258 
GEOFFKEY SMITH. 
immediately after a moult and approach the period when 
a new ecdysis may be expected, the chitinous integument 
changes from green to yellowish brown or red, especially on 
tlie under surface and in the region of the joints. In the 
male these changes are particularly striking, especially in 
large males, where the skin at the joints of the appendages 
becomes bright red. There can be no doubt from the 
sequence of events that this red pigment which appears 
between the moults at the joints of the male’s limbs is 
derived from the pink lipochrome in the blood. As to the 
function of the red deposit, it is difficult to speculate ; it may 
be merely in the nature of an excretion to be got rid of 
at the ensuing moult, but it is quite possible that it serves as 
a sexual ornament, since the brilliant red colour of the under- 
side of the male is fully displayed wheu he rears himself in 
combat with other males or in approaching an individual of 
the opposite sex. The appearance of the lipochrome in the 
male’s blood is, however, an index of a greater fat transport, 
and it is probable that at the period preceding a moult 
reserve material is in requisition for the formation of the new 
skin underneath. We can understand to some extent in this 
case why the lipochrome, passively accompanying the fat, 
should appear as a deposit at the surface of the animal’s 
body. 
By following the changes in the blood as the various 
phases of moulting and reproduction follow one another 
throughout the year it has been possible to establish the 
conclusions given above. We have now to take a similar 
survey of the changes occurring in the so-called liver, the 
great metabolic organ of the Crustacean. 
There can be no doubt that Heim was correct in supposing 
that the liver was the seat of origin of the lipochrome. 
Large quantities of fat and lipochrome can always be 
abstracted from the liver, and sections of the liver stained 
with osmic acid or Sudan III reveal that the greater number 
of the liver cells are more, or less crowded with fat-globules, 
which form by far the most important part of the reserve 
