ANIMAL LIFE AND THE MICROSCOPE 



bark and stones; the crab spiders usually brightly 

 ; coloured little fellows with the habit of living in 

 flowers; the little money-spinners and the harvest- 

 men; these last are not true spiders but they are 

 none the less interesting, they are the small-bodied, 

 very long legged creatures which occasionally find 

 their way into our houses. 



Having taken our fill of the spiders' feet we may 



well turn our attention to their heads. If we have 



caught a spider in the act of killing a struggling 



fly, it must have struck us that one bite from the 



I spider is sufficient to kill its victim. Let us see if 



■ we can find the jaws which so quickly bring death 



1 even to large insects. We shall require a steady 



e hand and some little skill to examine them properly 



0, but the task is not beyond our powers. Having 



h' killed our spider we must snip off its head, place it 



rs on a slide and examine it with a low magnification. 



Looking straight at the face, we can plainly see the 



oii sharply pointed, hinged jaws; in nearly all spiders 



ict they work from side to side and they can be closed 



js on their hinges like pocket knives. With a pair of 



del mounted needles and two steady hands, let us dis- 



the sect the head of our spider, so that we obtain one 



ulrof the jaws quite free from its surroundings. At 



the base we shall find a little sac, the poison gland, 



itjiand if we now magnify the jaw much more highly 



we shall observe a tiny hole very near the tip. 



When the spider has grasped her prey in her jaws 



he causes the poison from the poison glands to pass 



til to the body of her victim, by way of the little 



115 



