76 CYTOPLASMIC STRUCTURES IN THE SEMINAL EPITHELIUM OF THE OPOSSUM. 



trate certain nerve cells (since then another example of this penetration has been 

 reported by Ross, 1915), an opinion which is strongly supported by the publica- 

 tions of Nusbaum's pupils. 



At the time I was making my report at Innsbruck, Holmgren (1914) published 

 a paper in which he reaffirmed the continuity of the "Trophozyten" and their 

 processes with the intracellular apparatus of the ganglion cell, his conclusions being 

 based especially upon the study of preparations made after Kopsch's method. In 

 another paper (1915) he insists again upon the correctness of his views and expresses 

 at the same time his dissatisfaction with the opinion given in my review, an opinion 

 which I have just summarized. Regarding Holmgren's paper I wish to say this: 

 When I undertook my review I was entirely unprejudiced. My conclusions were 

 based, first, upon a thorough study of the literature (in fact Holmgren can not 

 reproach me with any gaps or misrepresentation of his views quite an achievement 

 considering his prolixity and versatility) ; second, upon a study of preparations of 

 my own; third, upon a number of Holmgren's preparations. Details concerning 

 the latter can not be given, as the preparations themselves have been returned to 

 Holmgren and the notes I took at Liege are not available. I recall very clearly, 

 however, that, notwithstanding the persuasive notes which Holmgren sent with the 

 preparations, I failed to be convinced. My skeptical attitude towards Holmgren's 

 theory, therefore, is well based, and he himself is in part responsible for it. I can 

 not help wondering why, if he really had the facts, he did not come to Innsbruck 

 and show his preparations instead of writing articles, for I had already informed 

 him of my conclusions. 



Since my review and Holmgren's first article (1914), a paper by Ramon y 

 Cajal (1914) has appeared, in which the author discusses the same question. His 

 opinion on most of the points is entirely in accord with my own. He calls the 

 intracellular apparatus aparato tubular de Golgi-Holmgren, meaning two things: 

 First, that the two formations are identical, a view in agreement with my own, 

 exception being made, however, for the non-nervous cells with diffuse trophos- 

 pongium, for which it can not hold; second, that these formations are a system of 

 ducts, an opinion I must regard with some skepticism. Speaking of the possible 

 connections of the apparatus with processes of trophocytes, Ramon y Cajal expresses 

 himself as follows (p. 211): 



"Lo que importa notar particularmente es que, si positivamente en ciertos elementos 

 ganglionares de los vertebrados, existen condustos radiados para alojar apendices de los 

 trofocitos, estos apendices no se hallan en continuacion substancial con el aparato de 

 Golgi. Ni acabamos de persuadirnos de que las cistadas celulas nutritivas representen 

 disposition general. A nuestro juicio, no es posible descubrir el menor resto de ellas en 

 los epithelios, ni en la ininensa mayoria de las neuronas centrales, ni en los elementos 

 del embrion di uno a dos dias, donde el aparato de Golgi esta bien diferenciado." 



Another point of great interest is the question of relationship between the 

 apparatus and the chondriosomes. In 1914 I thought it safe enough to conclude 

 that in nerve cells (p. 18), as well as in other cells (pp. 35-36), the apparatus is a 

 structure different from the chondriosomes, although the possibility of genetic 



