■210 



BOTAJS/r. 



Pig. 



Swarm- 



spores of C/iondrioder- 

 ma di:forme {Didy- 

 Ttiivm Li^eriianwin of 

 J)e Bary) coalescing or 

 conjugating. X 390. — 

 -After Cienkowski. 



sporangium, which may be distinct (Fig. 144, B), or it may 

 be a flattish, cake-like mass, the so-called mthaliwm, directly 

 derived from the plasmodium. In most cases the spore- 

 bearing masses contain internally, besides the spores, a 

 structure called the Gapillitium, consist- 

 ing of thin-walled, spirally thickened, or 

 otherwise marked tubes- variously disposed 

 (Fig. 144, C, cp). In some cases, where 

 there is a distinct sporangium, the pedi- 

 cel of the latter is continued into it as a 

 central column ; this is known as the Col- 

 umella; it may send out branches which 

 support the walls of the sporangium. 



(a) The latest classification of tlie Myxomycetes 

 is by Rostafinski.* He dlstinguislies seven or- 

 ders, as follows : 



Order I. Protodermeee. Sporangia simple, of regular shape, not 

 possessed of a capillitium, with violet spores: 



Order II. Calcarese. Sporangia simple or compound, often pro- 

 vided with a columella, spores violet or violet brown ; whole fructifica- 

 tion, with more or less de- 

 posits of carbonate of lime. 



This includes many com- 

 mon species, under the 

 genera Pliysarum, Fuligo, 

 Didymium, Spumaria, etc. 



Order III. Amauro- 

 chseteee. Single sporan- 

 gium or aethalium, with- 

 out lime ; spores, capilli- 

 tium, and columella almost 

 always uniformly black, or 

 brownish-violet colored. 



In this order the genus 

 Btemonitis furnishes the 

 most common species. 



Order IV. Anemese. 

 Sporanyiura or aethalium 

 without capillitium or lime ; columella not evident, wall of sporan- 



* "Monografia Sluzowce.'" Dr. Joseph Rostafinski, 1875. An Eng- 

 lish translation of so much as pertains to British species may be found 

 in " The Myxomycetes of Great Britain," by M. C. Cooke, 1877. In a 



Pig. 144. — Fructification of Arcyria incarnatti 

 (A. adnata of Rtfki.). B, young sporangium; C, 

 mature sporangium ruptured ; o », capUlitlum ; 

 p, wall of sporangium. X 20.— After Sachs. 



