XXX1V INTRODUCTION. 
been already said to prove that there is no intrinsic 
difference between the laws of growth in the two 
cases. As our knowledge increases we shall be 
enabled to ascertain approximately of what extent 
of variation a given form is capable, under given con- 
ditions, and to refer all formations now considered 
anomalous to a few well-defined forms. Already 
teratology has done much towards showing the 
erroneous nature of many morphological statements 
that still pass current in our text-books, though their 
fallacy has been demonstrated again and again. Thus 
organs are said to be fused which were never separate, 
disjunctions and separations are assigned to parts that 
were never joined, adhesions and cohesions are spoken 
of in cases where, from the nature of things, neither 
adhesion nor cohesion could have existed. Some organs 
are said to be atrophied which were never larger and 
more fully developed than they now are, and so on. 
So long as these expressions are used in a merely 
conventional sense and for purposes of artificial classi- 
fication or convenience, well and good, but let us not 
delude ourselves that we are thus contributing to 
the philosophical study either of the conformation 
of plants or of the affinities existing between them. 
What hope is there that we shall ever gain clear con- 
ceptions as to the former, as long as we tie ourselves 
down to formulas which are the expressions of facts as 
they appear to be, rather than as they really are? 
What chance is there of our attaining to comprehensive 
and accurate views of the genealogy and affinities of 
plants as long as we are restricted by false notions as 
to the conformation and mutual relation of their parts 
 Itis probable that many terms and expressions calculated to mislead 
