94 ROMANCE OF LOW LIFE AMONGST PLANTS. 



in the same genus, in which the androspores are not 

 produced from the same threads as the female cells. 

 In this second group, the vegetative threads are 

 uniformly of two kinds ; there are 

 threads which produce andro- 

 spores, from shortened male cells, 

 and other threads which produce 

 only the inflated female cells, or 

 oogonia. The two kinds are never 

 present on the same thread. The 

 processes of development are the 

 same, and the phenomena are the 

 same, with the exception that the 

 androspores, when they escape 

 from the mother-cells into the 

 surrounding fluid, have to seek out 

 the female threads first, and then 

 afterwards discover the portion of 

 those threads which bears the in- 

 flated cells.^ There is every 

 appearance, in such a process, of 

 a power of selection which we can 

 scarcely believe to exist in simple 

 plants, not accredited even with 

 instinct. But the facts are indis- 

 putable, the selection is made, 

 the escaped androspores find their 

 way to the female threads of 

 their own species, and they attach themselves to those 

 threads, in the immediate vicinity of the inflated cells 



Fig. i6. — Oogonium, sur- 

 rounded by dwarf males 

 attached. 



' AL C. Cooke, "British Fresh Water Algce," p. 149 (18S2); 

 " Introduction to Fresh Water Algce," p. 145 (1890). 



