RUDIMENTARY ORGANS 265 



name one of tlie higher animals in which some part or 

 other is not in a rudimentary condition. In the mam- 

 malia, for instance, the males possess rudimentary mam- 

 m£e; in snakes one lobe of the lungs is rudimentary; in 

 birds the "bastard-wing" may safely be considered as a 

 rudimentary digit, and in some species the whole wing is 

 so far rudimentary that it cannot be used for flight. What 

 can be more curious than tne presence of teeth in fetal 

 whales, which when grown up have not a tooth in their 

 heads; or the teeth, which never cut through the gums, 

 in the upper jaws of unborn calves? 



Eudimentary organs plainly declare their origin and 

 meaning in various ways. There are beetles belonging 

 to closely allied species, or even to the same identical 

 species, which have either full-sized and perfect wings, 

 or mere rudiments of membrane, which not rarely lie 

 under wing- covers firmly soldered together; and in these 

 cases it is impossible to doubt that the rudiments rep- 

 resent wings. Rudimentary organs sometimes retain their 

 potentiality: this occasionally occurs with the mammse of 

 male mammals, which have been known to become well 

 developed and to secrete milk. So again, in the udders 

 in the genus Bos, there are normally four developed and 

 two rudimentary teats; but the latter in our domestic 

 cows sometimes become well developed and yield milk. 

 In regard to plants the petals are sometimes rudimentary, 

 and sometimes well-developed in the individuals of the 

 same species. In certain plants having separated sexes 

 Kcilreuter found that by crossing a species, in which the 

 male flowers included a rudiment of a pistil, with a 

 hermaphrodite species, having of course a well -developed 

 pistil, the rudiment in the hybrid offspring was much in- 



