448 KOTIFEEA. 



female, and the bands which bring the penis forward, clearly show it to 

 be an extrusory organ, and to form a complete male apparatus. The 

 sperm-bag evidently contains active spermatozoa. 



(1160.) Although Mr. Dalrymple never had an opportunity of ob- 

 serving any action beyond the extrusion of the penis, Mr. Brightwell, of 

 Norwich*, has observed in seven different instances the direct copulation 

 of the two sexes clearly demonstrating this important fact, and thus 

 establishing the dioecious character of this remarkable family. 



(1161.) But there is another circumstance connected with these 

 Rotifers, almost without parallel in the animal creation. The male, as 

 has been said, possesses the same general figure as the female ; it has 

 also the contractile cloacal cavity, named by Mr. Dalrymple " the respi- 

 ratory sac," as well as the " water-system," furnished with the vibratory 

 or ciliated tags. It has also the ordinary rotiferous apparatus at the 

 head, through the agency of which its various movements of locomotion 

 are performed ; the red " eye-spot" likewise is distinct. It has, how- 

 ever, no mandibles, no pharynx, oesophagus, pancreatic glands, or stomach; 

 there appear to be no organs of deglutition, digestion, or assimilation ; 

 only, at the lower part of the animal, on the other side of and opposite 

 to the valvular opening, are three small oval bodies massed together, 

 having no communication by tube or otherwise, but fixed in their places 

 by short ligaments that may be rudiments of a stomach. 



(1162.) The difference of sex in these two forms, proceeding from the 

 eggs of the same individual, is plainly evidenced by the fact, not only 

 of the difference of structure, and the presence of active spermatozoa in 

 the male, but by the observed fact of the intromission of the male organ 

 into the vaginal canal of the female. That the male animal is produced 

 by the female, and developed within the ovisac in the same manner as 

 the female embryo, is also proved by many observations. The absence 

 of all organs for the sustentation of life by food leads to the belief that 

 it is created for a single purpose, and that its term of existence is very 

 short. In this respect it somewhat resembles the drone, or male bee, 

 whose utility seems to be confined to the impregnation of the perfect 

 female or queen. 



(1163.) That a single impregnation is sufficient for the production of 

 many young is proved by the female continuing to breed in water in 

 which no male can be discovered ; but young females so produced will 

 not go on to develope others unless a male be born amongst them. 



* Vide Ann. of Nat. Hist, for Sept. 1848. 



