicera), so that this extension of the exit tubule and the chitin- 

 ous sheath beyond its outlet run anteriorly and finally a little 

 inwards. 



Since the natural position of the outlet would be at the base 

 of the coxal joint of the appendage it seems probable that this 

 anterior extension of the tubule along the coxa, with its muscular 

 w^alls and nozzle like outlet, must be a secondary development de- 

 signed to serve a special purpose, and in fact the outlet is situated 

 at a point from which fluid ejected with some force would be pro- 



