9G 
EXTRACTS FROM FOREIGN PERIODICALS. 
and will not, unless specially conveyed by donation, form part of the general 
property, until the funds shall be sufficient to pay off the shareholders. 
The duplicates will, at first, be distributed among the shareholders only, and, 
in addition to the ordinary privileges of personal admission to housed collections, 
museum, library, and meetings, they will be entitled to give a certain number of 
free admissions daily to strangers. 
EXTRACTS FROM THE FOREIGN PERIODICALS. 
Zoology. 
i. The Chigger ' Fh ^ PL^Pulex penetrans). —M. Duges, of Montpellier, has 
lately published an interesting account of this insect in the Annates des Sci¬ 
ences naturelles. In writing his former memoir on the genus Pulex, in the 
sam.e Journal, he knew nothing with certainty of the above species; reduced 
to accounts which could be of little value, and deceived by a caudal appen¬ 
dage which is probably nothing more than the penis of the male, he expected 
it would form a genus by itself. Actual observations made upon specimens 
preserved in spirits, have, however, convinced him, that this insect only differs 
from the rest of the genus in slight particulars, and especially in its habits, 
which would not warrant the formation of a new genus. After noting some 
particulars relative to the Fleas which infest the clothes of the bathers on the 
shores of the Mediterranean in such numbers, and after extracting some ob¬ 
servations on P. penetrans^ from M. Aug. de St. Hilaire’s Voyage an Bresilf 
we find some further remarks on the latter insect. The author ascertained, 
that the Chigger Flea settles between the epidermis and the cuticle, by cutting 
through the latter. It proceeds then by increasing the small hole which 
the animal has already made in the skin, and this may be done without the 
person on whom the insect operates feeling any pain, or losing even the 
smallest quantity of blood. The insects generally lodge themselves under the 
nails; M. Saltzmann has had them on the soles of the feet and the palms of 
the hands. In the specimens preserved in spirits, M. D. did not find the 
rings of the abdomen which pass through the hole in the epidermis, protruding 
from the skin, and making the vermicular motion spoken of by M. de St. 
Hilaire. Perhaps the latter only takes place at the period immediately fol¬ 
lowing the incision of the insect. In the individuals examined by M. D., the 
abdomen appeared entirely membranous; but in the region of the anus cor¬ 
responding to the opening of the epidermis under which the animal was 
lodged, an orifice, surrounded by plates, was found. This circumstance con- 
