206 WAGENEE, ON GYRODACTYLUS ELEGAiNS. 



arise from both lobes of the ovary. It constitutes a mem- 

 branous canal which runs in close apposition with the wall of 

 the uterus, transversely from one lobe of the ovary to the other 

 in a straight line. The vas deferens as before said^ appears 

 to enter its upper wall. 



The uterus consists of an oval cavity surrounded with a 

 strong membrane. It lies between the limbs of the intestine, 

 which are in contact with its walls on all sides, except the in- 

 ferior, w^hich rests upon the oviduct. 



The size of the uterus depends entirely upon its contents. 

 If it contain a fully developed embryo, it distends the entire 

 circumference of the animal on both the dorsal and ventral 

 aspect ; and whilst pushing back the testis and ovary, it may 

 reach almost the whole length of the limbs of the intestine. 

 Immediately after the birth of an embryo it shrinks to 4 or 

 ■i- its former size, and remains distended with a clear fluid, 

 which may be said to be poured out suddenly into its cavity. 



This rapid emptying is accompanied with a simultaneous 

 shortening of the animal, in consequence of which also the 

 testes and ovary are made to occupy a rather higher position 

 than before. 



During the gradual distension of the uterus when pregnant, 

 the papil I af or m elevation through which the ovum and sper- 

 matozoa enter the uterine cavity, appears finally to be entirely 

 obliterated. After the birth this orifice is usually seen again to 

 project very prominently into the interior, though it some- 

 times happens that it remains invisible among the folds of the 

 uterus, so as to render its existence doubtful. 



But, however uncertain the existence of a permanent orifice 

 of this kind may be, that of an opening for the escape of the 

 young is still more uncertain. The spot at which the birth 

 of the embryo takes place is perfectly definite, close beneath 

 the penis -like organ afterwards to be described, but I have not 

 yet succeeded in detecting any special indication of an open- 

 ing at this point. 



Immediately after parturition, the integument is thrown 

 into folds, and a slight opacity of the organ ensues, which 

 renders it extremely difficult to detect the maternal orifice."^ 



The inner surface of the uterus is always covered with a 

 fine granular layer of irregular thickness, with which the 

 upper and lower points of the cavity are as it were, plugged. 

 In this layer may sometimes be seen minute cellseform bodies; 



* Mr. Bradley (1. c, p. 210), states that "while observing these animals 

 with Dr. Bowerbank, they saw the young creature free itself by tearing 

 through the parental envelope, and cout:aii:iug within itself tlie progeny of a 

 third generation." 



