68 TEXT-BOOK OF FUNGI 



lent of the oogonium, is surmounted by a more or less 

 elongated filament called a trichogyne. The fertilising 

 bodies, which consist of minute non-motile cells, adhere 

 to the trichogyne, and after absorption pass down to the 

 receptive cell. This second type of the sexual process is 

 present and of functional value in the Laboulbeniaceae, 

 and also in the discomycetous fungal element in many 

 Lichens. In an abortive or degenerate form, evidence of 

 this mode of sexual reproduction exists in many genera 

 belonging to the Ascomycetes; vestiges of a trichogyne 

 have also been shown to exist in the Uredineae. Now 

 there is no reason for supposing other than that these two 

 modes of sexual reproduction as presented by the fungi 

 are totally independent in origin, and furthermore, as an 

 exactly similar mode of reproduction with trichogyne and 

 receptive cell is characteristic of the Florideae or red sea- 

 weeds, it is suspected that different groups of fungi have 

 originated independently from the algae, and that the 

 phylogenetic affinity between such groups of fungi and the 

 algae from which they evolved is indicated by homology 

 of the sexual organs in fungus and alga respectively. 



As previously stated, the most important point in con- 

 nection with sexual reproduction consists in the fusion of 

 two nuclei, male and female respectively. A certain 

 amount of cytoplasm passes along with the male nucleus 

 into the female receptive cell, but the significance of this 

 act is considered as of secondary importance as compared 

 with the fusion of sexual nuclei. The discovery of the 

 fusion of numerous male and female nuclei in pairs in the 

 oosphere of Cystopus bliti was considered at the time by 

 some as of primary importance, and the coenocyte went 

 up several degrees in the estimation of those who saw in 



