Metabolism of Bombyx mori L. VIII. Trace elements

Abstract

Study is made by the spectrographic method of the elemental composition of the silk warm during its different larval phases and in relation to the food ingested with the object of ascertaining the causes of the adaptation of the larva to the mulberry leaf. Leaves of Madura aurantiaca, Broussonetia papyrifera and Ficus carica do not serve as food for the warm and do not seem differ from the natural food (Monis alba) but by the absense or lesser contents in silver of the former. In all the larval phases silver is found predominating in the first three ages, after which elimination of the same is initiated. Mcults and cocoons lack silver. Some considerations are made about the oligoelements in te Bombixmori.