Dr Martin Barry's Researches in Embryology. 37 



miferous ovum, — both of which I published in March 1839, — 

 received immediate confirmation. All the others were denied. 

 Yet since then they have all, without exception, been abun- 

 dantly confirmed. Some of these facts, however, remained un- 

 acknowledged for so many years, that the original record of 

 them was forgotten. These have proclaimed themselves 

 in ova of some of the lower animals, and observers are pub- 

 lishing them as quite new, though really no more than con- 

 firmations of facts first observed in the mammiferous ovum, and 

 recorded inthe Philosophical Transactions many years before. 



Up to the period when I communicated to the Royal Society 

 the second series of those Researches, entire ignorance of the 

 time post co'itum when the ovum leaves the ovary had so com- 

 pletely prevented the obtaining of ova from the Fallopian 

 tube, that nothing was known of the essential part of the 

 mammiferous ovum between its expulsion from that organ, 

 and a comparatively advanced condition of it in the uterus. 

 By a determination of that time the hindrance in question was 

 removed ; it was thus made comparatively easy to procure ova 

 from the Fallopian tube, in one of the Mammalia at least — - 

 the Rabbit. And very soon afterwards a work by Professor 

 Bischoff appeared in Germany on the mammiferous ovum, ac- 

 knowledging that Barry seemed to have been right in his an- 

 nouncement that the time post co'itum when the ovum of the 

 Rabbit usually leaves the ovary is about nine or ten hours.* 



To determine the time in question, was a task requiring a 

 great deal of patience, and attended with difficulties of no 

 common kind. But in the course of that inquiry I became ac- 

 quainted with the fact that there was another period also in 

 the existence of the mammiferous ovum regarding which 

 nothing whatever had been ascertained, — the period interven- 

 ing between the coitus and the expulsion of the ovum from 

 the ovary. I saw changes then taking place in the ovarian 

 ovum, without a knowledge of which it is impossible to under- 

 stand the ovum in any of its future phases. And it is mainly 

 to what was noticed by myself during the inquiry now referred 



* Or words to this effect. I write from a part of the country where the hook 

 is not obtainable. 



