Auxospore-formation of CItactoceras debile 



Cleve. 



By 

 Kichisaburo Yendo and Jiro Ikari. 



With Plate. 



V 



The auxospore-formation of the Diatoms has been observed 

 in about 20 genera. This, however, can by no means be said 

 as extensive when compared with the whole number of the 

 genera — about 160.' From this fact, a classification of the 

 modes of auxospore-formation as has been tried by Meresch- 

 kowsky may hardly be said to be conclusive. 



The auxospore-formation of Chaetoceras has been first 

 observed by Sciiutt' in Ch. curvisetum Cleve and Ch. 

 contortum SCHUTT from the Baltic. Gran reports that he 

 has .-ilso observed it in several species, — Ch. constrictum, Ch. 

 diadema, Ch. debile, and Ch. teres. He simply states that 

 it is in the same way in these species as in Ch. curvisetum. 



In April this year, we had a very favourable opportunity of 

 observing the auxospore-formation of Chactoceras debile CLEVE 

 at the Marine Laboratory of Oshoro near Otaru Bay. The 



1) After .-'chitt in Engl. u. Pbantl : Pflanzenfamilien. I. The!!, lb. 



2) - ! taxoiporenbildang der Gattnng Cha Ber. d. d. IS. 

 <r. Bd. VJ] 1889, p. 861 . In this pap t B ni'ir gave ao material. 

 J'.nt aflerwards (Pflanzenfamilien, l.c.) he identified them with Ch Seal pi and 

 OK, mt ii. 'lii nonymized bj Ghas to < Clevi and 



o tfortum & in 1 1 re pectively. 



8: Den Nonke Nordhave-Ezpediti n 1878 1878, Botanik. Protophyta, 

 I 



