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air comes that will blow a thread in the direction required. As 

 soon as the thread reaches its destination the spider pulls it 

 tight, — ^" though," added Dr. Dallinger, " how it knows I cannot 

 tell, for it is always looking the other way." Then it waits 

 until the thread has hardened, and then proceeds to build a 

 triangle underneath it. In this triangle it puts up its many sided 

 web, connecting every angle with the centre, and filling up all 

 spaces with closely set lines, moistened with gum. A peculiar 

 fact mentioned by the Lecturer was that the spider understood 

 the theory that in a vibrating cord there were nodes, certain 

 points always at rest. It twanged its lines as soon as 

 it covered them with gum, and the gum collected itself on each 

 node in the form of spheres. So what man looked upon as a 

 recent discovery the little spider had known for thousands of 

 years. A feature of this section of the lecture was the way it 

 was illustrated by slides representing the working spider in 

 motion. 



The relation of these facts brought Dr. Dallinger again to 

 the question of whether the spider could think, and, to illustrate 

 his belief that they must have something akin to reasoning power, 

 he gave an instance that had come under his own notice. A 

 spider by the sea found a gully where the wind always blew 

 steadily one way, and it erected its web there. It was just as if 

 it argued that, with such a decided current of air, it was likely 

 that a goodly harvest of flies would be brought down. At the 

 same time, it realised that such a strong current of air would 

 speedily wreck the web, .so it took pains to make the fundamental 

 parts of the structure specially strong. It put in additional 

 buttresses, and even ran skeins on the windward side from the 

 web to the ground, strengthening the fabric in the particular way 

 necessary with the skill of an engineer. How did the spider 

 know that all these extra precautions were essential ? Surely 

 it argued a way out of the difficulty. 



A striking way was chosen by the Lecturer to demonstrate 

 the extreme thinness of a line in a spider's web. It was no 

 good talking about the fraction of an inch, so he threw a 

 picture of a line on the screen. Over that he threw a ruling 

 of lines, drawn on the same scale, each a thousandth part of 

 an inch apart. The difference between the spider's hair and a 

 thousandth of an inch was as the difference between a thread of 

 fine silk and a stout hawser ! 



Some people probably wondered what the spider lived for ; 

 was all this output of ingenuity simply for the degrading object 

 of catching Hies ? He could not answer that question. But it 

 must be remembered that all animals lived by preying upon 

 others. Even the refined ladies and gentlemen before him 

 suffered no qualm of conscience when eating a fowl or rabbit. 



