XXX1l INTRODUCTION. 
of malformation can thus be considered as so many 
reversions to the ancestral form. 
Thus, teratology often serves as an aid in the study 
of morphology in general, and also in that of special 
eroups of plants, and hence may even be of assistance 
in the determination of affinities. In any case the data 
supplied by teratology require to be used with caution 
and in conjunction with those derived from the 
study of development and from analogy. It is even 
possible that some malformations, especially when they 
acquire a permanent nature and become capable of re- 
producing themselves by seed, may be the starting- 
point of new species, as they assuredly are of new races, 
and between a race and a species he would be a bold 
man who would undertake to draw a hard and fast 
line.’ 
Discredit has been cast on teratology because it has 
been incautiously used. At one time it was made to 
prove almost everything; what wonder that by some, 
now-a-days, it is held to prove nothing. True the 
evidence it affords is sometimes negative, often con- 
flicting, but it is so rather from imperfect interpretation 
than from any intrinsic worthlessness. If misused 
the fault lies with the disciple, not with Nature. 
Teratology as a guide to the solution of morpho- 
logical problems has been especially disparaged in 
contrast with organogeny, but unfairly so. There is 
no reason to exalt or to disparage either at the expense 
of the other. Both should receive the attention they 
demand. The study of development shows the primi- 
tive condition and gradual evolution of parts in any 
1 On this subject see a paper of M. Nandin in the ‘Comptes Rendus,’ 
1867, t. 64, pp. 929—933. 
