Publisher's Synopsis
This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1910 edition. Excerpt: ... 39.--Sections of alkaline gland of sting. tion of either gland alone do not die for a long time even in spite of the necessary mutilation, while (3) successive inoculations of the same fly first from one gland and then from the other produce death in a much shorter time than when inoculated from one gland alone--presumably as soon as the two liquids mix within the body. The two secretions, one acid and the other alkaline, are poured together into the base of the sting bulb and mix within the cavity of the latter. The resulting poison is then driven through the channel in the shaft to near the tip of the latter, where it makes its exit into the wound. Since the large poison sac is not muscular, the poison is not forced through the sting by it, as is often supposed. A glance at figure 57 (see p. 135) will show that the accessory plates of the siting support several very compact sets of muscles on their inner face-. These muscles so act during the process of stinging that the triangular plates (figs. 36 and 37, Tit) turn upon their hinge-joint articulations with the oblong plates (Ob). By this motion of the triangular plates the attached lancets (Let) are moved back and forth alonrr the tracks on the lower edges of the sheath and its arms (67.l). Kach of these tracks consists of a ridge with a constricted base which dovetails into a correspondingly shaped groove on the dorsal surface of the lancet. This structure, as seen in cross sections through tin' shaft and bulb of the sting, is shown by fig. 40 A, 15, and C. The lancets are thus held firmly in place, while at the same time they may slide back and forth with perfect freedom. The figures show also that all three parts of the sting are hollow, each containing a prolongation (be) of the...
