452 RUDIMENTAEY ORGANS. Chap. XIII. 



supported on the style ; but in some Compositae, the 

 male florets, which of course cannot be fecundated, have 

 a pistil, which is in a rudimentary state, for it is not 

 crowned with a stigma ; but the style remains well de- 

 veloped, and is clothed with hairs as in other compo- 

 sitae, for the purpose of brushing the pollen out of the 

 surrounding anthers. Again, an organ may become 

 rudimentary for its proper purpose, and be used for a 

 distinct object : in certain fish the swim-bladder seems 

 to be rudimentary for its proper function of giving buoy- 

 ancy, but has become converted into a nascent breathing 

 organ or lung. Other similar instances could be given. 



Kudimentary organs in the individuals of the same 

 species are very liable to vary in degree of development 

 and in other respects. Moreover, in closely allied 

 species, the degree to which the same organ has 

 been rendered rudimentary occasionally differs much. 

 This latter fact is well exemplified in the state of the 

 wiugs of the female moths in certain groups. Kudi- 

 mentary organs may be utterly aborted; and tins 

 implies, that we find in an animal or plant no trace of 

 an organ, which analogy would lead us to expect to find, 

 and winch is occasionally found in monstrous individuals 

 of the species. Thus in the snapdragon (antirrhinum) 

 we generally do not find a rudiment of a fifth stamen ; 

 but this may sometimes be seen. In tracing the 

 homologies of the same part in different members of a 

 class, nothing is more common, or more necessary, than 

 the use and discovery of rudiments. This is well shown 

 in the drawings given by Owen of the bones of the leg 

 of the horse, ox, and rhinoceros. 



It is an important fact that rudimentary organs, such 

 as teeth in the upper jaws of whales and ruminants, 

 can often be detected in the embryo, but afterwards 

 wholly disappear. It is also, I believe, a universal 



