34 PINKS, THYME. [CHAP. 



it is an advantage that the flowers should be proter- 

 ogynous, because the consequence is that the wasp 

 fertilises the upper flowers, and then carries off a fresh 

 supply of pollen from the lower and older ones. 



On the other hand those in which the anthers come 

 to maturity before the pistil are much more numerous. 

 To the category of these plants, which are called 

 proterandrous, belong some species of Thyme, Pinks, 

 Epilobium (Figs. 47, 48), Geranium (Fig. 40), Malva 

 (Figs. 43, 44), (Mallow), Impatiens, Gentians, many 

 of the Labiatae, the Umbellifers, most of the 

 Composites, of the Lobeliaceae, and Campanulaceae. 

 In fact, the greater number of flowers which contain 

 both stamens and pistil, are more or less pro- 

 terandrous. 



Fig. 30 represents a flower of the Pink in the first, 

 or male condition. The stamens are mature, and pro- 

 ject above the disk of the flower, while the pistil is 

 still concealed within the tube. On the other hand 

 Fig. 3 1 represents the same flower in a more advanced 

 condition ; the stamens have shrivelled up, while the 

 pistil now occupies their place. 



Again, Fig. 32 represents a flower of the Thyme 

 (Thymus serpyllum) and shows the four mature sta- 

 mens, aa, and the short, as yet undeveloped pistil, 

 p. Fig. 33, on the contrary, represents a somewhat 

 older flower, in which the stamens are past maturity, 

 while the pistil, p y on the other hand, is considerably 

 elongated, and is ready for the reception of the 

 pollen. 



Here it is at once obvious that insects alighting on 

 the younger (male) flowers would dust themselves with 



