376 
EXTRACTS FROM FOREIGN PERIODICALS. 
confined to the valueless rules of general classification, by turns wavering, in¬ 
complete or false, once rational and philosophic. Helminthology is in more imme¬ 
diate need of new researches and guides than any other branch of Natural His¬ 
tory.— Annales des Sciences Naturelles. 
3. On a peculiar Human Hace of the Atlas. —M. Guyon, principal 
surgeon to the African army, in a letter to M. Dueeau, announces, that there 
exists at Bougie a native of the interior, a female, supposed to be descended 
from a white tribe of the Auref mountains. This woman is about 26 or 28 years 
of age; has a most agreeable countenance, blue eyes, flaxen hair, beautiful teeth, 
and extremely fine white skin. She is married to the Iman of the Mahometans, 
SiDi Hamed, by whom she has three children who bear a considerable resem¬ 
blance to him. M. Arago adds, that this is not so rare an occurrence as may at 
first be imagined. While going, towards the close of 1808, from Bougie to Al¬ 
giers by land, he saw, in the greater part of the villages of the Kabyles, women 
of all ages who were remarkably white, and who had blue eyes and fair hair. 
Circumstances prevented him from ascertaining their origin.— Bihliotheque Uni- 
verselle de Genece. 
4. Formation of Spiders’ Webs. —We now continue our abstract of M. 
Huges’ paper ‘‘ Sur les AromHdes” in the Annales des Sciences Naturelles^ for 
September and October, 1836. 
The seventh article treats of the secretion of the web. This secretion takes 
place in a glandular mass situated at the posterior part of the abdomen; it is a 
viscous substance, which dries more or less rapidly according to the species, and 
according to the fineness of the thread. This substance is insoluble in water, and 
rain breaks the webs without dissolving them. M. Duges thinks, contrary to 
the opinion of Lister and Latreille —who believe that the threads are forced 
out—that they are simply drawn out by the motion of the body or of the legs. 
This web first serves to construct habitations varying considerably in different 
species. Sometimes the threads alone are employed, sometimes mixed with 
other materials. Some species construct tubes, often very solid; lastly, we know 
the singular lids with which the Mygales (Mygale) protect their dwelling. This 
web serves, in the second place, as every one knows, to form snares for furnishing 
the food of the Spider. The" position of these snares depends on the habits of 
each species. One of the most important points which M. Duges has studied in 
this respect, is the means employed by the Epeiras {Eqjeira) to carry their webs 
to considerable heights, for which purpose they throw into the air long threads, 
which are often attached to points very distant from each other. The author 
has seen, at the extremities of branches, little Spiders, sometimes motionless, 
sometimes rapidly moving their anterior legs. He succeeded in seeing them 
draw from their web-former (filiere and cause to float freely in the air a bundle 
