POLLINA TION—FERTILlZATIOn. 



129 



autumnal flowers of the 

 and Trifolium subter- 

 raneum. In the spring 

 these plants produce 

 normal flowers ; but in 

 the autumn the flowers 

 scarcely look like 

 flowers at all. There 

 is no stigmatic surface ; 

 the ovules and anthera 

 are in the same cavity 

 or ovary ; this cavity 

 does not open ; the 

 pollen - tubes ^w h i t e 

 cords in the illustra- 

 tion) bore holes through 

 the anther-lobes at the 

 top of the cavity and 

 penetrate the ovules 

 below, which ripen 

 perfect seeds. Masters 



Dead Nettle (Pig. 183), the Violet, Oxalis, 



Fig. 185. — Milkwort {Polygala vulgaris). 



Fig. 184. — Bryonia dioicay cf and ? pl.ante. 



tells US, in his "Vegetable Phj'si- 

 ology," of plants in which pollen- 

 grains are produced in the ovule it- 

 self One step further, and we see 

 294. Parthenogenesis, or Virgin 

 parentage, already defined (40). 

 Spallanzani (\,he latter part of the 

 last century) found that the S flowers 

 of the Hemp (which is dioecious) pro- 

 duce perfect seeds without the aid of 

 pollen ; Naudin and Decaisne grew 

 a second generation of Hemp from 

 virgin seeds. Naudin discovered the 

 same thing in the Common Bryony 

 (Pig. 184), which is also dicBcious.* 

 The most remarkable plant with this 

 habit is the Ccelebogyne, or Virgin- 

 flower (L. ccelebs, unmarried ; Gr. 

 gyne, woman). It was discovered 

 in New Holland, and introduced iiito 

 the English Botanical Gardens in 

 1829. It is dioecious, and placed in 

 the Euphorbia Pamily ; its fruit re- 

 sembles that of the Three -seeded 

 Mercury. No male plant was brought 

 to Europe ; the flowers show no sign 

 of pollinic action by cross-fertiliza- 



* The Weeping Willow produces new generations in this way con- 

 tinually and perfectly, Herbert Spencer tells us. He calls the process 

 Agamogenesis, — Gr. agamos, without marriage. 



