The Ohio ^JS^aturalist, 



PUBLISHED BY 



The Biological Club of the Ohio Stale Uni'versity. 

 Volume IX. NOVEMBER, 1908. No. 1. 



TABLE OF CONTENTS. 



SCHAFFNEK— The Centrosomes of Marehantia polymorplia 383 



DelaToree Bueno— The Broken Henielytra in certain Halobatiuae 389 



SCHAFF.vER— The Air Cavities of Equisetum as Water Reservoirs 393 



News and Note.s 394 



Hammond— Meeting of the Biologieal Club 395 



THE CENTROSOMES OF MARCHANTIA POLYMORPHA.* 



John H. Schaffxer. 



Since Ikeno reported the presence of centrosomes in the 

 antheridial cells of Marehantia polymorplia, in 1903 and 1904, 

 his results have been disputed by several investigators. Ikeno 

 found centrosomes at the poles of the spindle in all the genera- 

 tions of antheridial cells and also observed that these bodies are 

 at the poles of the last division spindle, where they begin to be 

 transformed into the bodies, the so-called blepharoplasts, from 

 which the fiagella of the spermatozoid are developed. He came 

 to the -same conclusion, therefore, as Belajeff had several years 

 before, through his studies on Gymnogramme and Marsilea, that 

 the blepharoplast is a centrosome. 



Miyake, in 1905, failed to see centrosome-like bodies at the 

 poles of the division spindle of the antheridial cells of Marehantia 

 except in the last division, i. e., in the spermatozoid mother cells. 

 From this negative evidence he concludes that Marehantia has 

 no centrosomes. He says: "But my present study seems to 

 show that there is no true centrosome at least in the Hepaticeae, 

 agreeing with the conclusion of the recent study of Gregoire and 

 Bergh. The centrosome hitherto reported in the cells of the 

 Hepaticeae are nothing but a center of cytoplasmic radiation." 

 It is difficult to imagine how one is to distinguish betAveen "true 

 centrosomes" and "centres of cytoplasmic radiation," especially 

 when the bodies in question are situated at the poles of the 

 spindle. 



Ikeno, in reply to Miyake, firmly maintains his former 

 position as follows: "Notwithstanding the contrary statement 

 of Miyake, I have no doubt about the real existence of the 



'- ^f.i M 



^Contributions from'Tthe Botanical Laboratory of Ohio State Uni- 

 versity, XXXVII. ' 



