NATURAL SELECTION, 
145 
caused by the greater number in Paraguay of a certain fly 
which lays its eggs in the navels of these animals when 
first born," the new-born dying in consequence of these 
inroads. As illustrating the struggle for existence, Prof. 
Haeckel calls attention to the effect of placing goats or 
pigs on one of the isolated oceanic islands uninhabited by 
man. These animals ran wild, and meeting no enemies, and 
finding at first plenty of food, increased in such surprising 
numbers that they killed the other animals and plants. 
Thus, in the course of time, the whole island' was nearly 
depopulated, the goats or pigs even dying out for want 
of food. In some cases dogs were let loose, after the 
island had been overrun by goats or pigs. The dogs, 
finding an abundance of food at first, increased so rapidly 
that their very numbers made food so scarce that they 
finally died out. 
Many other interesting examples of the struggle for 
existence might be mentioned; those just noticed suffice, 
however, to call attention to the important relation exist- 
ing, in this respect, between plants and animals. We 
turn now to a consideration of the facts of Inheritance 
and Variation. 
EN 1:95-17 RANG: 
Not only does the offspring resemble the parent in the 
manner of its growth, in the form of its body and general 
appearance, but, as is well known, mental peculiarities are 
also inherited, the development of particular talents for 
music, painting, etc. being conspicuous in certain families: 
thus, the Bach family have numbered twenty distinguished 
musicians, the family of Weber upwards of forty. Less 
pleasant peculiarities, as those of diseases of all kinds, are 
well known to reappear in posterity both at the same time 
and in the same place as they first appeared in the parent. 
In a word, generally speaking, “Like begets like.” This 
Io 
