428 APPENDIX. 



above described * but when burst, the lymph and blood in an 

 altered state remain for a while in the form of a corpus luteum, 

 which may thus be compared to the hard base of an abscess 

 evacuated prematurely. Though true corpora lutea y there is 

 reason to believe, are formed only after coitus, impregnation 

 may take place without the formation of a corpus luteum. 

 How is this ? The explanation which might be offered of such 

 rare cases is this : Coitus may have chanced to take place at 

 the very time when a Graafian follicle, having become mature, 

 had spontaneously given way and expelled the ovum. No 

 congestion, exudation, and extravasation, would in this case 

 take place, but the part would quickly close and cicatrise. 

 4. Lastly, what explanation can be given of the origin of false 

 corpora lutea ? To this it might be answered, that from some 

 circumstance or other, effusion of blood takes place into the 

 interior of a Graafian follicle, perhaps on the point of bursting 

 spontaneously. This blood coagulates and remains filling and 

 distending the Graafian follicle, even although its walls may 

 have subsequently given way. But besides this effusion of 

 blood, an exudation of lymph takes place on the inner surface 

 of the walls of the Graafian follicle, in consequence of the irri- 

 tation produced, which, becoming organised, presents the same 

 yellow appearance as the substance of the true corpus luteum 

 formed outside the walls of the Graafian follicle. 



" In conclusion, I would remark, that, though physiologically 

 one may be permitted to speculate, as I have done, on the 

 relation between the occurrence of corpora lutea in the ovaries 

 and preceding coitus, it would be rash and unwarrantable in 

 any one to pronounce positively from the occurrence of a 

 corpus luteum in the ovaries that coitus had taken place. The 

 discovery of an ovum in the uterus, in process of development, 

 could alone, in the present state of knowledge, warrant such an 

 affirmation in a court of law. But, on the other hand, the 

 absence of a corpus luteum could not warrant the affirmation 

 that coitus had not taken place." 



§4. 



Development of the Teeth. — In an Essay on this subject in 

 the ' Quarterly Journal of Microscopical Science/ for April, 

 1853, we have taken a very different view from that advocated 



