EFFECT OF SACCULIXA UPON FAT METABOLISM OF HOST. 277 
taming diet for some hours, the liver-cells of these, upon 
examination after some time, will be found to contain a 
considerable quantity of fat. Crabs which have not been 
thus fed exhibit none or very little. If one deduces from 
this the immediate dependence of the animal for its fat 
supply on its food-stuffs, then we are naturally led to ask how 
the infected animals exhibit such a constant supply. Moulting 
male and female and breeding females might also be made 
subject to such a question, but we must remember that the 
periods are but temporary with them, and they return again 
to their normal condition, while the infected animal has to 
continue playing the host to the parasite’s Gargautuan 
appetite, though no doubt what is true of the infected 
animal is, to a certain though limited degree, true of the two 
others. 
Is, then, the increased fat in the blood of the infected 
animals the result of an increased activating of fat that 
would otherwise have been stored up ? Or is it due to an 
increased initial supply ? 
I do not think we can resolve this interesting question yet, 
but I am inclined to think that the infected animal obtains 
an abnormal supply of fat. Unfortunately I have not made 
any comparative observations upon the appetite and feeding 
of Inachus, any more than to observe that infected animals 
are as active in obtaining food as are the normal ones. 
Mr. Smith also informs me that he has noticed that the 
former eat very greedily and die much more rapidly than 
uninfected individuals, when starved. Finally, I have reason 
to doubt whether infected crabs live over the summer in 
the Gulf of Naples. 
When observations are carried out to satisfy this question 
it will possibly be discovered that a great mortality of the 
infected ultimately sets in, due to the failure of the crab to 
obtain enough nutrition and reserve material for itself and 
for the parasite. 
