284- Professor Th. Bischoff in Reply to Dr. Martin Barry. 



the microscope, partly, and with greater certainty, by the re- 

 moval of the albumen from the ovum with a sharp needle — a 

 manipulation which it is to be remarked is very difficult. Both 

 methods always showed me that the spermatozoids, though 

 on the ova, were outside the zona. When now it is considered 

 that Dr. Barry in his previous researches never saw the sper- 

 matozoids on the ova; that moreover he obstinately maintains 

 that the albuminous investment around the ovum is not con- 

 sistent throughout, but a membrane inclosing a fluid ; are there 

 not good grounds to doubt the correctness of his observation ? 

 I have been surprised that Mr. Owen has directly assented to 

 it. Mr. Owen shows himself in his own works a much more 

 careful, clear-headed and unprejudiced observer than Dr. 

 Barry. He must know how difficult it is to assure oneself 

 of a difficult point with absolute certainty by a microscopical 

 demonstration ; for one must have the object under his own 

 management, know it very accurately in its other relations, 

 and put it to the test in all sorts of ways before he can come 

 to any certain conclusion. This I request Mr. Owen to do 

 on the next occasion which presents itself, as I myself will 

 continue to keep the point in view. In the mean time it is to 

 be wished that the public may not receive as an established 

 fact the entrance of a spermatozoid into the interior of the 

 ovum. 



I must further mention, that Dr. Barry labours under an 

 erroneous impression in believing that a former statement of 

 his, viz. that my communications in Prof. Wagner's Physi- 

 ology and the illustrative figures in his Icones are defective, 

 has incensed me against him. Those communications were 

 in fact mere fragments, hence I was not at all surprised that 

 Dr. Barry considered them such. They referred besides to 

 the ovum of the dog, which Dr. Barry is not at all acquainted 

 with. I therefore never laid the smallest weight on that state- 

 ment, and had quite forgotten it. My opposition to Barry has 

 arisen purely out of the subject-matter itself, and has been 

 brought forward by me with the greatest reluctance, even on 

 account of that subject-matter. I do not believe that Dr. 

 Barry ever had or will have a more patient and attentive reader 

 than myself. I have spared no pains by repeated perusal and 

 study to extract the sense from his trifling and minute state- 

 ments, from his involved and disjointed descriptions. The 

 difficulties of his style and the indistinctness of his ideas are 

 so great, that probably his labours would have been little 

 known, had not I, acquainted with the subject, communicated 

 them in as intelligible a manner as possible to the German 

 public. Much however has remained quite unintelligible. 



