THE AMERICAN LOBSTER 
175 
green. Bright yellow-green areas are noticeable on the abdominal terga as before, and 
upon the hinder portion of the carapace. There is some brown pigment on the large 
chelae and tail-fan. In the fourth variety (fig. 36), the abdomen and chelae are rich 
reddish-brown, with light peacock-green on the terga of the abdominal rings, as is 
commonly seen, and on the carapace next to the abdomen. The rest of the carapace is 
greenish-brown. In this and all earlier stages the color of the carapace is partly due 
to that of the internal organs, especially to the alimentary tract and gastric glands. 
The following notes illustrate the changes which individual larvae undergo, with 
reference to molting and surrounding conditions. A fourth larva raised from the egg, 
when examined on July 13, was decidedly bluish. The whole animal was quite trans- 
lucent, the heart and yellowish “liver” showing plainly through the shell. The claws 
and body were sky-blue, due, as in the first larva, to the blood pigment. The brown 
and yellow chromatophores were contracted to such an extent as to have no appreciable 
effect upon the general color pattern. Two days later the carapace was greenish and 
the chelae dark brown. On July 17 the colors w T ere deeper; on the 19th the general 
cast of color was dark bluish-green; reddish-brown on the abdomen and chelae. On 
July 21, when the animal was nearly ready to molt, the carapace was bluish-green, the 
abdomen and chelae brownish-red. Four days later, July 25, this animal molted to the 
fifth stage. The fifth larva was dark olive, tinged with brown on the abdomen and chelae. 
A larva which molted July 11 to the fourth stage was pale, and apparently 
almost devoid of pigment. The internal organs were plainly visible. There was a 
delicate wash of brown on the abdomen, tail-fan, and chehe. The microscope showed 
that the closed chromatophores were very small. 
Another larva, 13.1 mm. long, which was raised from the egg, had on July 6 the 
usual mixture of brown and green pigments. On July 15 the animal was very dark 
brown, excepting the carapace, which had a metallic green luster. The large chehe 
are tipped with white or cream color, and there is a large light patch on the outer side 
of the hinder end of the exopodite of the uropod. Fainter and smaller whitish areas 
occur on the pleura of the first abdominal ring. This larva molted about August 3 to 
the fifth stage; color, reddish brown. 
Rarely is a larva seen which is reddisli-orauge, the blue and brown pigments 
being almost completely obscured. The pigments of the eye are similar to those of 
the earlier stages. 
In a larva of 14 mm. long, observed July 25, the carapace was of the usual greenish- 
brown cast, with three light- greenish spots on each side — a very small spot behind 
the eye, a smaller one below this, and a larger one farther back below the cervical 
groove. These are the first traces of very characteristic areas, which I shall call 
“tendon marks,” upon the skeleton of all later stages, and mark the places where 
certain muscles are attached to the integument. The significance of these color 
changes will be considered later on. (See p. 135.) 
A fourth larva, which was caught at the surface near the Fish Commission wharf 
on a very bright day (July 25, 1891), was similar in color to some of those already 
described. The thorax w-as green, brightest posteriorly; the chelae and abdomen dark 
reddish-brown; a brilliant light-green area appeared on the tergurn of the third and 
fourth abdominal segments. 
On August 10 I examined a number of lobsters in the fourth, fifth, and sixth 
stages, which had been kept in glass jars and fed upon meat. Many of these were so 
