to degrees of
heat, light, and moisture, and to the preponderance over others which
certain of the vital functions attain to."

Lamarck is led into the statement that plants have neither actions nor
habits, by his theories about the nervous system and the brain. Plain
matter-of-fact people will prefer the view taken by Buffon, Dr. Darwin,
and, more recently, by Mr. Francis Darwin, that there is no radical
difference between plants and animals.

"The differences between well-nourished and ill-nourished plants become
little by little very noticeable. If individuals, whether animal or
vegetable, are continually ill-fed and exposed to hardships for several
generations, their organization becomes eventually modified, and the
modification is transmitted until a race is formed which is quite
distinct from those descendants of the common parent stock which have
been placed in favourable circumstances.[277] In a dry spring the meagre
and stunted herbage seeds early. When, on the other hand, the spring is
warm but with occasional days of rain, there is an excellent hay-crop.
If, however, any cause perpetuates unfavourable circumstances, plants
will vary correspondingly, first in appearance and general conditions,
and then in several particulars of their actual character, certain
organs having received more development than others, these differences
will in the course of time become hereditary.[278]

"Nature changes a plant or animal's surroundings gradually--man
sometimes does so suddenly. All botanists know that plants vary so
greatly under domestication that in time they become hardly
recognizable. They undergo so much change that botanists do not at all
like describing domesticated varieties. Wheat itself is an example.
Where can wheat be found as a wild plant, unless it have escaped from
some neighbouring cultivation? Where are our cauliflowers, our lettuces,
to be found wild, with the same characters as they possess in our
kitchen gardens?

"The same applies to our domesticated breeds of animals. What a variety
of breeds has not man produced among fowls and pigeons, of which we can
find no undomesticated examples!"[279]

The foregoing remarks on the effects of domestication seem to have been
inspired by those given p. 123 and pp. 168, 169 of this volume.[280]

"Some, doubtless, have changed less than others, owing to their having
undergone a less protracted domestication, and a less degree of change
in climate; nevert