TEGENERIA MEDICINALIS. 



armed with two hooks. The pulmonary sacs are placed 

 near the base of the abdomen, and indicated externally by a 

 brownish or whitish spot. They are now arranged into 

 groups or families, according to the arrangement of the man- 

 dibles and eyes, which correspond very remarkably with 

 their respective modes of life. 



The spider being formed for a life of rapacity, and incapa- 

 ble of living on any other than insect food, all its habits are 

 calculated to deceive and surprise ; it spreads toils to entangle 

 its prey; it is endued with patience to expect its approach, 

 and possesses power sufficient to destroy it when captured. 

 For the purpose of constructing its web, Nature has supplied 

 the spider with a large quantity of glutinous matter within 

 its body, and with five papillae or teats for spinning it into 

 thread.' This substance is contained in a little bag, and at 

 first sight resembles soft glue, but when more accurately ex- 

 amined is found twisted into many coils of an agate color, 

 and on breaking it the contents may easily be extended into 

 threads from the tenacity of the substance, not from those 

 threads being already formed. The machine by which wire 

 is drawn will furnish some idea of the manner in which this 

 creature forms the thread of its little net ; the orifices of the 

 five teats through which the thread is drawn contracting or 

 dilating at pleasure. The threads which are seen, and which 

 appear- so fine, are, notwithstanding, composed of five joined 

 together, and these are repeatedly doubled as the work pro- 

 ceeds. When a house or a common spider is about to form 

 a web, it first selects some commodious and secure spot, 

 where insects appear to be in sufficient abundance. It then 

 distils a small drop of its glutinous liquor, which is very 

 tenacious, and, creeping up the wall, and joining its thread as 

 it proceeds, darts itself in a very surprising manner to the 

 opposite station, where the other end of the web is to be 

 fastened. The first thread thus spun, drawn tight, and fixed 

 at each end, the spider runs on it, backwards and forwards, 

 still assiduously employed in doubling and strengthening it, 

 as on its force depends the strength and stability of the whole. 

 The scaffolding being thus completed, the spider draws a 

 number of threads parallel to the first in the same manner, 

 and then crosses them with others ; the adhesive substance 

 of which they are formed serving to bind them together 

 when newly spun. After this operation, the wary architect 



3 



