224 



THE GUIDE TO NATURE 



some parts of their bodies except with 

 the tail. The lion I believe uses his 

 tail for the same purpose. 



Aquatic animals use the tail in swim- 

 ming, and here it serves a very import- 

 ant function. If they have not any — 

 as the seals — • then they must adapt 

 their hind feet to serve the same pur- 

 pose, working them around until they 

 lie almost in the position of a tail. A 

 beaver uses his tail not only in swim- 

 ming but also to carry loads of mud. 



Kangaroos use the tail as a balance 

 weight in leaping. Here it is heavy 

 enough to balance partly the weight 

 of the body in front of the hind legs. 

 Lizards, when they run on the hind 

 legs, do the same thing, as you can see 

 from photographs of the Australian 

 frilled lizard, etc. 



A crocodile uses his tail for swim- 

 ming, and also to strike at his prey. 

 Snakes and other legless animals use 

 it to help them writhe along on the 

 ground. I don't know of any particu- 

 lar usefulness in a tortoise's tail, but 

 it is probably some help to the turtles 

 in swimming. 



Broadly speaking, a tail is an organ 

 that was very necessary and important 

 for the aquatic and amphibious ances- 

 tors from which the higher animals are 

 descended. When they took to terres- 

 trial life and to walking on all fours, 

 the tail became more or less superflu- 

 ous. It tended to dwindle away, and 

 finally to disappear unless it could be 

 made useful for one or another minor 

 purpose. In this case the remains of 

 the tail were adapted for these uses, 

 and very often it is modified into art 

 appendage chiefly ornamental. — W. D. 

 Matthew, American Museum of Natur- 

 al History, New York City. 



A Catalogue of Uses, 



The function of a tail, or any other 

 structure, may be determined by a 

 study of the use to which it is put. A 

 cat uses the tail as a balancer in walk- 

 ing on a narrow branch, as a means of 

 increasing its apparent size when in 

 danger of attack, as an emotional out- 

 let in excitement, and in many other 

 ways. Thus the function of a cat's tail 

 is complex. — Professor H. H. New- 

 man, Chicago University. 



Because It Can't Help It. 



I don't suppose a cat has a tail in 

 order that the tail may perform a cer- 

 tain function. The cat has a tail be- 

 cause it can't help it. Having a tail, it 

 flourishes it about in accordance with 

 its nervous connection. — Chas. B. Da- 

 venport, Cold Snring Harbor, Long Is- 

 land, New York. 



The Tail End a Big Subject. 



Greenwich, Conn. 

 To the Editor : 



In reply of yours of November 8th ; 

 it would take eleven large volumes to 

 discuss the functions of a quadruped's 

 tail. It is commonly believed that the 

 original ancestor of quadrupeds was 

 aquatic and used its tail for a sculling 

 oar ; but, since then, it has taken count- 

 less, difl^erent, additional forms. In 

 the girafife and the elephant as a fly- 

 flapper ; in the South American mon- 

 keys as a fifth hand ; in the alligator as 

 a flail ; in the skunk as a warning to 

 enemies, the same in the rattlesnake. 

 In the flying squirrel as a helm for 

 volplaning ; in the gray squirrel as a 

 parachute to break a dangerous fall ; 

 in the whitetail deer as a signal to the 

 young ones. In the pocupines as a 

 dangerous weapon of ofifense ; in the 

 fox as a muffler for the feet in cold 

 weather; in the cat its service is not 

 very obvious, but it seems to be used 

 as a directive mark when signalling 

 one of its kind from behind, this is 

 achieved partly by the color pattern 

 and partly by the nervous twist of the 

 tip. These are only a few of the uses 

 which occur to me and each illustrates 

 another development of the tail. I 

 would add that in the beaver it is used 

 as a plunging paddle in diving, as well 

 as a signal sounder. 



Yours very truly, 

 Ernest Thompson Seton, 



Redwood poles on the Hanford line 

 of the San Joaquin Light and Power 

 Company in Southern California re- 

 cently had to be replaced because of 

 the activity of the birds in using them 

 as a storehouse for winter food. One 

 pole in particular had been in service 

 17 years and was filled with hundreds 

 of acorns which birds had deposited 

 there. 



