46 RUDIMENTARY ORGANS 



to above structure (as invariable as all other parts 1 ) 

 from their absolute similarity to monstrous cases, 

 where from accident, certain organs are not de- 

 veloped; as infant without arms or fingers with 

 mere stump representing them: teeth represented 

 by mere points of ossification: headless children 

 with mere button, viscera represented by small 

 amorphous masses, &c., the tail by mere stump,- 

 a solid horn by minute hanging one 2 . There is a 

 tendency in all these cases, when life is preserved, 

 for such structures to become hereditary. We see 

 it in tailless dogs and cats. In plants we see this 

 strikingly, in Thyme, in Linuinflavum, stamen in 

 Geranium pyrenaicwm?. Nectaries abort into petals 

 in Columbine (Aquilegia], produced from some acci- 

 dent and then become hereditary, in some cases 

 only when propagated by buds, in other cases by 

 seed. These cases have been produced suddenly 

 by accident in early growth, but it is part of law of 

 growth that when any organ is not used it tends to 

 diminish (duck's wing 4 ?) muscles of dog's ears, (and 

 of) rabbits, muscles wither, arteries grow up. When 

 eye born defective, optic nerve (Tuco Tuco) is atro- 

 phied. As every part whether useful or not (diseases, 

 double flowers) tends to be transmitted to offspring, 

 the origin of abortive organs whether produced at 

 the birth or slowly acquired is easily understood in 

 domestic races of organisms: [a struggle between 

 the atrophy and hereditariness. Abortive organs 

 in domestic races.] There will always be a struggle 

 between atrophy of an organ rendered useless, and 



1 I imagine the meaning to be that abortive organs are specific characters 

 in contrast to monstrosities. 



2 Minute hanging horns are mentioned in the Origin, Ed. i. p. 454, vi. p. 

 625, as occurring in hornless breeds of cattle. 



3 Linum flacum is dimorphic : thyme gynodisecious. It is not clear 

 what point is referred to under Geranium pyrenaicum. 



4 The author's work on duck's wings &c. is in Var. under Dom., Ed. 2, 

 i. p. 299. 



