Page:Insects - Their Ways and Means of Living.djvu/369

 CATERPII.I.AR AND THE MOTH

The stomach is contracted to a mere remnant of its former size (A, l'ent), and its walls are thrown into thick corrugations. The intestine (SI,t) is about the same as in the earlier stage of the moth (B). Since the moth of the tent caterpillar probably eats nothing, it has little use for a stomach. The intestine, however, must serve as an outlet for the lalpighian tubules (Mal), since the latter remain functional through the pupal stage. The secretion of the tubules contains great numbers of minute spherical crystals, which accunqu- late in the rectal sac (Rect) where they form the orange- colored mass contained in this organ and discharged as soon as the moth leaves the cocoon. Most of the male moths of the tent caterpillar emerge from the cocoons several davs in advance of the females. At this time their bodies contain an abundance of fat which fills the cells of the fat tissue as droplets of oil. This fat is probably an energy-forming reserve which the male moth inherits from the caterpillar, for the internal reproductive organs are hOt vet fully developed and do hOt become functional until "about the time the females are out of their cocoons. The bodies of the female tent caterpillar moths, on the other hand, contain little or no fat tissue; but each female is fully matured when she emerges from the cocoon, and her ovaries are full of ripe eggs ready to be laid as mon as the fertilizing element is received from the male (Fig. I65, Or). The spermatozoa will be stored in a special recep- tacle, the spermatheca (Spm), which is connected with the exit duct of the ovaries (I'Ç¢) by a short tube. Each egg is then fertilized as it issues from the oviduct. The ma- terial that will form the covering of the eggs when laid is a clear, brown liquid contained in two great sacs (Fig. 65, Res) that open into the end of the median oviduct (lg). Each sac is the reservoir of a long tubular gland (C/G/). The liquid must be somehow mixed with air when it is discharged over the eggs to give the egg covering

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