,338 Miscellaneous. 



The Coxiil Gland of the Scorpion and its Morphohxjical Relations 

 li'ith the Excretory Organs of the Crustacea*. Ey M. Paul Marchal. 



We know that the coxal gland of the Scorpion consists of two 

 portions, a medullary and a cortical substance. 



The structure of the medullary substance has not yet been eluci- 

 dated by authors. It presents two very distinct classes of lacunje 

 which have hitherto been confounded. The first of these are the 

 glandular lacunte : they are for the most part extremelv narrow, 

 and their lumen is often filled by glandular epithelium, which may 

 cause them to pass nnnoticed ; this epithelium presents a similar 

 aspect to that of the sac of the antennary gland of the Crustacea. 

 The second kind are the blood-lacunoB : they are wide and may be 

 distinguished at once from the former class bj^ the fact that tliey are 

 limited by a niembrana propria separating the glandular epithelium 

 from the sanguineous fluid, and a2)pearing in sections as a refringent 

 line ; moreover the blood-lacunte are often filled by a coagulum 

 presenting a punctate appearance. 



The glandular lacunae anastomose with one another so as to con- 

 stitute a spongy plexus, and open into a central lacuna much wider 

 than the others ; this larger lacuna plays the part of the ramified 

 sac of the marine Decapod Crustacea, and inosculates directly with 

 the long tube which constitutes the cortical substance. 



This communication between the medullary and the cortical sub- 

 stance, the existence of which is of the greatest interest from the 

 present point of view, had not hitherto been seen in the adult. It 

 presents a striking analogy to that between the sac and the labyrinth 

 of the antennary gland of the Crustacea. Around the orifice we 

 find the same clear columnar cells, swollen at their free extremity 

 and narrow at their base ; the passage between the epithelia of the 

 two portions which are so different from one another is ecjually 

 effected without a noticeable transition : immediately the orifice is 

 passed we meet with the cells which are striated in their basal 

 portion and are characteristic of the cortical substance. 



In the Crustacea, at least in the Decapods, which are the only 

 ones that I have studied, the sac is perfectly isolated, and it is always 

 possible to distingnish its epithelium from the connective tissue, 

 otherwise much reduced, which surrounds it. It is not the same 

 with the medullary substance of the coxal gland of the Scorpion : 

 at its periphery, and especially at the level of its anterior portion, 

 which is free and constitutes the hilum of the gland, the glandular 

 lacunje become purely virtual intercellular passages, and end by 

 being entirely filled up ; from this there results the formation of 



* The species wliicli was the subject of my ob^ervations was Scorpio 

 occitanus. For the specimens upon which this investigation was con- 

 ducted I am indebted to the kindness of Prof, de Lacaze-Duthiers, who 

 had them sent to me alive from the Arago I^aboratorv at Banyuls-sur- 

 Mer. 



