Coxal Glands o/* Scorpio. 55 



for my larger publication, it is necessary briefly to describe 

 them here, as their arrangement throws important light on 

 the morphology of the coxal gland in Scorpio. A long coiled 

 tube opens just behind the first pair of legs ; it runs backwards 

 among the muscles and nerves, free of connective tissue, then, 

 bending forward again, ends near its external opening. The 

 proximal end of this long duct is occasionally found expanded 

 into a spongy mass of branching and anastomosing tubules, 

 which join with the similar mass of tubules from the coxal 

 gland of the other side to form a barrier across the cephalo- 

 thorax. Through this spongy mass the blood, flowing back- 

 wards freely through the body, must filter. It is important 

 to bear in mind that these tubules are simply a development 

 of the ends of the ducts, and the whole may bs dissected out 

 free from the body without any entanglement of connective 

 tissue or blood-vessels, which latter do not exist in Gahodes. 



I am inclined to think that the histology of this gland is 

 not so simple as it appears at first sight, and that Macleod's 

 descri])tion* of it, though in the maiu correct, requn-es revision. 

 1 am not, therefore, as yet in a position to make any histolo- 

 gical comparisons between the coxal gland of Galeodes and 

 that of Scorpio. 



The gland opens in Scorpio^ not on the first leg, as in 

 Galeodes, but in exactly the spot where I have recently 

 shown t that the coxal gland of the Chernetidge opens, viz. on 

 the posterior face of the coxa of the third leg. In Scorpio 

 this posterior face of the coxa of the third leg is fused with 

 the anterior face of the coxa of the fourth leg. But this 

 fusion is so far incomplete as to form a channel close up 

 against the body ; this channel runs forward from the external 

 opening of the gland, so that the excretory matters Hud their 

 way to the exterior between the tips of the coxse of the third 

 and fourth pairs of legs close to the sternal plate. In serial 

 sections both the duct of the coxal gland, on its way to the 

 cliitinous channel thus formed by the fused coxa3, and the 

 chitinous channel itself arc very easy to find, and the fact that 

 they have been missed by former investigators \ can only be 

 exjdained by the frequent tearing of the sections by fragments 

 of hard chitin. 



Plate II. fig, 1 shows the chitinous channel in section, 

 while figs. 2 and o show the connexion of the duct of the 

 coxal gland willi this dannel. 



The duct of the gland is much coiled and forms a compact 



• Bull. Ac. Jiruxelles (3) t. viii., 1884. 

 t Jouru. Liiiii. Soc, Zoology (iu press). 

 \ Qimrt. Jouiu. Micr. Sci. xxiv. p. 164. 



