64 
NOTICES OF MEMOIRS'. 
shelter usually become the dwelling-places of small mam- 
malia, which seek shelter from the rains, and these ani- 
mals then serve for the preservation and increase of any 
progeny of the Nigua that may have been left behind by 
the travellers : hence it is that such places often parti- 
cularly abound in Niguas, which attack new-comers in 
great numbers. ✓ 
After accounting for the greater liability of newly-arrived 
strangers to the attack of this insect the author states , that 
the Nigua is a parasite during one period only of its life ; 
for the impregnated female alone bores into the skin of 
warm-blooded animals: the unfecundated females and 
the males do not live parasitically. The dark brown color 
of the contents of the stomach in the animals which are 
found running about indicates that, like the allied fleas, 
they live on blood. 
The consequences of the parasitism of the Nigua are then 
considered and it is admitted that these may, in bad consti- 
tutions, amount to the destructive effects cited by various 
writers. He also remarks on the swelling of the inguinal 
glands observed by TJlloa and Jussieu, and states that it 
occurred in his own person at La Guayra. This swelling 
of the inguinal glands led the authors mentioned to believe 
that a second species exists, but Prof. Karsten is doubtful 
on this point.*' 
When the animal has become quiescent in its dwelling- 
place under the skin it produces little uneasiness unless 
the spot be irritated by pressure or friction, in which case 
# * The compiler of this notice can add his testimony as to the swel- 
ling of the inguinal glands produced by the Nigua ; but it was his im- 
pression that the swelling was aided by the pressure of the boot on the 
wound caused by the Nigua. The animal was extracted, and is now 
in the possession of Mr. Jabez Hogg, F.L.S — R. J. L. G. 
