DEGENERACY OF FLOWERS. 267 



What, then, have been the causes which have given rise 

 to the features generally characteristic of anemophilous 

 flowers ? In the first place, it must be remembered that 

 such are far from absolute. Smooth and easily scattered 

 pollen,* Miiller remarks, is the only positive character 

 common to these plants. Mr. C. F. White, F.L.S., however, 

 tells me that from his researches he very much distrusts the 

 division so generally accepted between wind- and insect- 

 borne pollens. It is his opinion that there is no pollen-grain 

 so smooth but that the hairs on the limbs of a bee or fly can 

 hold it. Moreover, no pollen, however massed together, can 

 possibly be heavier than, say, a thistle seed and its down 

 attached, which the wind can carry with perfect facility ; so 

 that to draw any distinction on that score seems to me to 

 be very far-fetched.f With respect to the pollen of Grasses, 

 Mr. White observes that it is perhaps forgotten that, although 

 smooth in water, when dry they are notably wrinkled into 

 sharply angled and irregular shapes. 



Mr. Edge worth J has figured many forms of pollen of 

 anemophilous genera, several of which show no signs of 

 smoothness or rotundity, such as Alopecurus prate7isis, Car ex 

 arenaria, and G. panica, which, like Juncus effusus, is oblong, 

 with sharp edges, all of which are at right angles or nearly 

 so. Again, TypJia latifoUa and Cupressus have octahedral 

 pollen ; Areca Baueri, Geratozamia, Bheum, Mercurialis, Oak, 

 etc., have more or less sharply pointed spindle-shaped grains. 



* See Mr. A. W. Bennett's paper, On the Form of Pollen-grains in 

 Reference to the Fertilisation of Flowers, Brit. Assoc. Rep., 1874. 



t I would here allude to another d prio7-i assumption. It has been 

 thought that the two pouches on the pollen of the Fir aid it in trans- 

 portation; but unless they were filled with some gas lighter than air 

 they only increase the weight of the grain. 



X Pollen, by Mr. M. Pakenham Edgeworth, F.L.S., 1877. 



