112 
Biology of Pediculus humanus 
times once a day, they do not thrive so well as when they feed at 
their list. The rare feedings cause the lice to gorge themselves in an 
abnormal manner, which leads to a certain mortality, nevertheless 
they have remarkable powers of adapting themselves to such artificial 
conditions. 
« 
Attempts to Raise Lice by Feeding them on Animals, with Notes on 
their Occasional Occurrence on Animals. 
In view of experimental work on typhus and relapsing fever, and 
the difficulties involved in finding persons willing to submit themselves 
to the discomfort of being bitten by lice, even when these are not 
suspected as possible carriers of infection, it is natural that repeated 
attempts should have been made to r^ise the insects by trying if they 
would feed upon different animals. 
That human pediculi occasionally stray on to other animals, is well 
known. According to Cummings (1915) the British Museum possesses 
specimens collected from monkeys, cats, dogs and pigs, all of which, 
we may add, may live in close contact with man. I have even seen 
specimens stated to have been collected on a fowl. This occurrence 
of human pediculi on different animals, has, however, no more signifi¬ 
cance than if they were found on a hearthrug or chair unless it can be 
shown that they breed upon other hosts than man. Muller (1915, p. 52) 
investigated the reported occurrence of corporis upon horses, but on 
several occasions found that Haematopinus asini had been mistaken for 
the human parasite; on the other hand I possess both capitis and corporis 
collected for me from a pony in Szechuen, Western China; I have, 
however, little doubt but that they emanated from lousy native riders. 
According to a review of a paper by Noeller (1916, p. 778), which I 
have been unable to consult in the original, it would appear that this 
author found human lice “capable of living and breeding on pigs”; 
it remains to be seen if this is true or not. With this questionable 
exception, then, there is no record of human pediculi having been raised 
successfully on animals. 
In the following list, I have grouped the various observations in the 
order of the animals upon which attempts have been made to feed lice 
by different authors: 
