176 REPRESENTATION OF THE 



111 some of the latter the animal certainly has more the ap- 

 pearance of a mere detached organ, being, by defect of the 

 apparatus of alimentation and locomotion, reduced to the 

 condition of a minute spermatic cyst. Yet its status as a 

 distinct animal is established by its having the same origin 

 from the impregnated ovum, and passing through the same 

 intermediate larva form, as its more highly organized mate ; 

 as well as by the gradation through different species from 

 tliis extreme of degradation up to the entire fulness of the 

 type of the order.* 



In the structures now contrasted — the so-called parasitic 

 males, on the one hand, which have just been noticed, and 

 the large Medusse on the other — we have examples of the 

 two extremes of organization ; in the one case we have a 

 member, organized above par, so as to simulate a complete 



would seem that an absence of alimentary organs is a general feature in 

 the males of the Rotifera — he has found it in all he has ascertained, or 

 has reason to believe, to stand in this relation. The first observations 

 were those made on the genus Asplanchna. See Brightwell, in Ann. 

 Nat. Hist., N.S., II., 154; Dalrymple PhU. Trans., 1849, p. 340 ; and 

 Gosse An. Nat. Hist., N.S., 2d Ser., 18. 



* In Ihla there is a certain amount of embryonic or rudimentary or- 

 ganization ; some species of Scalpellum have the ordinary structure of 

 the class, but others are extremely rudimentary, and when mature " may 

 be said to be essentially mere bags of spermatozoa," having no mouth, 

 or other viscera, but those of reproduction. The males of Crypto2:>Malxis 

 and AlciiJpe are, if possible, still more rudimentary, for they are reduced 

 to an outer envelope, a single eye, a spermatic gland and vesicle, and an 

 intromittent organ eight or nine times their own length, coiled up Kke a 

 great worm ; there is neither mouth, stomach, throat, abdomen, nor 

 cirri. All these rudimentary males are microscopic, sometimes not ex- 

 ceeding the size of one of the ova which they have to impregnate. They 

 are in some cases attached in numbers at the same time — as many as 14 

 in Alcippe — and their existence being transitory, fresh relays attach 

 themselves as the ova become ready successively for impregnation. See 

 Darwin's Cirripedia (Ray Soc), I., 291, II., 26, 561, 586 ; Carpenter's 

 Comparative Physiology, 4th Ed., p. 606. Some prior observations of 

 Mr. Goodsir of a similar import will be found in the Edinb. Philos. 

 Journal for 1843, v. 83, XXXV. 



