AKACHNIDA. 197 



ensconced in some special hiding-place, situated in a corner of the 

 web, rushes upon her victim, and endeavours to pierce it with 

 her murderous fangs, and thus instil into its body a drop of the 

 subtle venom with which they are armed. Should the imprisoned 

 fly otfer anj-thing like a vigorous resistance, or should its strength 

 appear formidable, she retires for a short time, till it i.s eitlier 

 exhausted by its struggles, or becomes helplessly involved in the 

 meshes of the net ; as soon, however, as she perceives there is 

 nothing to fear, she at once envelopes her prey with coils of silk, so 

 as entirely to conceal it from view. The eggs of these spiders are 

 very numerous, agglutinated into a mass, and enclosed in a volumi- 

 nous cocoon. The radiating lines of these webs are used by opticians 

 in tlie construction of micrometers : they are so elastic, that they 

 may be stretched one-fifth of their length. 



The next group of Sedentary Arachnidans, instead of always walk- 

 ing forwards like the preceding, can walk sideways or backwards, 

 equally well ; they are, therefore, called 



Laterigrades.* These spiders are generally found quite motionless 

 upon vegetables, where they remain with their legs stretched out 

 ready for action. They consti-uct no web, but simply scatter about a 

 few solitary threads to arrest their prey. Their cocoon is round and 

 flat ; they conceal it between leaves, the edges of which they fasten 

 together, and carefully watch it until the eggs are hatched. 



The second division of the race of spiders comprehends 



The Vagabond Arachnidans, as they are called, in contradis- 

 tinction to the preceding, whicli are all sedentary. These spiders 

 make no web, but lie in wait for their prey, which they overtake by 

 running, or by leaping upon it suddenly. They are divided into two 

 sections — 



The Citigrades, or Runners, and the Saltigrades, or Leapers. 



The Citigrades,t called also Wolf Spiders, are to be found on the 

 tops of trees or bushes, where they build a bell-shaped nest, in whicli 

 the females lay their eggs : this nest, or cocoon, they always carry 

 with them when they go to hunt, generally attaching it to their 

 breast. Some of them are frequently seen by the margins of ponds ; 

 sometimes, indeed, they run upon the surface of the water with sur- 

 prising swiftness, and they may be often seen to leap upon flies, and 

 other insects that approach them too closely. One species — 



The Tarantula {Lyeosa Tarentula), so called from the city of 

 Tarentum, in Italy, where it is common, has obtained great celebrity. 

 It is there commonly believed that its bite is very serious, being 

 sometimes fatal, or if not, that it occasions a peculiar malady called 

 Tarentism, only to be cured by music and dancing. Enlightened 

 and judicious persons are of opinion, however, that it is the effect of 

 imagination tliat requires thus to be combated, rather than the 

 venom of the Tarantula. 



The Saltigrade4 ov Leaping Spiders, may frequently 

 be seen upon walls, or in other situations, exposed to the 

 sun. They walk, as it were, by fits and starts, and after 



* Latus, lateris, tlie side ; gradior, I ivalk. 

 t Cito, qulcldy ; gradior, I walk. 

 X Saltus, a hap ; gradior, I wall:. 



