238 THE WEB 



to be none the less independent of volition. The design 

 is so much more ambitious than the silk-worm's, the 

 structure so much more elaborate and beautiful, and so 

 closely in accord with the principles of human engineering 

 and cabinet work, that one finds more difficulty in dis- 

 sociating it from the independent ingenuity and conscious 

 skill of the performer. Yet the common garden spider 

 (Epeira diadema) probably acts unconsciously in setting 

 about web-spinning. It does not reflect before putting 

 into operation the spinning mechanism and material 

 which it has inherited from an unseen ancestry. She 

 (for it is the female only that concerns herself with 

 architecture) does not gaze with hungry longing upon the 

 flies disporting themselves in the sunshine, or speculate 

 how, being herself wingless, she can capture those tooth- 

 some flying creatures. Indeed it is almost certain she 

 cannot see them, for the visual powers of most spiders are 

 very feeble, being compensated for by an extraordinary 

 reiinement of the sense of touch. She simply sets to 

 work to apply the [specialised mechanism and material 

 wherewith she is endowed to the purpose with which they 

 are co-ordinate. Although cut off by the period spent as 

 an egg in a cocoon from all parental instruction or ex- 

 ample, she is at no loss for a plan. Innate functional 

 impulse, which is probably the right definition of that 

 which we term 'instinct,' co-ordinate with certain 

 specialised organs, directs the creature to the unconscious 

 performance of certain definite acts without previous 

 practice or experience. First, the foundations are laid, in 

 the shape of lines enclosing the area to be occupied by 

 the web. From this circumference the radii or stays 

 are drawn to the centre, whence the spider works out- 



