Vestigial Organs 71 



tion of the upper lip; the serpent's fang is a chan- 

 nelled tooth, and its poison-gland is usually a speciali- 

 zation of one of the salivary glands. At the hind end 

 of a spider's body there is a cluster (usually three 

 pairs) of spinnerets. Each is somewhat like the rose 

 of a watering can and bears numerous minute aper- 

 tures (spinning spools) through which there issues 

 a multiple jet of liquid silk, hardening instantane- 

 ously into a thread. A study of the development of 

 these spinnerets shows that they are transformed 

 abdominal limbs. This is Nature's way; the old 

 becomes the new. The sting of a worker-bee is a 

 transformed ovipositor or egg-laying organ and 

 therefore absent from the drones or males. The milk- 

 glands of mammals, great novelties in their day — 

 what are they but transformations of the common- 

 place glands of the skin ? 



The anatomist also points to the dwindling ves- 

 tigial organs which are to be seen in many an animal's 

 body, like unsounded letters in words, like function- 

 less buttons on our clothes — relics that reveal the 

 past. No teeth cut the gum in the whalebone whales, 

 and yet there are two sets of teeth. Whales have no 

 visible hind-legs, yet many show useless vestiges, 

 buried deep below the surface, with bones, cartilages, 

 and even unmoving muscles. In the inner upper 

 corner of man's eye there is a vestige of the third 

 eyelid, which is large in many mammals and useful 

 for cleaning the front of the eye. It is absent in whales 

 and their relatives, where the window of the eye is 

 continually washed with water; it is vestigial in 



