. Handbook of medical entomology. Insect pests; Insects as carriers of disease; Medical parasitology. I w \ 50 Poisonous Arthropods that if the nettling hairs are mingled with blood, they immediately produce a change in the red corpuscles. These at once become coarsely crenated, and the roleaux are broken up in the vicinity of the hair (fig. 37b). The corpuscles decrease in size, the coarse crenations are transformed into slender spines which rapidly disap- pear, leaving the corpuscles in the form of spheres, the hght refraction of which con- trasts them sharply with the normal corpuscles. The
. Handbook of medical entomology. Insect pests; Insects as carriers of disease; Medical parasitology. I w \ 50 Poisonous Arthropods that if the nettling hairs are mingled with blood, they immediately produce a change in the red corpuscles. These at once become coarsely crenated, and the roleaux are broken up in the vicinity of the hair (fig. 37b). The corpuscles decrease in size, the coarse crenations are transformed into slender spines which rapidly disap- pear, leaving the corpuscles in the form of spheres, the hght refraction of which con- trasts them sharply with the normal corpuscles. The reaction always begins at the (o) Ordinary hairs and three poison hairs of sub- , 1 -u ^ •*,4- ^J^ a-U^ U^:^ dorsal and lateral tubercles of the larva of the DaSai Snarp pOlUt 01 tnc nair. browntaU moth. Drawing by Miss Kephart. j^ ^^^^ ^^^ ^^ produCcd by purely mechanical means, such as the mingling of minute par- ticles of glass wool, the barbed hairs of a tussock moth, or the other coarser hairs of the brown-tail, with the blood. The question of the source of the poison has been studied in our laboratory by Miss Cornelia \ / / 37,. Kephart. She first confirmed Dr. Tyzzer's general results and then studied carefully fixed specimens of the larvae to determine the distribution of the hairs and their relation to the underlying tissues. The poison hairs (fig. 37), are found on the subdorsal and lateral tubercles (fig. 38), in bunches of from three to twelve on the minute papillae with which the tubercles are thickly covered. The under- lying hypodermis is very greatly thickened, the cells being three or four times the length of the ordinary hypodermal cells and being closely crowded together. Instead of a pore canal (&) Effect of the poison on the blood cor- puscles of man. After Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfe
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectinsectp, bookyear1915
