A. E. Verrlll — The Bermuda Islands. 591 



will eagerly devour the eggs and young of birds, insects, reptiles, 

 and any other animal food that they can find, when food is scarce, 

 and they are half-starved. The early writers told of the boldness 

 and voracity of the rats in killing chickens, and even entering their 

 houses and eating their clothes, showing that they Mere unable to 

 find more natural food and were nearly starved, for they do not 

 ordinarily enter houses. 



At such times they probably girdled and killed many trees with 

 edible bark, as other rodents are apt to do. 



o. — Effects of Injurious Insects; Snails and Slugs. 



That large numbers of injurious insects were introduced by the 

 settlers, from time to time, is certain. Some of these, like the scale- 

 insects, are capable of killing trees and even of exterminating species 

 of plants over a limited area like the Bermudas. 



The rapid destruction of the orange and lemon trees by scale- 

 insects, in modern times, is a good example of their destructive 

 powers. But we know too little of the Bermudian insects and the 

 effects that the}^ may have produced on various plants, to warrant 

 any lengthy discussion of the subject in this place. 



In the chapter on insects, the most important injurious species will 

 be discussed, with their habits. So far as known the scale-insects 

 have been the most destructive here, especially to the citrus fruit 

 trees, figs, etc. (See eh. 3V, j.) 



Most of the larger slugs and snails have been introduced by man. 

 The most injurious of all these is the "spiral snail" of the Bermu- 

 dians (Mumina decollata), which was first introduced accidental l} r in 

 187 7, at Mt. Langton, Hamilton, but it has increased prodigiously 

 and has now spread all over the Main Island, doing a very great 

 amount of damage to the crops. They have here few natural enemies 

 to check their rapid increase, though the Tropic-bird has learned to 

 eat them. (See ch. 36.) 



Whether such snails and slugs are capable of exterminating any 

 wild and common species of plants may be doubted by many, but they 

 are certainly capable of interfering with their growth and changing 

 the ratios of various species of plants to each other, and they might 

 easily destroy rare species, or even some of the more common ones, 

 in case the foliage should be particularly attractive to them for food. 



Domestic animals of various kinds are also important factors in 

 altering the natural vegetation by destroying certain species tliat 

 they prefer. Goats and sheep are particularly destructive, in this 



