358 THE POPULAR SCIENCE MONTHLY. 



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 pro- 

 portion 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, Gartner's "De Fructibus et Seminibus," Le 

 Maout and Decaisne's (Hooker's translation) " Descriptive and Ana- 

 lytical 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 effected by means of hooks. Now, if the presence of 

 these hooks was, so to say, accidental, and the dispersion merely a re- 

 sult, we should naturally exjDect 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 adhere to the skin of quadrupeds, then, having reference to the 

 habits and size of our British mammals, it would be no advantage for 

 a tree or for a water-plant to bear hooked seeds. Now, what are the 

 facts ? There are about thirty English s^^ecies in which the dispersion 

 of the seeds is effected by means of hooks, but not one of these is 

 aquatic, nor is one of them more than four feet high. Nay, I might 

 carry the thing further. We have a number of minute plants, which 

 lie below the level at which seeds would be likelv to be entano-led in 

 fur. Now, none of these, again, have hooked seeds or fruits. It 

 would also seem, as Hildebrand has suggested, that in point of time, 

 also, the appearance of the families of plants in which the fruits or 

 seeds are provided with hooks coincided with that of the land mam- 

 malia. 



Again, let us look at it from another point of view. Let us take 

 our common forest-trees, shrubs, and tall, climbing j^lants not, of 

 course, a natural or botanical group, for they belong to a number of 

 different orders, but a group characterized by attaining to a height of 

 say over eight feet. We will in some cases only count genera ; that is 

 to say, we will count all the willows, for instance, as one. These trees 

 and shrubs are plants with which you are all familiar, and are about 

 thirty-three in number. Now, of these thirty-three no less than eigh- 

 teen have edible fruits or seeds, such as the plum, apple, arbutus, 

 holly, hazel, beech, and rose. Three have seeds Avhich are provided 

 with feathery hairs ; and all the rest, namely, the lime, maple, ash, 

 sycamore, elm, hop, birch, hornbeam, pine, and fir, are provided with 

 a wing. Moreover, as will be seen by the following table, the lower 

 trees and shrubs, such as the cornel, Guelder rose, rose, thorn, privet, 

 elder, yew, and holly, have generally edible berries, much eaten by 

 birds. The winged seeds or fruits characterize the great forest- 

 trees. 



