104 
Biology of Pediculus humanus 
some Russian workmen prisoners; he did so in a wind, and, as a prisoner 
undressed before him, he saw a louse blown on to himself from the man 
who stood two feet away from him. Schaefer was wearing a rubber 
coat, consequently the louse slipped off and fell to the ground. He 
frequently saw lice drop from men whilst they removed their clothing, 
and, in consequence of the experience he narrates, always examined men 
afterwards whilst standing to windward of them. 
DISSEMINATION OF LICE BY HOUSE-FLIES. 
Calandruccio (1890, p. 135) states that he has seen capitis and 
corporis conveyed from place to place and person to person by flies, 
the insects being most prevalent in Sicily. Bohne (1915, p. 358) also 
refers to house-flies as carriers x>f lice, in the title of his paper which 
I have been unable to consult. Galli-Valerio (1916, p. 41) put two 
flies in a vessel with lice and subsequently found a louse clinging to a fly. 
Swellengrebel (1916, p. 13) doubts that flieg carry lice about because 
he never saw gorged lice cling to flies that walked upon his arm whilst 
he fed lice thereon; as this author, however, states elsewhere that it 
is the hungry lice that cling promptly to passing objects, his negative 
opinion is somewhat invalidated. I have no doubt that Calandruccio’s 
observation was correct; nevertheless, in the presence of the many 
other ways in which lice are conveyed, it seems that fly carriage can 
but play a very subordinate part and this under particular circum¬ 
stances only. 
Part II. 
METHODS. 
Methods of Raising Lice Experimentally. 
There are various ways of raising lice experimentally, the best being 
those which afford conditions approximating closely to the natural. 
(a) Raising methods whereby unlimited opportunities of 
feeding on man are provided together with normal or 
almost normal surroundings. 
Anthony van Leeuwenhoek (ed. 1807, pp. 163-169) appears to have 
been the first to raise lice with the object of studying their life-history, 
and it seems appropriate to quote his description of how he proceeded 
to do so. 
