30 British Fungi. 



and tlie outcome of sexual fertilization_, tlien tlie asci 

 will notbe liomologous_,but only analogous with basidia. 

 In addition to the modes of reproduction already 

 described^ which are the most highly evolved in the 

 various sections of which they are respectively 

 characteristic^ it is important to bear in mind that 

 other modes of reproduction exists in fact thousands 

 of fungi have two, and in many cases more than two, 

 distinct forms of reproductive organs, usually very 

 dissimilar in both structure and origin. All such as 

 do not come under the types of reproductive organs 

 already described, are known collectively as gonidial 

 modes of reproduction, and agree in'being asexual in 

 origin. Such gonidial reproductive organs are most 

 frequent in the Phy corny cetes and Ascomycetes, but are 

 by no means rare in the B asidiomy cetes , and in the 

 first named group are as a rule far more character- 

 istic of the species, from the systematist's point of 

 view, than the sexual reproductive organs. For 

 example, in many species of 2Iuccr, popularly called 

 moulds, and PeroJiospora, the white cobweb-like 

 mildews on the leaves of living plants, the gonidial 

 stasre is the only one known. In such cases the 

 accepted proof that the gonidial condition of a species, 

 where the sexual stage is unknown, belongs to the 

 same genus as another species having both gonidial 

 and sexual modes of reproduction, depends on close 

 morphological and biological agreements between the 

 two gonidial forms. In other species the gonidial 

 phase is absent. Gonidial or secondary reproductive 

 organs present far more variety of structure than the 

 j)rimary ones already described, and will be explained 



