Chap. XIII. 
KUDIMENTAEY OKGANS. 
451 
rudiments represent wings. Eudimentary organs some¬ 
times retain their potentiality, and are merely not deve¬ 
loped : this seems to be the case with the mammae of 
male mammals, for many instances are on record of 
these organs having become well developed in full-grown 
males, and having secreted milk. So again there are 
normally four developed and two rudimentary teats in 
the udders of the genus Bos, but in our domestic 
cows the two sometimes become developed and give 
milk. In plants of the same species the petals some¬ 
times occur as mere rudiments, and sometimes in a well- 
developed state. In plants with separated sexes, the 
male flowers often have a rudiment of a pistil; and 
Kolreuter found that by crossing such male plants with 
an hermaphrodite species, the rudiment of the pistil in 
the hybrid offspring was much increased in size ; and 
this shows that the rudiment and the perfect pistil are 
essentially alike in nature. 
An organ serving for two purposes, may become rudi¬ 
mentary 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 protected in 
the ovarium at its base. The pistil consists of a stigma 
supported on the style; but in some Compositsc, 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- 
sit 80 , 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 
