Chap. XIII. AND ABOIITED ORGANS. 405 



lliroiighout Nature. It 'would be difficult to name one of the 

 his/her animals in which some part is not in a rudimentary 

 condition. In the mammalia, for instance, the males always 

 possess rudimentary mamma?; in snakes one lobe of the lunj^s 

 is rndimentary ; in birds the "bastard-wing" may safely be 

 considered as a rudimentary digit, and in not a few species the 

 wings cannot be used for ilight or are reduced to a rudiment. 

 AVhat can be more curious than the 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 unliorn calves ? 



Hudimentary organs declare their origin and plain meaning 

 in various wa3's. 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 minute rudiments 

 of membrane, not rarely lying under wing-covers firmly 

 soldered together ; and in this case it is impossible to doubt 

 that the rudiments represent wings. Rudimentary organs 

 sometimes retain tlieir potentiality ; this occasionally occurs 

 with the mamma? of n)ale mammals, for they 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 rudimental, and 

 sometimes well-develojied in individuals of the same species. 

 In certain dicccious ])lants Kolreuter found that by crossing a 

 species, in which the male flowers included a rudiment of a 

 jiistil, with an hermaphrodite species, having of course a Avell- 

 devel()j)ed ])istil, the rudiment in the hybrid ofl'spriiig Avas 

 nuich increased in size ; and this clearly shows that the rudi- 

 mentary and perfect pistils are essentially alike in nature. An 

 animal may ])ossess various parts in a perfect state, and yet 

 they may in one sense be rudimentary, for they are useless: 

 thus tlie tadpole of the connnon Salamander or newt, as Mr. 

 G. II. Lewes remarks, "lias gills, and passes its existence in 

 the water; but the Salamandra atra, which lives high up 

 among the mountains, brings forth its young full-formed. This 

 .•'.nimal never lives in the water. Yet if we open a gravid le- 

 male, we find tadpoles inside her with exquisitt^ly-feathered 

 gills ; and when jilaced in water they swim about like the t^id- 

 ])oles of the water-newt. Obviously, this aquatic organization 

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



