OKDER MYXOGASTRALES OR SLIME MOLDS 



27 



Fig. 3. Myxogastrales. Ceratiomyxa fruticulosa (Muell.) Macbr. (A) Habit sketch. 

 (B) Development of young fruiting body from Plasmodium. (C) Portion of mature 

 sporophore, showing production of external spores. (After Famintzin and Woronin. 

 From Engler and Prantl: Die natlirlichen Pflanzenfamilien, Leipzig, W. Engelmann.) 



duced. In the Endosporeae, Skupienski (1928) claims that the nuclear 

 fusion does not occur in Didymium difforme until the time for spore forma- 

 tion is at hand. Then the hundreds of nuclei in the Plasmodium unite 

 simultaneously in pairs, this being followed closely by the meiotic divi- 

 sions which give rise to the nuclei of the spores. His interpretation of the 

 nuclear cycle in Didymium thus agrees with Olive's for Ceratiomyxa. 



The Suborder Exosporeae contains but one genus, Ceratiomyxa, with 

 two or three species. Their fructifications appear as simple or branched 

 columns or even as poroid structures 2-6 mm. tall, light in color, growing 

 on decayed logs, stumps, etc. (Fig. 3.) 



The Suborder Endosporeae is recognized by Macbride and Martin 

 (1934) as possessing 59 genera and 380 species. The classification of the 

 numerous genera and species is based upon the type of the peridium 

 and the presence or absence of lime in it and in the elements of the 

 capillitium, the microscopic structure of the latter, the formation of 

 simple or compound fructifications and their size, shape, and color. 

 Further characters are the color, shape, size, and markings of the spores 

 as well as the characters of the Plasmodium, 



