CABPOPHYTA. 



177 



a short branch; one of these becomes the carpogone (c, 

 Fig. 98), and the other the antherid {h, Fig. 98). 



320. Fertilization is efEected by the direct union of 

 protoplasm. Eight or ten branches then grow out just 

 below the carpogone, and growing upward soon completely 

 cover it with a cellular coat which eventually becomes 

 hardened and turns brownish in color, constituting the 

 pericarp of the spore-fruit (Fig. 99). In some cases it ap- 

 pears that there is no actual fertilization, and that the 

 spore-fruit develops without it, the sexual organ being so 

 much degenerated as to be functionless. 



321. The carpogone inside of the pericarp gives rise, by 

 branching, to one or more large cells filled at first with 

 granular protoplasm, which soon forms two to eight spores 

 (Fig. 100). Upon its outer surface 

 the spore-fruit develops long filaments 

 (known as appendages), probably for 

 holdfasts. In some genera these ter- 

 minate in hooks (Fig. 99); others are 

 dichotomously branched; still others 

 are needle-shaped; while many end 

 irregularly. The spore-fruits remain 

 during the winter upon the fallen and 



. . , T /. n 1 Fig. 100.— a ruptured 



decaying leaves, and finally, by rup- spore-fruit of Goose- 



. .11 'berry-niildew, showing 



turinff, permit the sacs, with the con- the escaping sac,with its 



^ '■ contained spores. Mag- 



tained spores, to escape. m^&& ahout 270 times. 



322. The Herbarium-mould (Burotium) is a near rela- 

 tive of the Powdery Mildews. It is common on poorly 

 dried specimens in the herbarium, and also on decaying 

 fruits, wood, etc. It sends up vertical branches, which 

 swell at the top and bear a great number of small protu- 



