CARNIVOROUS ARACHNIDA AND MYRIAPODA 



127 



upon the toothed joint which carries it, as the blade of a penknife 

 does upon its handle. Spider poison may be of an extremely 

 virulent kind, as will be seen by the following extract from Semon 

 {quoted from In the Azistralian Bush): — " More poisonous than 

 all the other insects of Australia [the word " insect " is here used 

 in a popular way] ... is a little black spider with a back of vivid 

 red, Latrodectus scelio. This conspicuous spider seems to be 

 everywhere. Though chiefly nocturnal in its habits, it also 

 appears in daytime, imposing on you by a certain calm im- 

 pudence. It takes no trouble whatever to escape or to hide, 

 but, relying on its fatal poison, seems 

 rather to warn you by its vivid colour 

 than to elude your vision by a more 

 modest mien. The bite of this spider 

 is terribly painful, and in its wake we 

 often find paralytic symptoms in the 

 wounded member, its neighbouring 

 •organs, or even the entire body. It is 

 said that grown-up people are sometimes 

 killed by it, and surely this is the most 

 poisonous spider in the world, and the 

 most dangerous arthropod in existence." 

 Undoubtedly, however the most inter- 

 esting and characteristic feature about 

 spiders is found in the spinning organs 

 which they possess. These are in the form of silk-glands, which 

 open by innumerable pores upon the surface of four little teat- 

 like projections placed on the under side of the abdomen (fig. 398). 

 Web-Spinners. — The best-known kinds of spiders construct 

 webs for snaring prey, the most perfect and regular of these con- 

 trivances being the work of the numerous species included under 

 the term "orb spinners", of which the common Cross or Garden 

 Spider [Epeira diademd) (see vol. i, p. 391) may be taken as a 

 good type. Such a web consists of radiating strands which form 

 a. supporting basis, and of a sticky thread which winds round in 

 a spiral way from centre to circumference, and holds fast any 

 unfortunate insect that happens to fly against the snare, which is 

 possessed of a considerable amount of elasticity, so as not to be 

 readily broken. The spider lies in wait for prey in the neigh- 

 bourhood of the web, concealed in some cranny or under a leaf. 



Fig. 398. — Spinnerets of Spider 

 (greatly enlarged) 



