ORIGIN AND DEVELOPMENT OF INSTINCTS. 189 



ancient times in the East, when flying pigeons was much 

 esteemed. Tumblers have the habit of flying in a close 

 flock to a great height, and as they rise tumbling head over 

 tail. I have bred and flown young birds, which could not 

 possibly have ever seen a tumbler; after a few attempts 

 even they tumbled in the air. Imitation, however, aids the 

 instinct, for all fanciers are agreed that it is highly desirable 

 to fly young birds with first-rate old ones. Still more 

 remarkable are the habits of the Indian sub-breed of tumblers, 

 on which I have given details in a former cliapter, showing 

 that during at least the last 250 years these birds have been 

 known to tumble on the ground, after being slightly shaken, 

 and to continue tumbling until taken up and blown upon. 

 As this breed has gone on so long, the habit can hardly be 

 called a disease. I need scarcely remark that it would be as 

 impossible to teach one kind of pigeon to tumble as to teach 

 another kind to inflate its crop to the enormous size which 

 the pouter pigeon habitually does."* 



This case of the tumblers and pouters is singularly 

 interesting and very apposite to the proposition before us, for 

 not only are the actions utterly useless to the animals them- 

 selves, but they have now become so ingrained into their 

 psychology as to have become severally distinctive of different 

 breeds, and so not distinguish a.ble from true instincts. Tliis 

 extension of an hereditary and useless habit into a distinction 

 of race or type is most important in the present connection. 

 If these cases stood alone they woidd be enough to show that 

 useless habits may become hereditary, and this to an extent 

 which renders them indistinguishable from true instincts.f 



In the Appendix several instructive cases of the same 

 kind will be found, such as that of the Abyssinian pigeon, 

 which, when fired at, " plunges down so as almost to touch 

 the sportsman, and then mounts to an immoderate height ;";[: 

 the biscacha, which " almost invariably collects all sorts of 



* For further particulars on the instinct of tumbling, see Variation of 

 Animal.t and Plants, vol. i, p. 219, and 230. 



I Some years ago the Ratels which were confined in one cage at the 

 Zoological Gardens acquired the apparently useless habit of perpetually 

 tumbling head over heels. If their progeny were to be exposed for a number 

 of generations to similar conditions of life, they would probably develope a 

 true instinct of turning somersaults analogous to that of the tumbler- 

 pigeon. 



J I have frequently noticed a similar propensity in the Lapwing. 



