Miscellaneous. 371 



the sucking-disk. Muscular fibres are attached to the lower margin 

 of the sucking-cone and function as its retractors. Under the two 

 membranous sacs in the female lie the paired supporting plates, which 

 arc irregularly D-shaped. They meet at their upper ends, while the 

 lower ones diverge considerablj'. Beneath them lies a smaller j^air 

 of plates, united with them by a sort of hinge. On the protrusion 

 of the vagina, which is furnished with numerous chitinous folds, 

 the membranous sacs with the suckers and lateral supporting plates 

 move aside, while the posterior pair of plates flap backwards. By 

 these means a wide orifice for the passage of the vagina is produced, 

 and this, in consequence of the flexibility of the supporting plates 

 and their movable union, is further very dilatable. 



As male sexual organs w^e find two germ-glands, one of which is 

 situated behind the rectum in median line, and the other laterally. 

 Like the ovicells, the spermatoplasts are also developed from a 

 germ-magazine, the nuclei imbedded in a common plasmatic mass 

 becoming the starting-points of their formation. The seminal 

 corpuscles are very small, rounded cells. The vasa deferentla, Avhich 

 are densely packed with semen, are often much dilated and exhibit 

 irregular inflations. The delicate walls of the male sexual apparatus 

 and its great transparency are the reasons of its having hitherto 

 been quite unknown or interpreted in the most extraordinary 

 manner. As an accessory gland of the male sexual apparatus, we 

 have to indicate a large glandular tube running in a curve at the 

 margin of the abdomen, the efferent duct of which is dilated into a 

 reservoir into which the seminal ducts open. In sexually mature 

 animals this gland is greatly developed. Its secretory epithelium 

 consists of large indistinctly limited cells, which furnish a finely 

 granular secretion. As a copulatory organ, we find throughout a 

 greatly developed and strongly chitinized penis, the form of which 

 is very different in the difterent species, and which therefore 

 promises to furnish an important specific character. In the male 

 animal the outer supporting plates are amalgamated to form a pointed 

 bow, which, during copulation, is bent backward. Upon it lies the 

 penis, so that its free end is directed backward. The penis is a straight, 

 beak-like, or S-shaped channel, which closes at the apex into a 

 perfect tube. The bottom of the channel is perforated by a round 

 aperture, into which opens the ductus ejacidator'ms, which is partly 

 chitinized. 



The spaces between the organs are occupied by a connective tissue 

 (^corpus adiposum) formed by reticulated cells, passing on the one 

 side into the connective coating of the organs, and on the other 

 into the matrix of the chitinous envelope. Large quantities of fat 

 and carbonate of lime are deposited in these cells. The fatty cells 

 are distinguished by their large nuclei and the reticulate arrange- 

 ment of the plasma. — Anzeiger der Tc. A/cad. Wiss, in Wien, July 3, 

 1884, p. 134. 



