278 UREDO: PAET ii. 



of these minute fungi have a third and even a fourth 

 order of fruit ; the principle being carried to a maximum 

 in the order Cseomacei. These entophytes have a delicate 

 mycelium, which gives rise to short or obsolete fertile 

 threads, terminated by single spores or chains of spores. 

 These spores when they germinate produce a second 

 order of spores ; these occasionally produce a third order, 

 and so on successively even to a fourth or a fifth order. 

 It is always the last and smallest spores which reproduce 

 the plant. The object of the successive orders seems to 

 be to diminish the size of the spores and to increase 

 their number, that they may more easily enter the 

 stomates of the plants they live upon, and be more easily 

 and widely dispersed by the winds. 



The Uredo Candida, or Cystopus candidus, which takes 

 its name from the white spot it forms on the leaves of 

 the cabbage and other vegetables, is found to produce 

 both female or germ cells and spermatozoids. Long 

 before the white spot is formed on the leaf, the presence of 

 the abundant spawn may be perceived by swellings and 

 deformities in the victim plant. Its filaments, which 

 creep exclusively in the intercellular canals of the cel- 

 lular tissue, are tubular, of unequal diameter, and ex- 

 ceedingly branched, and are always formed of cellulose, 

 either thick- walled and gelatinous, or thin-walled and 

 membranous. From this mycelium, little threads hang 

 down, ending in globular vesicles containing a nearly 

 homogeneous colourless matter, and ultimately an aqueous 

 liquid ; they are supposed to fix the mycelium to the 

 cells of the victim. According to the examination of 

 Mr. Berkeley, M. Tulasne, and others, the branches of 

 the mycelium accumulate in a hollow immediately under 

 the white spot in the skin of the leaf of the plant 

 attacked. From these branches spring bundles of club- 

 shaped tubes, directed perpendicularly towards the upper 

 skin of the leaf, and forming a tuft or little cushion of 



