874 DR. F. E. BEDDAKU ON 



often, perhaps generally, iudistinguisbable. But a granular 

 detritus often visible seems to me to indicate tbat their tendency 

 to disiippear is due to the fact tha,t they serve as nutriment for 

 the growing ovum. It may be noted, furthermore, that the egg- 

 shell in Eugonodceum is not nearly so broad as in Diplopylidium. 



A }-esemblance exists between the disposition of the ripe ova 

 in the present genus and that which characterizes Oochoristica. 

 I have re-examined examples of a species of Oochoristica which I 

 described lately to the Society as a near ally of, if not identical 

 with, Oochoristica ivage-iie^'i of Janicki*. In the course of my 

 account of that species I figured the scattered condition of the 

 ripe eggst, 'well known from the investigations of others to lie 

 one of the characters of this genus. I did not, however, atten)pt 

 any details, merely showing the inclusion of the ripe embiyos 

 e:ich in a sepa,rate chamber, and these scattered through the 

 general medullary parenchyma. I have now some details to add 

 to that account. The accompanying figure (text-fig. 149) shows a 

 part of a section through one of the last two proglottids of a 

 specimen of this species. It will be seen that the eggs are more 

 closely packed than in Eugonodceum. They are not, however, in 

 contact or enclosed in one cavity. This much concerning the 

 egg-sacs of Oochoristica is well known from the observations of 

 several writers previously to myself, e. g. Zschokke and v. Janicki. 

 But neither Zschokke + nor v. Janicki § give any detailed figures 

 in their memoii'S dealing with Oochoristica of the structui'e of the 

 scattered eggs or oncospheres, or of the spaces which they occupy 

 in the pai'enchyma. Zschokke describes the three membranes 

 which surround the hexacanth embryos, and observes of them 

 (the embryos) that they " liegen je einzeln in dichtgedriingten, 

 rundlichen, kapselartigen Follikeln des Parenchyms." Cohn |i 

 figures the crowded embryos with their three surrounding mem- 

 branes entirely filling the proglottids at the ei:id of the body ; 

 but he also does not enter into various histological points which 

 are, as I think, of interest in comparing the scattered egg-capsxdes 

 of Oochoristica with those of other tapeworms. 



In longitudinal sections of the entire ripe proglottid these egg- 

 capsules are seen to be circular or more oval in contour, and to 

 be larger or smaller in size with no regularity of aiTangement. 

 The differences of size correspond as I think partly at least to 

 differences of age. The more or less circular contour may have 

 a relation to the plaiae of the sections. Contrary to the obser- 

 vations of Zschokke and Cohn upon the species studied by 

 themselves, I can see but one egg-membrane which occupies all 

 the available space in the egg-follicle, Y. Janicki gives no 



* Zeitschr. wiss. Zool. Ixxxi. 1906, p. 533. 



t P.Z.S. 1911, p. 633, text-fis'. 150. 



I "Das Genus Oochoristica Liihe," Zeitschr. wiss. Zool. Ixxxiii. 1905, p. 63. 

 § Loc. cit. 



II Arch. f. Nature-. 1903. 



