occurrence of characteristic effects of genes on viability8 and on shape of the spermatheca9 in Drosophila seem to suggest that this is the case. Summary.-The tryptophane content of aa Ephestia larvae is higher than that of a+a+ Ephestia larvae in the non-protein fraction and probably also in the protein fraction. In homogenates of isogenic a+a+ and aa homogenates, autolysis proceeds at a faste...

Crosses among the six semispecies of Drosophila paulistorum produce sterile male hybrids. This sterility is caused by an agent which has characteristics of a microorganism. It is pathogenic in a secondary host, the larvae of the Mediterranean meal moth, Ephestia kuehniella, and can be serially passaged in Ephestia, where it is lethal. The agent was passaged back into D. paulistorum, where it in...

larva. In both respects it resembles the effect of docosahexaenoic acid from cod-liver oil. 2. Ascorbic acid, in combination with the saponifiable fraction of wheat-germ oil, has a positive growth effect which is attributed to an antioxidant action. 3. The linoleic acid content of various insect oils has been estimated by testing their effect on the wings of Ephe8tia. Oils from Tenebrio and Eph...

In Ephestia elutella males, mating success is positively correlated with size Experimental manipulation of males demonstrated that this is due to females actively discriminating against small males, the first direct evidence for female mate-choice in moths Furthermore, this female preference is associated with increased fitness in that, by mating with larger males, females are more likely both ...

In a previous publication (Fraenkel & Blewett, 1943) it has been shown that a number of insects which normally live on wholemeal flour or other cereal products grow badly or not at all on flour thoroughly extracted with chloroform unless a sterol, e.g. cholesterol, is added to the diet. For several beetle larvae the diet becomes optimal upon addition of a pure sterol, but for the caterpillars o...

Cautery of the dorsal hindwing in the butterfly, Precis coenia, induces the formation of a concentric colour pattern around the site of injury. The induced pattern is identical in pigmentation to the eyespots that normally develop on this wing surface. This response to cautery also occurs, though much less dramatically, on the ventral forewing. In addition to the peculiar response to cautery, t...