ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 403 



7- Platyhelminthes. 



Leuckart's 'Die Parasiten des Menschen.'* — Prof. R. Leuckart has 

 published a further instalment of the second edition of his classical work 

 on human parasites ; in this the development and structure of Bothriocephalus 

 continues to be described. In addition to the well-known B. latus there are 

 accounts of B. cordatm and B. liguhides ( = Ligula mansoni Cobbold). In 

 an appendix of additions and corrections the author brings this volume, the 

 issue of which began in 1879, up to date, giving interesting information 

 regarding the increase in our knowledge of parasitic Protozoa, and a 

 resume of the advances in the history of the Cestoda. The structure and 

 life-history of the Trematoda is commenced in the first few sheets of the 

 next part. So far as Protozoa to Cestoda are concerned the work is now 

 accessible to those who read only English. f 



Anatomy of Bilharzia.J — M. J. Chatin states that the fine spines 

 found on the integument of Bilharzia are more numerous and better deve- 

 loped in the female than in the male ; these spines have, no doubt, a greater 

 morphological value than has ordinarily been attributed to them, for they 

 must play a certain part in the lesions of the capillaries which are caused 

 by the presence of these parasites. The muscular body-wall is only 

 moderately thick as compared with that of other Trematodes. The 

 oesophagus, which is at first narrowed, widens out, and becomes curved ; 

 where the two limbs of the stomach join there is a small median caecum, 

 which ought properly to have the name of intestine ; its slight development, 

 and its variation in sexes and individuals show that it is of no great value 

 physiologically ; unlike what happens in most of its allies, Bilharzia has 

 the enteric miiscular layers poorly developed, even in the region of the 

 pharyngeal bulb. As M. Chatin has been able to detect in some examples of 

 Distomum lanceolatum a tendency to the approximation of the two caeca he 

 thinks that Bilharzia may be allied to the typical genus of the Trematoda. 

 An account of the excretory and generative apparatus is reserved for 

 another communication. 



Excretory and Reproductive Systems of Billiarzia.§ — M. J. Chatin 

 has made a careful study of the excretory apparatus and reproductive 

 organs of Bilharzia, in regard to which our knowledge has been hitherto 

 almost confined to the original, and apparently inexact description of Bilharz. 



(a) The well-developed excretory system has a posterior contractile 

 orifice, into which there opens an elongated reservoir, receiving the two 

 lateral and single median vessels. The main vessels, which are lined by 

 a definite membrane, divide and ramify, with a marked reduction in the 

 male. 



(6) When macerated in dilute alcohol, the testes separate from one 

 another, and are seen peripherally to consist of fine tubules continued into 

 the seminal ducts. These extend to the vas deferens, which before passing 

 into the " gyngecophorous canal "^^dilates into a simple prostatic, certainly 

 not penial sac. 



(c) The small, lateral ovary of this remarkable dioecious Trematode is 

 masked by a portion of the uterus, is slightly four-lobed, and connected by 

 a short oviduct with the junction of the albumen duct and the stalk of the 

 shell-gland, (d) The albumen glands form numerous lateral lobes com- 



* 'Die Parasiten des Menschen,' Bd. 1. Abth. 1, pp. 855-1000, title-page and xxxi. 

 pp. ; Bd. i. Abth. 2, pp. 1-96. 



t 'The Parasites of Man,' translated by W. E. Hoyle, 8vo, Edinburgh, 1886, 

 771 pp. and 40i figs. 



X Comptes Rendus, civ. (1887) pp. 595-7. § Ibid., pp. 1003-6. 



