2^4 THE ENTOMOLOGIST. 



to be far more easily distributed by winds than the seeds of 

 flowering plants, and they are thus always ready to occupy 

 any vacant places in suitable localities, and to compete with 

 the less vigorous flowering plants. But where insects are so 

 scarce, all plants which require insect fertilisation, whether 

 constantly to enable them to produce seed at all or 

 occasionally to keep up their constitutional vigour by crossing, 

 must be at a great disadvantage; and thus the scanty flora 

 which oceanic islands must always possess, peopled as they 

 usually are by waifs and strays from other lands, is rendered 

 still more scanty by the weeding out of all such as depend 

 largely on insect fertilisation for their full development. It 

 seems probable, therefore, that the preponderance of ferns in 

 islands (considered in mass of individuals, rather than in 

 number of species) is largely due to the absence of competing 

 phaenogamous plants ; and that this is in great part due to 

 the scarcity of insects. In other oceanic islands — such as 

 New Zealand and the Galapagos, where ferns, although 

 tolerably abundant, form no such predominant feature in the 

 vegetation, but where the scarcity of flower-haunting insects 

 is almost equally marked — we find a great preponderance of 

 small, green, or otherwise inconspicuous flowers, indicating 

 that only such plants have been enabled to flourish there as 

 are independent of insect fertilisation. In the Galapagos — 

 which are, perhaps, even more deficient in flying insects than 

 Juan Fernandez — this is so striking a feature that Mr. Darwin 

 speaks of the vegetation as consisting in great part of 

 " wretched-looking weeds," and states that " it was some 

 time before he discovered that almost every plant was in 

 flower at the time of his visit." He also says that he " did 

 not see one beautiful flower" in the islands. It appears, 

 however, that CompositaB, Leguminosae, Rubiaceae, and 

 Solanaceae, form a large proportion of the flowering plants; 

 and, as these are orders which usually require insect 

 fertilisation, we must suppose either that they have become 

 modified so as to be self-fertilised, or that they are fertilised 

 by the visits of the minule Diptera and Hymenoptera, which 

 are the only insects recorded from these islands. 



In Juan Fernandez, on the other hand, there is no such 

 total deficiency of showy flowers. 1 am informed by Rlr. 

 Moseley that a variety of the maguoliaceous winter's baik 



