42 Dr. M. Barry on Prof. BischotFs History 



liquor of the copperas beds, and thus contaminating the sul- 

 phate of iron from which the oxide of iron employed by me 

 was obtained. Yours truly obliged, 



Romford, Dec. 18, 1843. J. DENHAM Smith. 



IX. Remarks on a Work by Prof. Bischoff of Heidelberg, 

 entitled " Entisoickelungsgeschichte des Kaninchen-Eies" 

 (History of the Development of the Ovum of the Rabbit), 

 1842. By Martin Bahry, M.D., F.R.S.S. L. and E. 

 HP HE following is the substance of notes written nine months 

 •*■ since, when I was reading the work of Prof. Bischoff. 

 Should the editors of the Philosophical Magazine consider 

 them suitable for insertion in their Journal, I shall feel obliged 

 by their allowing them to be published there. 

 19, X mo. (October) 1843. Martin Barry. 



Bischoff", Plates I. to VIII. inclusive.— There is certainly 

 some satisfaction in finding that observations recorded by my- 

 self two, three, and many of them four years since, in the 

 Philosophical Transactions*, have led to a repetition of the 

 same. But it is not very satisfactory to observe the mutilated 

 form in which my figures are made to reappear. This last 

 remark is intended to apply more particularly to figures re- 

 presenting the divisions which the essential portion of the 

 ovum undergoes in the Fallopian tube. 



Professor Bischoff seems to have adopted in part my mode 

 of obtaining ova (" Second Series," /. c, p. 365). Had he 

 fully done so, he would not have found it needful to raise the 

 ovum out of the oviduct with a needle ; a sort of manipulation 

 that it will not bear. And had he used the ring of putty I 

 recommended, the ova might have been preserved for days, 

 weeks, and even months ; instead of requiring to be kept from 

 drying up by the addition of foreign substances, which not 

 only diverts the attention of the observer, but completely 

 changes the appearance of the ova, and admits of their being 

 examined but for a very short time. The ovum fig. 16, it ap- 

 pears, had lain in water ! Nothing whatever should be added 

 to ova from the oviduct; nor is it advisable to make any addi- 

 tion to those from the uterus that have not attained a consi- 

 derable size. 



Nature is not represented in the figures Bischoff has given 

 of the so-called " yelk." This substance in the mammiferous 

 ovum, as I long since showed, corresponds to little more than 

 the " discus vitellinus " in the ovum of the Bird ; and, like it, 



• Researches in Embryology: First Series, Phil. Trans. 1838 j Second 

 Series, Phil. Trans. 1839; Third Series, Phil. Trans. 1840. 



