THE AMERICAN LOBSTER, 
141 
PARTI COLORED VARIETIES. 
Once in a while a lobster is caught which exhibits a remarkably abnormal colora- 
tion. A lobster which would weigh about 2 pounds was captured near Long Island, 
Portland Harbor, about the year 1886. One half of the body was light yellow, clearly 
defined up to the middle line of the back from the color of the other half, which was 
bright red. There were no spots on the shell. This specimen was exhibited in Boston, 
and afterwards sent to Professor Baird. 
De Kay mentions a similar case (51). He says: 
In June, 1840, I saw in the Fulton Market a lobster which was of two colors, distinctly separated 
by a medial line from the tip of the rostrum to the middle extremity of the plate of the tail. One side 
of the body and all the members were of a light sky-blue, and the other of the usual olivaceous greeu. 
Mr. S. M. Johnson informs me that it is not uncommon to get a lobster in which a 
part of the body is pale red wlnle the rest is normal in color, and that a few years ago 
he had a specimen in which this difference in color was marked by the line running 
through the middle of the back, and that even one-lialf of each ‘‘feeler” was light 
and the other dark. 
Buckland (28) mentions the case of a half “ albino” lobster, which he received in 
May, 1868. He says: 
One side of the barrel was blue and the other was white. The blue turned red on boiling, but 
the white did not There appeared to be no pigment in the white part of the shell. 
Boeck (50, p. 225) says that in 1868 he found a lobster near Haugesund, one half 
of which was of a greenish-black and the other of a liglit-orange color, there being a 
sharp and clearly defined line, which ran lengthwise and divided the shell into two 
parts of equal area. This closely resembles the odd variations which we have just 
noticed in the American species. 
Lovett (128) has described a number of color variations in lobsters from the 
island of Jersey. One which is particularly mentioned — a female with eggs — was of 
a pale lavender color, with a mauve spot on the carapace and with bright blue claws. 
The usual mottled markings ou the sides of the thorax were rather indistinct. He 
speaks also of having observed a full-grown female with eggs of a pale-reddish color, 
with bright antennae. 
Carrington and Lovett have described the great chromatic adaptability of the 
common green crab, Carcinus mcenas {35). 
Boeck says that the European lobster, taken near the mouths of fiords in Norway, 
is lighter in color than is usual, while farther out to sea it becomes much darker. 
Malard thinks that these peculiar color variations are due to the loss of certain 
pigments, in consequence of insufficient light, in the deep grottos or rocky crevices 
where the lobsters may have lived. 
Protective coloration and chromatic adaptability to the immediate environment 
are common to a large number of the Crustacea. It seems to be least observed in 
the highest representatives, the Brachyura. According to Malard this chromatic 
adaptation is effected either (1) chemically, by the modification of pigment under the 
direct action of light, or (2) physiologically, by the action of pigment cells stimulated 
by light, indirectly through the eyes and central nervous system. 
Pouchet has made some interesting observations (see 1 33) ou the variations of color 
in the common shrimp, Palsemon. It was found to be most variable when 3 to 4 cm. in 
