NEW AVIAN TAPEWORM. 205 



the individual testes and tlie general medullary paienchyma is 

 strikingly obvious in such sections, inasmuch as the whole area 

 can be seen in a single section extending from one side of the 

 body to the other. Such sections also show particularly well the 

 fact that the testes extend rather beyond the large ventral water 

 vascular vessel on the fore side, where, indeed, they occasionally 

 nearly touch the outer skin. The extension is not quite so great 

 on the opposite side, though the mass of testes usually bulges into 

 the vessel, and, as already mentioned, presents very much the 

 appearance of lying in it. It is to be noticed also that in these 

 lateral extensions of the testes the whole mass gets very much 

 wider from back to front, the testes being three or four deep. 

 These outgrowths intrench upon the area occupied by the coils of 

 the vas deferens, and push laterally and flatten out that coil. 

 The extension of this testicular mass laterally is highly suggestive 

 of its being a single organ growing as a whole and not merely an 

 association of separate and quite individualized testes. The inter- 

 stitial substance which divides the testes presents the appearance 

 in the direction of its fibrils of having flowed laterally, carrying 

 with it the enclosed testes. Multiplying the 30 or so testes 

 which are visible in a horizontal section by the 6 oi- 7 which are 

 visible in ;i sagittal section, we get a total of 200 or so, which may 

 be slightly increased to include the testes found in the lateral 

 extensions of the testicular area just lefeired to. 



The ovaries are very obvious in the segments where they occur; 

 but they disappear early in the strobila and are represented 

 thenceforward by mere vestiges. The ovaries are to the fore side 

 of the segment and closer to that margin of the strobila than the 

 vitelline glnnd, to which, however, they are closely contiguous. 

 They commence on the level of the receptaculum and lie on both 

 dorsal and ventral sides of that portion of the oviducal tube, 

 hence getting a double character — the ventral half (or more 

 ventral ovary, if we speak of two) is considerably the larger. 

 They lie posteriorly in the segment, but between the testes and 

 the uterus. They by no means occupy the whole breadth of the 

 medullary parenchyma in a sagittal section, as do the testes when 

 fully developed. 



The cloaca genitalis opens on to the exterior directly. There 

 is no papilla-like process bearing a genital orifice. As already 

 mentioned, the pores are irregulai-ly alternate in position, and I 

 have seen as many as six consecutive pores on the same side of 

 the body. The cavity of this conjoined region of the genital ducts 

 is rather wide and of some length ; the lumen is slit-like to 

 circvdar, but the walls never seem to be crumpled so as to give a 

 star-like appearance to the lumen. The cavity is lined by a vexy 

 thick layer of cuticle which stains very deeply in carmine. The 

 walls of the cloaca genitalis contain at some little distance from 

 the chitinous lining a sheath of loosely packed lai-ge muscle-fibres, 

 which completely encircle the tube and run in a lono-itudinal 

 direction. The fibres form several layers when seen in transverse 



