112 BOTANICAL MAGAZINE. [Vol. XIX, 



Notwithstanding the contrary statement of Miyake I have no doubt 

 about the real existence of the centrosomes in question and so it seemed 

 to me to be quite unnecessary to look for them once more. Never- 

 theless in order to make my assertion mucli firmer, I made, soon after 

 his paper came into my hands, a special re-examination of my slides and 

 could refind easily almost all stages of centrosomes figured in " Taf." Ill 

 of my last paper. They are always very small, but distinct round bodies, 

 which are stained pretty intensely and are surrounded by a clear space 

 ("Hof" of German authors). I have shown also some of my sections to 

 Dr. K. Toyama, lecturer in the Zoological Laboratory, who is concerned 

 in cytological investigations of animals ; he carefully examined my slides 

 and asserted me positively that he can distinctly see bodies, which I call 

 centrosomes. 



Even in the last division of the antheridium Miyake could discover 

 centrosomes in none of the Hepaticae examined by him. I re-examined 

 also my slides in such stage of division and from this re-examination I 

 cannot but repeat here what was said in my last paper, namely, " in der 



That habe ich Praparate erhalten, in denen sich zahlreiche Schnitte, 



je mit vielen hundert Teilungsfiguren im Aster befinden ; bei diesen kann 

 man an jedem Spiudelpol ohne Ausnahme je ein Centrosom wahr- 

 nehmen " 1> . 



According to Miyake, his treatment of materials was quite similar 

 to mine (fixation with Flemming's solution and staining with Heiden- 

 hain's iron-hfematoxyline or safranin-gentian-violet-orange) and so it is 

 rather surprising that the study of similar materials similarly treated 

 might lead to so different results. But as it is well known to the 

 students of cytology, we encounter the greatest difficulty in the treatment 

 of such minute objects and in such cases as we are now concerned, the 

 slightest difference of manipulation may give rise to totally different results. 

 Moreover even in those cases, when centrosomes are clearly discernible, it is 

 not at all improbable, that man might easily overlook them, unless he 

 shall work with the utmost care and under the most favourable condition 

 of illumiuation. Even for my part, I was at first led to the erroneous 

 assumption that in the young antheridium of Marchantia centrosomes are 

 lacking, but after the most careful observation under the best condition 

 of illumination once revealed me the presence of centrosomes in one cell, 

 I searched for thein in others and then rarely failed to discover them. 



1) Ikeno 1. c, p. 74. 



