TRUE SPIDERS 409 



folded down, like the blade of a pocket-knife, against the main muscular 

 portion of the mandibles. Next, the prey having been fastened down 

 by a few additional threads, the maxilla, or pedipalpi, come into operation, 

 each of which is furnished with a long, leg-like palpus. The food, after 

 having been finely masticated, is then sucked in by the mouth. 



4. Peculiarities. — Garden spiders are restricted in their diet to what 

 happens "to fly into their mouths." Hence each individual must spin 

 its own snare, and there can be no question of a " social state " in the 

 case of these creatures. This unsociability extends even to the sexes, 

 male and female being as a rule bitter enemies. Indeed, the male has 

 usually to exercise great care to escape being devoured by the " stronger 

 sex," the much larger female. The ability, also, of spiders to go without 

 food for a considerable period is intimately connected with the manner 

 in which they obtain their living. (Proofs.) 



D. Respiration. 



Leading a terrestrial life, the spider, like insects, breathes by trachea 

 (see p. 315), to which are added two larger respiratory chambers — the 

 so-called lungs. The entrances to the latter consist of two clefts, 

 distinctly visible on the under surface of the anterior portion of the 

 abdomen. The lungs have the form of sacs ; from a portion of the wall 

 of these, numerous plates, arranged like the leaves of a book (hence also 

 called pulmonary lamellae or pulmonary fans), project into the cavity of 

 the chamber. In these lamellae, which are of very fine structure and 

 constantly fanned by the air, the exchange of the respiratory gases is 

 effected (see Part I., p. 6). Eespiration in spiders being thus partially 

 localized (viz., in the pulmonary lamellae), it follows that the blood 

 must be conducted to these organs, whence the vascular system is more 

 completely developed than in insects (see p. 315). 



E. Reproduction. 



Late in autumn the garden spider lays a number of yellowish eggs, 

 which, as a protection against damp and enemies, it surrounds with a 

 firm web. This little bag of eggs is then suspended in some concealed 

 nook. With the reawakening of insect life in spring, the young spiders, 

 too, escape from the eggs, and from the very first in all respects resemble 

 their parents, thus not undergoing a metamorphosis like insects. 



Other True Spiders. 



Many different kinds of spiders are met with about the house, in the 

 yard, in woods, and in the fields. All of them resemble the garden 

 spider in structure, and are of predaceous habits, pursuing their prey 



