406 ON THE ORIGIN OF SPECIES 



Important purpose ; and remain perfectly efficient for 

 the other. Thus in plants, the office of the pistil is to 

 allow the pollen-tubes to reach the ovules protected in 

 the ovarium at its base. The pistil consists of a stigma 

 supported on the style ; but in some Composite, 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 

 developed, and is clothed with hairs as in other Com- 

 posite, 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 nearly rudimentary for its proper function of 

 giving buoyancy, but has become converted into a 

 nascent breathing organ or lung. Other similar 

 instances could be given. 



Organs, however little developed, if of use, should not 

 be called rudimentary ; they cannot properly be said 

 to be in an atrophied condition ; they may be called 

 nascent, and may hereafter be developed to any extent 

 by natural selection. Rudimentary organs, on the other 

 hand, are essentially useless, as teeth which never cut 

 through the gums ; iu a still less developed condition, 

 they would be of still less use. They cannot, therefore, 

 under their present condition, have been formed by 

 natural selection, which acts solely by the preservation 

 of useful modifications ; they have been retained, as 

 we shall see, by inheritance, and relate to a former 

 condition of their possessor. It is difficult to know 

 what are nascent organs ; looking to the future, we 

 cannot of course tell how any part will be developed, 

 and whether it is now nascent ; looking to the past, 

 creatures with an organ in a nascent condition will 

 generally have been supplanted and exterminated 

 by their successors with the organ in a more perfect 

 and developed condition. The wing of the penguin is 

 of high service, and acts as a fin ; it may, therefore, 

 represent the nascent state of the wings of birds ; not 

 that J believe this to be the case, it is more probably a 



