THE EVOLUTION OF PLANTS. 
28 
true, and are perhaps less often true than is supposed. In any case it 
appears to me they may be subject to explanation. 
Reversions are often a great stumbling-block to many. All the 
cruciferous races have first of all a strong tendency to deteriorate, 
and apparently they would finally revert to originals. If they did so 
revert it would only be natural : conditions would be changed, and 
original conditions ought to produce the original. I should be sur- 
prised, indeed, if such instances could not be found; but nevertheless I 
have failed, after much inquiry, to get any more than a few authentic 
cases of complete reversion, either hybrid or not hybrid. Darwin 
was sceptical upon this very point, and no one ever took more trouble 
than he did to discover facts. Let me quote from his " Origin," 
p. 11 : Having alluded to this subject of reversion, I may here refer 
to a statement often made by naturalists — namely, that our domestic 
varieties when run wild gradually but invariably revert in character to 
the original stocks. Hence it has been argued that no deductions can be 
drawn from domestic races to species in a state of nature. I have in vain 
endeavoured to discover on what decisive facts the above statement has 
so often and so boldly been made. There would be great difficulty in 
proving its truth. ... It would be necessary, in order to prevent the 
effects of intercrossing, that only a single variety should have been 
turned loose in its new home. iSevertheless as our varieties certainly 
do occasionally revert in some of their characters to ancestral forms 
it seems to me not improbable that if we could succeed in naturalising 
or were to cultivate during many generations the several races, for 
instance, of the Cabbage in very poor soil (in which case, however, 
some effect would have to be attributed to the definite action of the 
poor soil) that they would to a large extent, or even wholly, revert to 
the wild original stock. Whether or not the experiment would 
succeed is not of great importance for our line of argument, for by 
the experiment itself the conditions of life are changed." 
I would like to suggest an experiment to anyone who has the means of 
carrying it out. Let the " rogues " from various crops be isolated, and 
see what comes, after many or several generations, when stability or 
equilibrium of some kind is reached. I think it very likely that these 
rogues would not in all cases return by the road along which the 
parents evolved. I think that very likely there would be some permanent 
trace of ancestral garden influence. It would be a good experiment ; 
but, to be fair as to the reversion of a kind, would it not be necessary 
to let the whole crop take its course by crossing together ? To take the 
rogues alone would be selection, and by selection almost any end might be 
obtained. 
I trust now that I carry my argument, and that it is clear that there 
must be an exact parallel between the evolution of plants in the garden 
and the evolution of plants in nature. It is no new idea. Dean Herbert 
years ago believed in the full analogy between garden productions and 
natural productions. It was never a weakness, I think, that Darwin took 
account of garden productions ; indeed, it seems to nie that ho might 
even have deduced his theory from garden productions alone. They all 
fit well into it. 
