86 PHILOSOPHY OF ZOOLOGY. 



increase or diminution of one organ is accompanied with 

 corresponding changes in all the others. But, when ob- 

 served with attention, the different breeds of our domestic 

 animals exhibit such monstrosities. The size of the body, 

 when compared with the limbs ; the presence or absence of 

 horns ; the length or shortness of fur, are all indications of 

 the deranging influence of domestication. 



The second kind of monstrosity, and undoubtedly the 

 most remarkable, consists in the substitution of function, 

 which sometimes takes place among the organs. In con- 

 sequence of this change, parts arc produced in situations 

 where they do not occur in the healthy state ; while other 

 parts disappear, which are essentially necessary to the har- 

 mony of the whole. Thus with regard to plants, Sir 

 JAMES E. SMITH has observed (and we have witnessed 

 the same appearance,) the double-flowering cherry with the 

 pistil changed into a leaf*. But although the form and 

 function of the organ were thus changed, the new produc- 

 tion was not foreign to the system, as it resembled exactly 

 the common leaves of the branches. The stamens of the 

 rose are frequently converted into petals ; and, in conse- 

 quence of the change, acquire the agreeable perfume pecu- 

 liar to the organ into which they have been metamorphosed. 

 On the other hand, when the stamens of the Meadowsweet, 

 (Spiraea ulmaria,) upon the flower becoming double, change 

 into petals, they lose all the fragrance which they would 

 have possessed as stamens, the petals into which they have 

 passed being scentless. In all these instances of monstro- 

 sity, we observe, that, although an alteration takes place, 

 both in the structure and function of an organ, it is only in 

 exchange for the character of another organ, peculiar to the 

 system to which it belongs. The pistil of the cherry did 



Ihtroduction to Botany, p. 275. 



