Page:Insects - Their Ways and Means of Living.djvu/134



The facts of reproduction in animais are not well ex- pressed by our name for them. Instead of "reproduc- tion," it would be-truer to say "repeated production," for individuals do not literally reproduce themselves. Genera- tions are serially related, not each to the preceding; they follow one another as do the buds along the twig of a tree,

Flç. 6 3. The external structure of an insect The body of a grasshopper dissected showing the head (H), the thorax and the abdomen (.4b). The head carries the eyes (E), the antennae (,llnt), and the mouth parts, which include the labrum (Lrn), the mandibles (Md), the maxillae {Mx), and the labium (Lb). The thorax consists of three segments {I, 2,), the flrst separate and carrying the first legs (L,), the other two com- bined and carrying the wings (1¢', 11"), and the second and third legs (L,, L.). The abdomen consists of a series of segments; that of the grasshopper bas a large tympanal organ (Tre), probably an ear, on each side of its base. The end of the abdomen carries the external organs of reproduction and egg-laying

and buds on the same twig are identical or nearly so, not because one produces the next, but because all are the result of the same generative forces in the twig. If the spaces of the twig between the buds were shortened until

[ 102 ]

WAYS