82 METAMOKPHOSES OF MAN 



cuckoo-spits, and lantern-flies, undergo very indistinct 

 metamorphoses, for the simple reason that in spring- 

 ing from the egg, they possess almost all the charac- 

 teristic features of the perfect insect. Hence, they do 

 not exhibit those varied modes of life which we find 

 among other species. The larva of the grasshopper, 

 for example, leaps about, and browses upon the young 

 herbs just as its parents did; the organs of locomotion 

 and digestion having had their adult forms, and rela- 

 tions to each other, from the very commencement of its 

 existence. It is true that its generative apparatus is 

 still to some extent imperfect ; but even at this period 

 the future female carries at the end of her abdomen a 

 sort of doubles word, which is nothing less than the 

 ovipositor by which the eggs will eventually be placed 

 in some sheltered portion of the soil. It wants but 

 wings and an increase of size in order to be a perfect 

 insect in outer appearance. It grows at each period 

 of moulting, and the organs of flight soon appear in 

 the form of stunted projections. At this period the 

 nymph stage begins. Without changing its mode of 

 life, it continues its development, and after the last 

 moult, the wings acquire their full size; the grass- 

 hopper has arrived at the perfect condition, rather by 

 a series of transformations than by metamorphoses. 



Insects with incomplete metamorphoses due to pre- 

 mature development, usually resemble the ideal type 

 when they reach their perfect condition ; those, on the 

 other hand, whose metamorphoses are incomplete, 

 because of an arrest of development, are always more 

 or less departures from the common plan. This brings 

 us to the Mea tribe. 



The eggs of the female flea are scarcely as large as 



