64 WILD NEIGHBORS CHAP. 



of expression in a great variety of gestures; as 

 matrimonial advertisements; as egg-holders and 

 incubators ; and finally, as baby carriages, for in 

 all these ways do tails enter into the ministry of 

 limbs to one or another animal. 



And here it is well to broaden out the word 

 "tail" so as to include more posterior appendages 

 than are included in my first strict definition. 

 Nevertheless, we must draw the line inside of 

 popular usage even here. The prolongations of 

 the wings of certain butterflies, for instance, are 

 not "tails," though entomologists term them so in 

 a special sense; nor would it be allowable to in- 

 clude the spinnerets of spiders, nor the stings 

 of bees, nor the ovipositors of many insects, 

 although these sometimes extend in hair-like tubes 

 beyond the tip of the abdomen, nor the apparently 

 similar breathing-tubes of the Ranatra bugs. 



But it is right to speak of the "tail" of the 

 scorpion-fly (Panorpa), which is articulated ex- 

 actly like that of a scorpion, of the skip-jack 

 beetle, and of a few other insects ; while the word 

 is fairly applied to certain worms, to all the 

 swimming crabs, the cuttle-fishes, and even to 

 gasteropod mollusks, wherever the body is length- 

 ened out into a more or less serviceable hinder part. 



Let us take up some of these utilities in their 

 order and illustrate them. What animals, to begin 

 with, employ their tails as a shelter? Well, the 

 great ant-eater does so, for one. The tail of the 



