Functions of the Central Nervous System in Relation to Quantitative Characters in a W-Translocated strain of Silkworm, <i>Bombyx mori</i> L.

Abstract

(1) Although the silk-layer weight of females is usually heavier than that of males in the common silkworm strain, this relation is reversed in the W-translocated strain.(2) The functional relationships among the three organs, brain, suboesophageal ganglion and corpora allata which are related to quantitative characters such as the weight of the silk-layer and voltinism were examined in a series of experiments in organ transplantation.(3) By transplantation of the brain-suboesophageal ganglion complex of females of the W-translocated silkworm strain to “non-diapause larvae” the silk-layer weight of the recipient is more decreased and voltinism is more strongly changed in non- diapause direction than in the case of transplantation of suboesophageal ganglion alone.(4) By transplantation of the brain-suboespohageal ganglion complex of males of the W-translocated silkworm strain to “non-diapause larvae” the silk-layer weight of the recipients is more increased and the voltinism is more strongly changed in diapause direction than in the case of transplantation of the suboesophageal ganglion alone.(5) By transplantation of the brain-corpora allata complex of females of the W-translocated silkwrom strain to “diapause larvae” the silk-layer weight of the recipients is more decreased and the frequency of non-diapause eggs within one batch becomes higher than by transplantation of corpora allata alone.(6) By transplantation of the brain-corpora allata complex of males of the W- translocated silkworm strain to “diapause larvae” the silk-layer weight of the recipient is more increased and the percentage of non-diapause eggs in one batch (laid by one moth) is more decreased than in the case of transplantation of corpora allata alone.(7) It is assumed from the above-mentioned findings that the brain of females of the W-translocated strains weakly inhibits the functional activity of suboesophageal ganglion and weakly acclerates that of corpora allata through nerve commissures. It seems, on the contrary, that the brain of males of the same strain weakly accelerates the functional activity of suboesophageal ganglion and weakly inhibits that of corpora allata through the nerve commissures.