CONTRIBUTIONS FROM THE CRYPTOGAMIC LABORATORY OF 

 HARVARD UNIVERSITY. — XLVIII. 



A PRELIMINARY ENUMERATION OF THE 

 SOROPHOREiE. 



By Edgar W. Olive. 



Presented by Roland Thaxter. Received November 9, 1901. 



Owing to unavoidable delay iu the publication of a monograph of the 

 Acrasieae and their allies which the writer has in preparation and for 

 which figures have already been drawn, the following preliminary 

 synopsis, which includes all the known forms and which will be sup- 

 plemented as soon as possible by the more extended paper, has seemed 

 advisable. This investigation was undertaken some years since at the 

 suggestion of Professor Thaxter, and a majority of those species that I 

 have myself studied have been kept under observation in pure cultures 

 for a long period, so that the constancy of the characters distinguishing 

 them has been definitely determined. As far as I am aware only one 

 member of the group has been heretofore reported from America, 

 although certain of them are very abundant in laboratory cultures. Of 

 the European representatives several remain unknown except through 

 the original diagnoses, which are unfortunately, in a majority of cases, 

 meagre and unaccompanied by figures. 



A comparison of the conditions presented by the individuals which 

 constitute the so-called fructifications of these organisms indicates that 

 the term spore cannot be properly applied to them in all cases. In the 

 genera Sappinia and Guttulinopsis the individuals, even in mature 

 fructifications, are merely slightly contracted and hardened, secreting no 

 definite wall. At germination such resting individuals, therefore, gradu- 

 ally assume the form of a vegetative amoeba without casting off a spore 

 wall of any kind. In order to distinguish these bodies from true spores, 

 such as occur in a majority of the genera, as well as from the transi- 

 tory resting conditions of isolated vegetating amoeba? which were first 

 characterized as " microcysts " by Cienkowsky, the term pseudospore is 



