Packakd.] 



INSECTS OF THE GARDEN. 



17 



contents of another egg ! We have had the pleasure of 

 watching the labors, late in autumn, of this little insect, 

 whose length measures not over three hundredths of an inch, 

 as it was busily engaged upon a bunch of eggs under our 

 object glass, Avith a restless anxiety to rid itself of its burden 

 of infinitesimal eggs by pushing them through the walls of 

 those upon which it stood. Each egg developing perhaps 

 simultaneousl}', we can imagine the race and struggle for ex- 

 istence in that tiny enclosure. The germ of the larger worm 

 rapidl}' collects and arranges the elements of its own form, 

 but it is in vain ; for the smaller being of a more rapid 

 growth is stealthil}' and unawares as constantly pulling 



Fig. 6. 



Ant-lion. 



down that structure of cells and tissues. The race is not 

 always to the strong. 



It often happens that several species of these parasites 

 feed upon a single kind of caterpillar. Thus upon the arm}- 

 worm six species of ichneumons are known to exist, and a 

 Tachina fly is extremely destructive to it. Baron Humboldt 

 tells us in tlie "Views of Nature" that "Bombyx Pini, the 

 Pine Spinner, the most destructive of all the forest insects 

 in P^urope, is infested, according to Ratzeburg, by no less 

 than thirty-five species of parasitical Ichneumonidaj." 



AVe have incidentally alluded to the agency of carnivorous 

 insects in diminishing the numbers of vegetable feeders. 

 The appellation of ant-lions (Fig. 6, ant-lion in its hole; 



17 



