On the Centrosome of Hepaticese. 1 ' 



Preliminary note. 



BY 



K. Miyake. 



la the summer 1903 in "Beihefte zura Botanischen Central blatt " 

 Ikeno 2) made a remarkable report on the occurrence of Centrosome in the 

 antheridial cells of Marchantia polymorpha. He found Centrosome in every 

 dividing cells of the antheridium. According to his observation just before 

 the cell divides the Centrosome comes out from the nucleus into the Cyto- 

 plasm where it divides into two and each of them is later found at the 

 opposite side of nucleus. When the spindle is formed one can recognize 

 Centrosome in each pole of the spindle. The Centrosome disappears at 

 the end of each division and appears again at the beginning of next divi- 

 sion. Only the Centrosome of the last division, i.e. the division in the 

 formation of the spermatid, persists and functions as a blepharoplast. 

 The Centrosome is always found without any sign of cytoplasmic radiations 

 as usually seen in both animal and plant Centrosomes. The observations 

 of Ikeno are so remarkable aud in many points so different from what 

 has hitherto been described in the cells of Hepatice«3 that I found it 

 desirable to repeat his observations. At first I studied the dividing cells of 

 antheridium in Marchantia po/ymorpha. Then I was able to extend my 

 studies to (Conocephalum conicum, Fegutela conica) Pellia Epiphylla, 

 Malrinoa crispata and a species of Aneura. The material was usually fixed 

 with Flemming's solution and stained either with. Flemming's tripple 

 methods or with Haidenhains's iron-alum hematoxylin. 



Although my study is not yet completed I may be allowed to present 

 some of the results so far obtained. In Marchantia pohjmorpha I studied 

 the nuclear division in antheridium of various stages of development from 

 very young antheridium consisting only of a few cells to the fully developed 



1) Read before Section K of the British Association, Cambridge, Aug. 1904. 



2) Die Spermatogenese von Marchnlia Polymorpha. Beihefte z. Bot. C Bd. XV, 1903. 



