488 COMPENSATION. 
conformation, these co-relationships would have been 
rendered much more evident. A hundred different 
plants, for instance, may be named in any particular list, 
of which fifty shall be of one type of structure, and the 
remainder of another. And the co-relative changes 
in each fifty may appear to be evenly balanced, but 
so far is this from beimg the case, that the frequency 
of the occurrence of a particular change, in one species 
in the list, may be so great as far to exceed the instances 
of its manifestation in all the rest put together. This 
difficulty is only very partially obviated by the addition 
of the * to signify especial frequency of occurrence of 
any given malformation im the plants to whose names 
it is affixed. 
Compensation—But little further need be said on this 
head. An atrophied condition of one part is generally 
associated with an hypertrophied condition of another, 
and scarcely a change takes place in one direction, but 
it is associated with an inverse alteration in some other. 
This principle is not universal, and its application must 
not be unduly strained. It requires specially to be 
considered in reference to differences in the degree or 
kind of functional activity exercised by the organs 
implicated--points beyond the scope of the present 
volume. 
Teratology and classification Lastly, there remain to 
be mentioned. the bearings of teratology on systematic. 
botany. There are those who would entirely exclude 
teratology from such matters. It may be ex- 
pedient to do so when the object sought is one of 
convenience and facility of determination only, but 
when broader considerations are concerned, teratology 
must no more be banished than variation. In most 
instances the one differs but in degree from the other. 
If variation affords aid in our speculations as to the 
affinities and genealogical descent of species and other 
groups, so does teratology, and in a far higher degree. 
