SLIME FUNGI— MYXOMYCETES 311 



Hence we find that the primary division into two sub- 

 divisions was based upon spore characters. In the first 

 section, the Amaurosporeae, the spores were violet, or brownish 

 violet ; and in the second subdivision, the LamjjrosjJoreae, the 

 spores were variously coloured, but never of any tinge of 

 violet. The next feature which seemed to him most im- 

 portant, or at least most fitting for the purpose of classifica- 

 tion, was the presence or absence of a capillitium. Sub- 

 sidiary to these two features, the presence or absence of lime 

 in the sporangium or capillitium, the production or suppression 

 of a columella, and the perforation of the walls, were employed 

 in the delimitation of families ; after which followed the genera, 

 with their varied predominant characteristics. 



Subsequent writers, having Eostafinski's work as a basis, 

 have proposed alterations and emendations, whilst the 

 majority of mycologists have felt that, although it did much 

 to direct inquiry into a new channel, and classify on sounder 

 principles, the Monograph did not exhaust the subject, but 

 left many occasions for improvement. As we are writing this 

 chapter, the latest attempt at a revised classification has issued 

 from the press.^ In this arrangement the primary subdivision, 

 as to spore coloration, is abolished, and another central idea 

 established, which is thus explained : — " The most pronounced 

 feature in the evolution of the Myxogastres is in connection 

 with spore dissemination, and the following arrangement is 

 based on the relative development of the capillitium, which is 

 seen in its most perfect form in the genera Trichia and 

 Arcyria." 



The entire group is subdivided into four orders, in the 

 following sequence: — (1) Wall of sporangium without lime; 

 capillitium absent, or formed from the wall of the sporangium. 

 (2) Wall of sporangium still without lime ; capillitium 

 originating from a central columella. (3) Wall of sporangium 

 with an external deposit of lime ; capillitium present. (4) 

 Wall of sporangium without external deposit of lime ; capil- 

 litium present, but not springing from a columella. In the 

 introduction the above is the sequence of orders, but in the 



1 A Monograph of the Myxogastres, by G. Massee, Loudon, 1892 : and 

 subsequently that by A. Lister in 1895. 



