■12 Dr Martin Barry's Researches in Embryology. 



zoon and the germinal spot is not essential in ova where the 

 yelk enters largely into the formation of the new being. In 

 the mammiferous ovum, the hyaline centre of the germinal 

 spot, and the hyaline in the head-like extremity of the sper- 

 matozoon are both to be considered nucleoli, a mixing or 

 combination of which it appears to me yields the substance 

 out of which is formed the new being ; and to this mixing I 

 apprehend is to be attributed the resemblance between the 

 offspring and both its parents.* 



Keber justly deprecates theory when it is attempted there- 

 with to make up deficiencies left by superficial investigation, 

 and gives examples of it in two papers recently published in 

 Germany on this very subject, shewing the conclusions they 

 contain to be valueless, annihilated as they are by positive 

 observation. The author of one of those two papers is Bis- 

 chofF.t that of the other, Kblliker.J 



I fully adhere to what I first published in 1839, and again 

 recorded as established and extended by means of higher 

 magnifying powers in 1840, that in the mammiferous ovum, 

 the mulberry-like body into which the fecundated germinal 

 spot has divided, contains a cell larger than the rest — a sort 

 of queen-bee in the hive ; and that the embryo arises out of 

 the nucleus of this cell, in the form at first of the so-called 

 " primitive trace," and " chorda dorsalis." 



This origin out of the nucleus of a cell (instead of, as had 

 been supposed, in the substance of a membrane) explains why 

 in the higher animals, the embryo is formed at one point of 

 the yelk surface. Farther, I maintain the accuracy of all the 

 other " marvellous figures," as Bischoff calls them, given by 

 myself of mammiferous ova from the uterus. Before record- 

 ing the results referred to in this communication I had sacri- 

 ficed about 150 rabbits, which yielded 181 ova from the uterus, 

 230 from the Fallopian tube, and an uncounted number from 

 the ovary, — a large proportion of the latter belonging to the 

 dark period pioneered in the inquiry above mentioned. And 



* fSee also my remarks on this subject in Muller's Archiv for 1850, Heft vi. 

 t " Theorie der Befruchtung und iiber die Rolle wclche die Spermatozoideii 

 dabei spielen," in Muller's Archiv, 1847, s. 422. 



X " I3eitrage zur Kenntniss der Geschlechtsverhaltnisse." 



