(x. H. F. Nuttall 
40.') 
none of the numerous lice of all stages that were tested were found to 
survive up to 42|- hours, when maintained under different conditions. 
Living on man a male survived 22 days, a female 17 days, but the 
insects can doubtless live longer. 
The feeding habits of Phthirus recall those of Ixodidae in being 
practically continuous, and, like Boophilus, they stop feeding to moult 
upon the host. After moulting they promptly proceed to feed again, 
shifting but slightly to a fresh feeding ground. On emerging, the young 
larva clasps a single hair and feeds at its base, and after a day or more 
it may clasp two hairs as the later stages do usually. The habit of 
conrinuous feeding explains why the insects die so quickly when removed 
from the host. 
Whilst a brief exposure to light renders the insects restless but does 
not cause them to wander away whilst feeding, a warm body brought 
within their sphere promptly produces great activity in Phthirus when 
it is removed from man. 
REFP^RENCES. 
See Bibliography, pp. 1 et seq., and supplementary Bibliography to follow. 
CORRECTIONS. 
p. 44, lines 1-3. Delete the passages “, as the investigations.latter disease.” and 
substitute “Typhus.” [The investigations of Sergent on relapsing fever did 
not inspire Nicolle’s researches on typhus. The deleted passage was written 
by me under a misapprehension.] 
p. 173, lines 4-5. Delete possibly those of Bacot,” 
