STUDIES IX THE EXPERIMENTAL ANALYSIS OF SEX. 287 
;femal^ characters, despite the partial destruction of the Ovary, 
wliich is deprived of- its nutrition. 
< For some time an attempt has been made to find the 
underlying physiological counterpart of these morphological 
changes, and it can now be claimed that at any rate in some 
particulars the feminising influence of the, activity of the 
'Sacculina roots has been traced to its physiological cause. 
We can summarise the physiological action of Sacculiua in 
the statement that the roots of the parasite act the same part 
in the metabolism of the infected crabs hs the ovary of a 
normal female crab, by taking up from the blood the same 
fatty material as is required by the ovary, and by stimulating 
the metabolic organ, viz. the liver, to an increased elaboration 
of fat. So far we are on certain ground, but in other respects 
we can trace the feminising action of the parasite, though the 
interpretation of these results is not so simple. Thus, in the 
normal female, maturing its ovaries, it has been shown that 
the blood becomes progressively charged with lutein and fat 
which are deposited in the ovary, until finally at the shedding 
of the eggs the blood becomes colourless again. In Saccu- 
linised Carcinus the blood does not become charged with 
lutein and fat, but the liver is always coloured with the 
lutein and so are the Sacculina roots, showing that a trans- 
ference of these materials has occurred, perhaps so rapidly 
that their presence in the blood cannot be detected. In 
Sacculinised Inachus the red lipochrome tetronerythrin 
appears frequently in the blood, but here it is not known 
whether this pigment is accompanied by fat and lutein which 
it masks — an occurrence which is often found towards the end 
of maturity in a normal female. 
In regard to moulting in Carcinus, we find that the periodic 
heaping up of glycogen in the liver and skin preparatory to 
a moult does not occur in Sacculinised crabs, these individuals 
never moulting and never growing after once the Sacculina 
has come to the exterior. We may say, therefore, that there 
is an inhibition of the glycogenic function both in relation to 
growth and moulting in infected individuals. It is probable 
