38 MICROSCOPIC FUNGI. 



which are derived from the spermogones, and 

 which have not yet been known to germinate ; 

 Stylospores, produced either singly, or in bead-like, 

 or moniliform, strings, and which either precede or 

 are associated with the true spores ; Spores, some- 

 times simple, but often complex; and Sporidia, or 

 secondary sporules, which are produced on the 

 germinating threads of the true spores. 



The various genera of these endophytes owe 

 their distinctions to the form, or mode of develop- 

 ment of their true spores. In one instance these 

 spores are united in pairs, or divided by a septum, 

 so that they are two -celled : these are named Puc- 

 cinia. In another instance the spores are one- 

 celled, and at first borne upon a stalk or peduncle, 

 from which they are detached in ripening : such 

 are called Trichobasis. It is unnecessary here to 

 indicate all the variations to illustrate the fact that 

 the generic distinctions are based upon the cha- 

 racters of the true spores. How unsatisfactory 

 such a mode will appear, when subjected to expe- 

 rience day by day, a botanist would suspect. In 

 the same pustule, resting upon the same cushion of 

 mycelium, the spores of an Aregma will be found 

 with those of a Lecythea, and those of a Puccinia 

 with Trichobasis. More than this has even been 

 affirmed. The alternation of generations, known 

 to students in the animal world, is here repeated in 

 the vegetable. Dr. de Barv declares that certain 

 data appear to indicate that JEcidium constitutes 



