THE SPORE AND ITS DISSEMINATION. 127 
differences between these pseudospores in the several genera are 
confined in some instances to their septation, in others to their 
mode of development. In the Meidiacei the pseudospores are 
more or less globose, produced in chains within an external 
cellular peridium. In the Ceomacei they are simple, sometimes 
produced in chains, and sometimes free, with or without a 
caduceous peduncle. In the Ustelaginei they are simple, dark 
coloured, and occasionally attached in subglobose masses, as 
in Urocystis and Thecaphora, which are more or less compact. 
Fic. 58.— Pseudospores of Fic. 59,—Pseudospores Fic. 60.—Pseudospores of 
Thecaphora hyalina. of Puccinia. Triphragmium, 
In the Pucciniei the distinctive features of the genera are based 
upon the more or less complex nature of the pseudospores, which 
\ 
Fic. 61.—Pseudospores of Phragmidium Fic. 62.—Melampsora salicina. 
bulbosum. (Winter fruit.) 
are bilocular in Puccinia, trilocular in Triphragmium, multilocular 
in Phragmidium, &c. In the curious genus Podisoma the septate 
