EEPEODUCTION 



435 



the case. After their liberation they are attracted to the 

 archegonia by some constituent of the mucilaginous matter 

 which is excreted from their necks when they open (fig. 

 184). In the Mosses this has been ascertained to be cane- 



FIG. 183. DEVELOPMENT OF THE ANTHERIDIUM IN THE FERN. (After Kny.) 



sugar, in the Ferns it is malic acid or one of its salts. In 

 the Khodophycese and such Ascomycetes as exhibit sexual- 

 reproduction, the passive male gamete, often called a 

 spermatium, instead of an antherozoid, is floated to the 

 female organ or its trichogyne by currents in the water. 



FIG. 184. DEVELOPMENT OF THE ARCHEGONIUM OF THE FERN. (After Kny.) 



In the Phanerogams, where the female gametophyte is 

 always attached to the parent sporophyte, such a means 

 of fertilisation is of course impossible. For fertilisation to 

 take place it is necessary that the two gametophytes shall 

 be produced in close propinquity to each other. This is 



F F 2 



