Order 1. PULMOXARIA. 455 



these Spiders, not having a sufficient supply of silk, merely emit single threads, such, for instance, as 

 those made by young LycosEe, which are to be seen in great abundance crossing from ridge to ridge 

 in cultivated lands, when they reflect the sun's rays. When chemically analyzed, they are found to 

 exhibit precisely the same characters as the silk of Spiders, and are, therefore, not formed in the air, 

 as has been conjectured by Lamarck. Gloves and stockings have been made with spiders' silk ; but 

 these attempts, not being capable of a general application, and being subject to great difficulties, are 

 more curious than useful. The material is, however, far more important for the Spiders tliemselves. 

 It is by its means that the sedentary species, or those which do not chase after their prey, construct 

 their webs of a more or less firm texture, capable, in some exotic species, of holding small birds, and 

 of which the forms and positions vary according to the habits peculiar to each species, and which are so 

 many snares in which the insects which serve them for food are captured. Scarcely is one caught 

 by the hooks of the tarsi, than the Spider, sometimes placed in the centre of its web, or in a cell near 

 one of its angles, darts forth, approaches the insect, uses all its eflForts to wound the captive vrith its 

 murderous darts, and to discharge into the wound an active poison. When it opposes too strong a 

 resistance, and a struggle may be dangerous to the Spider, the latter retires for a time, until it has 

 lost its strength, and becomes still more entangled in its ineffectual efforts to escape, when, there 

 being no longer cause for alarm, the Spider returns, and endeavours to twirl it round, weaving, at the 

 same time, around it a strong silken web, in which it is sometimes entirely encased. 



Lister states that the Spiders discharge their threads in the same manner as the Porcupine is fabu- 

 lously asserted to do, with this difference, that the threads of the Spider remain attached to its body. 

 This fact has been considered impossible. We have, however, seen the threads issue from the nipples 

 of some Thomisi, extending in a straight line, and forming moveable rays when the animal moves them 

 circularly. Another use of silk common to all female Spiders is, for the construction of cocoons 

 destined for the inclosure of the eggs. The contexture and the form of these cocoons are varied ac- 

 cording to the habits of the various races of Spiders. They are generally spheroid ; some have the 

 shape of a cap or a flat sphere ; some are placed on a peduncle, and others are terminated by a club. 

 Other matters, such as earth, leaves, &c., sometimes cover them, or at least partially ; a finer tissue 

 often envelops the eggs in the inside, where they are loose or agglutinated together, and are more oi 

 less numerous. [Then follo^^'s a long passage relative to the presumed use of the male palpi as organs 

 of generation, to which a note is added, that they may at least be considered as exciting organs.] From 

 the experiments of Audebert, it appears that a single fecundation is sufficient for several successive 

 generations ; but, as in all insects and other analogous classes, the eggs are sterile if the sexes have 

 not coupled. The first-laid eggs are hatched before the end of the autumn ; the others remain through 

 the winter unchanged. It has been observed that the females of some species of Lycosae tear open their 

 egg-cases when the young are ready to come forth, and the young, when first hatched, mount upon the 

 back of their parent, where they remain for a considerable time. Other female Spiders carry their 

 cocoons beneath the breast, or station themselves near them to act as guards. The two fore-legs are 

 not developed in the young of some species until some days after their birth. Others, during this 

 period, assemble themselves in society, appearing to spin a common envelope. Their colours are at 

 this period more uniform, so that the inexperienced naturalist is liable to err in multiplying the num- 

 ber of species. M. Saint Fargeau has observed that these animals possess, as well as the Crabs, the 

 power of renewing their lost limbs. 



I have ascertained that a single bite of a moderate-sized spider will kill a house-fly in a few minutes. 

 It is further certain that the bite of the great American Spiders, called Crab Spiders, belonging to the 

 genus Mygale, kill small vertebrated animals, such as humming birds, pigeons*, &c., and may even 

 cause in Man a violent increase of fever ; even the wound of some of our southern [French] species 

 has proved fatal. Without believing all the fables of Baglivi and others as to the powers of the Tai antula, 

 we may dread the bite of the larger species of Spiders, especially those of warm climates. Some 

 species of Sand-wasps (genus Sphex, Linn.) seize upon Spiders, which they wound, and then bury in 

 burrows, in which they also deposit their eggs, in order that they may serve as food for the young 

 when hatched. The majority of these animals die in the autumn, but others live through several 

 seasons, including Mygale, Lycosa, and probably others. Although Pliny asserts that the Phalangiums 



• [See the supplemental observatiuns on the genus Mygale, as to the origin uf this wiHely-spreari error. J 



