IV.] WINGED SEEDS ON TREES. 79 



believe the general explanations which have been 

 given by botanists will stand any test. 



Let us take for instance fruits formed on the same 

 type as that of the Ash — that is to say, with a long 

 wing, known to botanists as a Samara. Now such a 

 fruit would be of little use to low herbs, which, 

 however, are so numerous. If the wing was accidental, 

 if it were not developed to serve as a means of dis- 

 persion, it would be as likely to occur on low plants 

 and shrubs as on trees. Let us then consider on what 

 kind of plants these fruits are found. They occur on 

 the Ash, Maple, Sycamore, Hornbeam, Pines, Firs 

 and Elm ; while the Lime, as we have seen, has also a 

 leaf attached to the fruits, which answers the same 

 purposes. Seeds of this character therefore occur on 

 a large proportion of our forest trees, and on them 

 alone. But more than this : I have taken one or 

 two of the most accessible works in which seeds 

 are figured, for instance Gaertner's £>e Fructibus et 

 Seminibus, Le Maout and Decaisne (Hooker's transla- 

 tion) Descriptive and Analytical Botany, and Baillon's 

 Histoire des Plantes. I find thirty genera, belonging 

 to twenty-one different natural orders, figured as 

 having seeds or fruits of this form. They are all 

 trees or climbing shrubs, not one being a low herb. 



Let us take another case, that of the plants in which 

 the dispersion of the seeds is eff'ected by means of 

 hooks. Now, if the presence of these hooks were, so 

 to say, accidental, and the dispersion merely a result, 

 we should naturally expect to find some species with 

 hooks in all classes of plants. They would occur, for 

 instance, among trees and on water-plants. On the 

 other hand, if they are developed that they might 



