398 RUDIMENTARY, ATROPHIED-, [Chap. XIV. 



" no reference to the future life of the animal, nor has it any adap- 

 " tation to its embryonic condition ; it has solely reference to 

 " ancestral adaptations, it repeats a phase in the development of its 

 " progenitors." 



An organ, serving for two purposes, may become rudimentary or 

 utterly aborted for one, even the more 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 within the 

 ovarium. The pistil consists of a stigma supported on a style ; but 

 in some Compositce, the male florets, which of course cannot be 

 fecundated, have a rudimentary pistil, for it is not crowned with a 

 stigma ; but the style remains well developed and is clothed in the 

 usual manner with hairs, which serve to brush the pollen out of the 

 surrounding and conjoined anthers. Again, an organ may become 

 rudimentary for its proper purpose, and be used for a distinct 

 one : in certain fishes the swim-bladder seems to be rudimentary 

 for its proper function of giving buoyancy, but has become con- 

 verted into a nascent breathing organ or lung. Many similar in- 

 stances could be given. 



Useful organs, however little they may be developed, unless wc 

 have reason to suppose that they were formerly more highly deve- 

 loped, ought not to be considered as rudimentary. They may be 

 in a nascent condition, and in progress towards further develop- 

 ment. Rudimentary organs, on the other hand, are either quite use- 

 less, such as teeth which never cut through the gums, or almost 

 useless, such as the wings of an ostrich, which serve merely as 

 sails. As organs in this condition would formerly, when still less 

 developed, have been of even less use than at present, they cannot 

 formerly have been produced through variation and natural selection, 

 which acts solely by the preservation of useful modifications. They 

 have been partially retained by the power of inheritance, and re- 

 late to a former state of things. It is, however, often difficult to 

 distinguish between rudimentary and nascent organs ; for we can 

 judge only by analogy whether a part is capable of further deve- 

 lopment, in which case alone it deserves to be called nascent. 

 Organs in this condition will always be somewhat rare ; for beings 

 thus provided will commonly have been supplanted by their suc- 

 cessors with the same organ in a more perfect state, and conse- 

 quently will have become long ago extinct. The wing of the 

 penguin is of high service, acting as a fin ; it may, therefore, 

 represent the nascent state of the wing : not that I believe this to 

 be the case ; it is more probably a reduced organ, modified for a new 

 function: the wing of tbj Apteryx, on the other hand, is quite 



