Archive image from page 32 of The culture of the mulberry. The culture of the mulberry silkworm cultureofmulberr39kell Year: 1903 ( DISEASES OF SILKWORMS. 2g of tin- disease; the internal signs are oval corpuscles only risible through the microscope. Worms healthy born may contract pebrine during life, but this may not prevent their spinning, as the disease does not reach it- climax before the chrysalid or moth stage, and in its incipiency the worm is strong enough to spin, though the moth will produce diseased Hence the necessity of repeating the microscopical examination for each generation
Archive image from page 32 of The culture of the mulberry. The culture of the mulberry silkworm cultureofmulberr39kell Year: 1903 ( DISEASES OF SILKWORMS. 2g of tin- disease; the internal signs are oval corpuscles only risible through the microscope. Worms healthy born may contract pebrine during life, but this may not prevent their spinning, as the disease does not reach it- climax before the chrysalid or moth stage, and in its incipiency the worm is strong enough to spin, though the moth will produce diseased Hence the necessity of repeating the microscopical examination for each generation of worms. Pebrine is not always visible, and when latent induces other diseases. When only one crop of cocoons is made annually, it is comparatively easy to resist pebrine. as the germ of it. out- side of an egg, retains its vitality not longer than seven months. The disease takes thirty days to develop: therefore, if worms from pebrinized egg> can be made to spin within twenty- five days after hatching, they may yield a fair harvest of cocoons. In any case, however, it is only safe to use pure eggs, as pebrine, even in undeveloped stages, renders the worm more liable to contract all other dis- eases. FLACHERIE, OR FLACCIDITY. This is now the most dreaded disease among European silk- worms. In general, worms are struck with it after their fourth molt, when they are mature, or even while spinning (tig. 12). Without any apparent cause, they begin to Languish, then remain completely still, and shortly die. They blac-kon after death (fig. 13), and give out a disagreeable odor. Often entire chamber- perish in a day. Again, the progress of the disease may be alow, the worms even spinning their cocoons, but. dying m the chrysalid state, they putrify and soil the cocoon, thus greatly diminishing the value oi the harvest Flachene is but another name for indigestion. Pasteur and many other scientist- assert that Hacherie is due to ferments and vibrioni developing in the intestinal ca
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