EFFECT OF SACCULINA UPON FAT METABOLISM OF HOST. 275 
condition of the liver as a basis of comparison between 
the breeding females and infected animals of both sexes, 
and I make such a comparison with due regard to this quali- 
fication. Indeed, if we are not prepared to allow such a 
comparison, at all events we are left with yet another 
characteristic in common between the adult female and the 
infected crabs, viz. the loss of colour in the liver. 
It is a curious point to observe that in the normal male 
the blootl, as the summer approaches, loses its lipochrome, 
while the liver tends to become pale. A possible interpreta- 
tion of this, though as yet quite unverified in fact, is, that 
the liver, though containing fat, has not yet received the 
appropriate stimulus (e.g. the moult of infection) to liberate 
its contents into the blood. Finally, I may say that the 
insufficiency of our knowledge of the function of the “ ferment 
cells ” relegates much of this reasoning to the region of 
tentative hypothesis. 
II T. The Nature and Function of the Lipochrome of 
Inachus. 
We have hitherto regarded the two lipochromes, pink 
and yellow, as one, and have indicated their relation to the 
development of fat. It now remains to state the little tli at 
seems to be justified from my observations as to their nature 
and function. 
It has been observed above that, though clearly distin- 
guishable as pink and yellow in their more pronounced 
stages, they tend to merge insensibly into each other. Hut 
so much is clear, that a rich orange yellow characterises the 
blood-pigment of the female in the breeding season, and a 
pink shade the male and female at the moult and under the 
influence of Sacculina. It may possibly be of interest from the 
point of view of “heterozygosis” to remark that the male 
occasionally exhibits a pure yellow lipochrome in the blood. 
With regard to the moulting animals, the lipochrome may 
be traced from the blood into the skin of the joints and 
