Fruits and Seeds. 201 



V. 



1. The cases in which the diffusion of fruits and 

 seeds is effected by their being sticky are less 

 numerous, and we have no well-marked instance 

 among our native plants. The common Plumbago 

 of South Europe is a well-marked case. There are 

 comparatively few cases in which the same plant 

 uses more than one of these modes of promoting 

 the dispersion of its seeds, still there are some such 

 instances. Thus, in the common Burdock the seeds 

 have a pappus, while the whole flower-head is pro- 

 vided with hooks which readily attach themselves 

 to any passing animal. 



2. But perhaps it will be said that I have picked 

 out special cases ; that others could have been 

 selected which would not bear out, or perhaps 

 would' even negative, the inferences which have 

 been indicated; that I have put "the cart before the 

 horse ; " that the Ash fruit has not a wing in order 

 that it may be carried by the wind, nor the Burdock 

 hooks that the heads may be transported by ani- 

 mals, but that, happening to have wings and hooks, 

 these seeds are thus transported. Now, doubtless 

 there are many points connected with seeds which 

 are as yet unexplained ; in fact, it is partly because 



