Pomona College, Claremont, California 149 
female and male so equally and uniformly during the first four or 
five moults and withTrochosa during the first six or seven moults, 
that one is scarcely able to distinguish the sex. Among orb weavers 
generally, and in spiders of various tribes observed, the change in 
color is not decided in the male; that is, the young male carries the 
typical color and general shape of the adult female, the younglings 
of both sexes after the initial moults resemble each other perfectly, 
and tend to resemble the adult female. Though the young male of 
Dictyna p. bears a close resemblance in color and pattern to the 
adult female. He concludes that when the adult male is more con- 
spicuous than the adult female, the young of both sexes take after 
the latter in form and color. On the contrary when the female is 
more conspicuous the young follow the more modest colors of the 
male, especially in the earlier moults. When the adult sexes resem- 
ble each other the young of both favor the common type.” 
6. The Adult Thomisidae change color and color pattern 
according to their environment, but this is not so true of the imma- 
ture. 
7. (a) An adult spider whose ground color is brown, has young 
whose first ground color is yellow and then later becomes suffused 
with brown. 
(b) The young of an adult whose ground color is green, is first 
yellow and then green. 
(c) A gray spider has gray young. 
(d) The black of all spiders, except Latrodectus mactans, is 
brown black, not pure black. 
(e) The only color found in spiders, due to refracted light, was 
in the mandibles of Attide. 
If the color sequences of all spiders were known, it would be an 
easy task to determine any immature form, but even without this 
knowledge it is not impossible to determine to what large family or 
group an immature specimen belongs. Three things have to be 
considered in the determination: First, that the young resemble the 
adult in form; second, that the eye placement of the immature is the 
same as that of its adult; third, the ground color of the immature is 
the same as in the adult. In this last it may lack in intensity or differ 
in shade. This may not be true of the first color, but remains true 
for the second moult. 
