INDEPENDENTLY OF SEXUAL INTERCOURSE. 47 



prove that in these animals, as in the lower classes, ova are discharged 

 from the ovaries independently of the influence of the male. 



Several experimenters Dr, Blundell,* Hausmann,| and Bischoff,! have 

 observed that, when one oviduct, or one half of the uterus has been tied 

 or divided in an animal previous to coitus, although foetuses are sub- 

 sequently met with only on that side on which the passage to and from 

 the ovary remains free, yet ruptured ovarian vesicles, or corpora lutea, are 

 found in loth ovaries. And Dr. Blundell has shewn that the result, as 

 regards the ovaries, is the same, if the vagina be divided near to the mouth 

 of the uterus, so as completely to interrupt its canals, and to prevent the 

 seminal fluid from reaching even the uterus, although, of course, no 

 embryos are produced in this case. These experiments proved that 

 Graafian follicles burst independently of the contact of the seminal fluid ; 

 but still they left room for the objection that the rupture of the follicles 

 might have been caused by the excitement attending sexual connection. 

 This objection, however, does not apply to the fact vouched for by many 

 writers of high authority Cruikshank, SirE. Home, Paterson,|| Haus- 

 mann,H Raciborski,** and Bischoff, and now almost universally admitted, 

 that if mammiferous, which have been kept separate from the male, be 

 killed during the period of heat, the Graafian follicles will be found either 

 turgid and extremely vascular, or already burst and in various stages 

 of conversion into corpora lutea. 



All the foregoing observations were, however, defective inasmuch as they 

 did not demonstrate the ova which had escaped from the ovaries. This 

 deficient link in the chain of evidence has been supplied by M. Bischoff 

 and M. Raciborski. The following is an abridged account of one of M. 

 BischofTs important observations, ft On the 18th and 19th of December, 

 1843, he remarked that a large bitch in his possession commenced to be 

 in heat. He kept her closely shut up, and on the 23rd (having previously, 

 on the 21st, ascertained that she was disposed to receive the male, though 

 he did not permit coitus to take place) he cut out the left ovary and Fallo- 

 pian tube, arid closed the wound by suture. On examining the ovary he 

 found that no Graafian follicles had yet opened, though four of them were 

 much swollen, undergoing the changes preparatory to the discharge of the 

 ova. Five days later he killed the animal and he now found that rupture 

 of the follicles in the remaining right ovary had taken place. Four 

 corpora lutea were well developed. 



Bischoff now sought for the ova. Having carefully dissected the 



* Medico-Chirurgical Transactions, vol. x. p. 254. Experiments on Rabbits. 



t Ueber die Zeugung des wahren Weiblichen Eies. Hannover, 1840, p. 93. 



t Beweis, p. 10-17. $ Philos. Transact. 1817, 1819. 



|| Ed. Med. and Surg. Journal, vol. liii. p. 64. 



TI Ueber die Zeugung des wahren Weiblichen Eies. p. 94, 95, and 96. 



** Op. Citat. p. 376, et seq. tt Beweis, p. 28. 



