706 mh. r. i:. i:i;i>i>\iiP ox tiij; [Dec. 17. 



oval-contoured diverticulum by means of a short and slender duct. 

 The latter, as is the rule with the diverticula of the Megascolicida*, 

 is tilled with a felted mass of spermatozoa. In no one instance 

 out of the many spermathecae which I have examined did I Hud 

 an entire absence of spermatophores ; but they were fully developed 

 in but few. The spermatophore of this worm lias a remarkable 

 form and mode of origin. The muscular duct of t In- spermatheca 

 was sometimes quite empty of any traces of a spermatophore. In 

 other specimens it was occupied (see text-fig. 92) by a body of 

 apparently chitinous structure and of a trumpet-shape, a< is shown 

 in the figure referred to. This body contains a lumen which 

 appears to be open at both ends. The upper end is like the mouth 

 of a trumpet, and is wider than the section which follows. It is 

 closely applied to the walls of the spermatheca, and its shape is 

 indeed an expression of this close contact. The trumpet-shaped 

 extremity corresponds to the widening of the duct to form the 

 thin-walled pouch of the spermatheca ; the edges of the sperma- 

 tophore are here curved outwards, and again slightly downwards. 

 At the opposite end there is no diminution of calibre until the 

 very end. At Ibis extremity the spermatophore ends before the 

 end of the spermatheca] duct in which it lies, and apparently h\ 

 an open mouth, as is figured by Michaelsen in the spermatophore 

 of Benhamia monticola. A closer examination of this trumpet - 

 shaped or quiver-shaped tube, by compression in glycerine, and by 

 sections (text-fig. !>4, p. 7'»7), enables the structure to be seen. 

 It is hardly at all stained by the carmine which was used ; a fact 

 which shows its likeness to chitin, of which I cannot doubt that 

 it is formed. It has, however, a definite and characteristic minute 

 structure. The walls are very thick in the shaft region, and thin 

 out considerably as the case widens out to form the trumpet- 

 shaped mouth with its slightly-recurved edges. The thick part of the 

 walls consists of two layers. The inner layer which borders upon 

 the lumen appears to be quite structureless, and it resembles 

 exactly the thick chitinous lining of the gizzard of earthworms. 

 Outside of this the spermatophoral walls are composed of a 

 parallel series of oblong pieces closely adpressed, but tending to 

 come apart in sections. These correspond, 1 take it, to the 

 individual cells of the lining membrane of the spermathecal duct. 

 The separation of the individual contributions of these cells may 

 ho a mark of fatigue, so to speak, on the part of the cells after 

 throwing out the abundant matter required to form the inner half 

 of the spermatophoral case. They are an indication that the 

 secretion of chitinous matter is getting less active. "When the 

 spermatophore is viewed from the outside, these brick-like con- 

 stituents form a kind of mosaic upon its surface. I have found 

 no variation in the form of this half of the spermatophore; 

 indeed the identical form of the spermatheca leaves no room for 

 variation. It must be noted that there can be no doubt that this 

 chitinous case is formed where it is found : it is altogether too 

 large to have been produced by the thin ducts of the spermiducal 



