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GENETIC STUDIES ON THE SILKWORM 
VII. ON MOSAICS AND GYNANDROMORPHS. 
In the spring culture of 191 4, I obtained four larvae apparently mosaic 
in morphological character, as the following descriptions show. 
Mosaic 1 (Fig. 68). The pattern was decidedly different on both sides 
of the longitudinal median line, the right being moricaud, and the left normal. 
The boundary was distinct, and the characteristics were not intermingled in 
any way. 
Mosaic 2 (Fig. 69). Normal-patterned 011 both sides, but the skin of the 
left side presented a transparent or "oily" character, as it is commonly called, 
while the right side was of the ordinary opaque white colour. The epi- 
dermal abnormality of the left side was, however, not uniform ; the trans- 
parent areas formed patches surrounded by the normal white portions. 
Mosaic 3 (Figs. 70, 71). On the right side, the anterior half of the body 
(to segment VII) had the ordinary black stripes, in segment VIII the black 
areas predominanted over the white ones, while in the hinder segments the 
pattern was almost perfectly normal. On the left side, the anterior segments 
were practically normal-patterned, provided with a few small scattered black 
spots. From segment VII backwards, especially in the hinder segments, the 
black areas generally predominated over the normal ground colour, though 
their arrangement was very irregular. Nevertheless the unilateral distri- 
bution of the marking is quite obvious, the median line forming the boundary. 
On the ventral surface of the anterior segments as far backward as VII, the 
ventral spots characteristic of S type are \ shaped and confined to the right 
side, while in the hinder segments the spots are complete and equally 
developed on either side of the median line. 
The specimen spoken of was killed and preserved, and the gonads were 
sectioned and mounted for microscopical study, which showed that the right 
gonad was an ovary, while the left was a testis. 
Mosaic 4. The larval pattern was normal, but the two sides of the body 
differed to marked degree in the intensity of their patterns, the right side 
