706 THE ANATOMY OF BOTHRIOCEPHALUS LATUS. 



anterior portion, nor where the fertilising canal joins, so that the true 

 shape is rather that of a very bulging goblet, open superiorly. 



The Ovaries are, as in reality even Eschricht knew, and as is now 

 indubitably demonstrated, the so-called "lateral organs," two wing- 

 shaped structures of considerable size, which (Figs. 368 and 369) include 

 the shell-gland and the knotted-gland between them, and ascend on 

 the outside of the lower loops of the uterus. The lateral portions 

 extend to some distance beyond the median area, and the posterior 

 extremities can usually be traced close to the margin of the joint. 1 

 Like the ovaries of the Taeniadae, which they resemble in form, these 

 organs form a flat, glandular body, closely apposed to the musculature 

 of the ventral surface, and composed of numerous long, ramifying 

 caeca, spread out one beside another. This is best seen in injected 

 preparations, where the caeca are distinctly evident, in spite of 

 Moniez's denial. 2 The tubes have a thickness of about 0*03 to 

 0'04 mm., and extend in thick and short serpentine twists, so that they 

 appear as if sinuate. Especially in the upper half, where they lie 

 more closely and frequently overlap, the appearance of a composite 

 network is suggested. In such cases the course of the tubules can 

 rarely be followed for any distance, nor can their disposition be 

 definitely determined. We may, however, generally describe them as 

 radiating out in a fan-like fashion from above and from within, as is 

 especially corroborated by the fact that the lateral organs are con- 

 nected by a transverse bridge, extending in front of the lower end 

 of the receptaculum seminis. The structureless membrane which 

 bounds the tubules and this bridge externally is continued in 

 the middle line of the joint into the proper oviduct, which extends 

 backwards in a straight or slightly curved course, between the 

 receptaculum and the ventral musculature, increasing gradually in 

 width from O'Ol mm. to more than twice that, and finally opening, as 

 above mentioned, into the fertilising canal (Fig. 367). 



The ripe ova, which are met with especially in the bridge-like 

 connecting portion, appear as pale, membraneless balls, measuring 

 0*018 mm. in diameter, enclosing a vesicular nucleus of 0*009 mm., 

 within which a nucleolus of 0'003 mm. can be seen. They are 

 considerably smaller in the ovarian tubules, especially towards the 



1 I have never observed that, as stated by Sornmer and Landois (loc. tit., p. 20), 

 they extend beyond the posterior margin, as a flat ribbon-like appendage, reaching into the 

 next joint. Such an appearance was, indeed, occasionally seen, but a closer examination 

 showed that it was due to the overlapping of the margin of the joint. 



3 Moniez denies the existence of special ovarian tubules, interpreting the appearance as 

 strands of ova, embedded without envelope between the connective-tissue cells. The eggs 

 are said to be like those of the Cestodes generally, simply modified cells of the surrounding 

 tissue (loc. cit. t p. 156). 



