Abstract
The markings of the newly hatched larvae were studied from the physiological genetical point of view, using about forty mutants.
The color tone of the “A” marking (the Ist segment) becomes decreased and less distinct under the influence of the oily gene. The segments, which receive the effect of the E allelomorphic genes in the larval stage, appear more deeply black than other segments. The yellow substance (xanthopterin B) in lemon (lem) is already recognized at this period.
Histology of the “A” marking and the black or brown parts clarifies that, in these regions, the black or brown pigments are deposited in the nodules and the primary cuticle layer. The distribution of the nodules are regular and dense in these pigmented parts, but irregular and scattered in others (the 4th segment etc.).
Some experiments were made concerning melanosis as an approach to the analysis of the pigmentation. Melanosis is clearly demonstrated in the blastokinesis and just after hatching, except for the blushed eggs. As a substrate relation, tyrosine and phenylalanine are found abundantly in the eggs, but nearly disappeared on hatching (by means of the paper chromatography).
On examining with the spectrophotometer, the black and brown pigments mentioned here are identified as melanin.
