87 

 LUDVIG KLEIN ON THE GENUS VOLVOX. 



l',v THOMAS hick:, B.A., B.Sc. 

 Demonstrator and Assistant Lecturer in Botany, Owens ColUg^e, Manchester. 



The interest in Volvox is truly perennial. From the time of 

 Leeuvvenhoek, who first described it nearly 200 years ago (1699), 't 

 has never lacked admirers among microscopists, and has again and 

 again been the subject of investigation by biologists, both from the 

 botanical and the zoological side. To say nothing of many others, 

 the names of Ehrenberg, Williamson, Busk, Cohn, Stein, Butschli, 

 and Wills, are honourably remembered in connection with Volvox, 

 and to them we are indebted for much of the knowledge we now 

 possess of the structure and life-history of this remarkable plant. 



Quite recently, however, Klein has undertaken a reinvestigation 

 of Volvox from the morphological and the biological standpoints, 

 and in a rec^t issue of Pringsheim's Jahrbucher (Zwanzigster Band, 

 Zweites Heft) has published the results of his researches, accom- 

 panied by a searching criticism of the descriptions and statements of 

 previous writers on the subject. The whole paper is well deserving 

 of careful study on the part of botanists and others, and may be 

 strongly commended to their notice for its completeness, for the new 

 and important facts which it brings to light, and for the admirable 

 way in which the contradictory and inconsistent statements current 

 in the literature are either harmonised or corrected. But there are 

 certain portions of it to which the special attention of the botanical 

 readers of ' The Naturalist ' may be directed, and that with an object 

 which will be apparent later on. These are the paragraphs that 

 refer to the habitat of Volvox, the distinctive characters of the 

 species, and the seasonal duration of the sexual and asexual colonies. 

 On all these points our knowledge has hitherto been extremely im- 

 perfect, and not the least merit of Klein's paper is the fulness with 

 which they are dealt with. 



Habitat. — Under this head it will be convenient to include the 

 whole of the influences of the immediate environment as expressed 

 in the vertical range, the physical features of the locality, the 

 associated flora and fauna, and the meteorological conditions. 



Klein found one or both species of Volvox in pools in the plain 

 of the Rhine, and also in what he describes as stagnant old waters of 

 the Rhine. By these latter it may be presumed he means the Rhine 

 waters left behind in the shallows after an overflow. But he never 



March 1890. 



