Acquired Immunity in Silkworms

[摘要] Silkworms are extremely susceptible to certain types of bacteria which often contaminate the mulberry leaves. The origin of this contamination is still imperfectly understood, notwithstanding the fact that much work has been done in this laboratory to trace the source. Therefore, some matters, to be described, that deal with the maintenance of a healthy stock are purely empirical. Experience in rearing large numbers of silkworms for three seasons (1922, 1923 and 1924) has clearly shown that clean food is one very important factor. Worms can be maintained in a healthy state if the mulberry leaves are clean, namely, free from bird feces, mulberry fruit juice spots and other visible dirt. When a bacterial disease once appears in a culture it is extremely difficult to eradicate; for, as has been pointed out in a previous publication (1) dealing with such a disease, the living sick worms contaminate everything through defecations, and when they die soil the food with their fluids.

[学科分类] 生物科学（综合）