112 



THE MICROSCOPE AND ITS LESSONS. 



Spinneret of a spider. 



The next part of our object to which I must direct your 

 attention is the said spinneret. At the end of the rounded 



body you will see four 

 or five teat-like protube- 

 rances, and, if we increase 

 our magnifying power, we 

 shall perceive a number of 

 very minute apertures in 

 each. The total number of 

 these spinning-tubes varies 

 greatly, according to the 

 species of- the spider, and 

 the sex and age of the indi- 

 vidual, being more than a 

 thousand in some cases and 



less than a hundred in others.* It is through these 

 microscopical orifices that the persevering creature throws 

 out the hundreds or thousands of liquid lines which, with 

 its wonderful " hand," it twists into that one minute 

 strand, just as the little fibrous bit of flax is made into the 

 bit of string, so that each fine thread that you see in the 

 beautiful net of a garden spider really consists of thou- 

 sands of threadlets of fluid made in that big workshop of 

 its stomach, which, when united by the workman, become 

 comparatively a cable, both in strength and structure. 



But, observe, the net of such a spider as we are now 

 looking at consists of two different kinds of thread, though 

 each thread is formed from the same raw material. Were 

 our specimen uncovered, and the lines fresh from the air, 

 you might put your finger upon those which radiate from 

 the centre to the circumference, and they would not 

 adhere to it ; but were you to do the same with the long 

 spiral line which is supported upon that delicate frame- 

 * Dr. Carpenter. 



