36 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 i the substitution of function, 
which sometimes takes place among the organs. In con- 
sequence of this change, parts are 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 FE. Smiru 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, im conse- 
quence of the change, acquire the agreeable perfume pecu- 
liar to the organ into which they have been metamorphosed. 
On the cther hand, when the stamens of the Meadowsweet, 
(Spirea 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 

Introduction to Botany, p. 275. 
