FERTILIZATION. 69 



which is never motile, to reach the oosphere, has except in 

 rare instances been discarded, and in its stead, in addition 

 to self-fertilization, where the pollen fertilizes the oospheres 

 of the same flower, wind and members of the animal 

 kingdom, more especially certain groups of insects, perform 

 this function. Flowers that are fertilized by the agency of 

 wind, as Conifers, hazel, etc., are said to be aneviophilous, 

 whereas those flowers that utilize insects for this purpose are 

 said to be entotnophilous. The last method is most general, 

 as proved by the variety of colour, form, and scent developed 

 by the majority of flowering plants, and has perhaps at the 

 present day attained its maximum of development, as 

 evidence is at hand to show that even this method, which 

 has done so much towards enabling plant life to reach its 

 present high state of differentiation, is in some quarters 

 being superseded by a reversion to the older method of 

 self-fertilization, illustrated by many of the members of the 

 Violet izm-A^ (Violacece) and others, where certain flowers 

 are produced having the calyx or outer green covering 

 permanently closed, thus effectually preventing cross-fertiliz- 

 ation; the corolla or attractive coloured portion with its 

 scent and honey-secreting structures being suppressed ; the 

 stamens are also fewer in number than in the older type of 

 violet flower. The term deistogatnous is applied to such 

 permanently closed flowers, obviously constructed for the 

 purpose of securing self-fertilization. The proof that the 

 last-mentioned mode of reproduction has superseded the 

 entomophilous method, is shown by the fact that in most of 

 our wild violets cleistogamous and entomophilous flowers 

 are both still produced, the latter, in the irregular or 

 zygomorphic corolla, furnished with a nectary and scent 

 glands, pointing to a high state of differentiation in 



