LAMARCK’S THEORY OF EVOLUTION 251 
do every day by suddenly changing, as regards a liv- 
ing being, the circumstances in which it and all the 
individuals of its species are placed. 
“All botanists know that the plants which they 
transplant from their natal spot into gardens for cul- 
tivation there gradually undergo changes which in 
the end render them unrecognizable. Many plants 
naturally very hairy, there become glabrous or nearly 
so; a quantity of those which were procumbent or 
trailing there have erect stems; others lose their 
spines or their thorns; finally, the dimensions of parts 
undergo changes which the circumstances of their new 
situation infallibly produce. This is so well known 
that botanists prefer not to describe them, at least 
unless they are newly cultivated. Is not wheat 
(Triticum sativum) a plant brought by man to the 
state wherein we actually see it, which otherwise I 
could not believe? Who can now say in what place 
its like lives in nature ? 
“To these known facts I will add others still more 
remarkable, and which confirm the view that change 
of circumstances operates to change the parts of 
living organisms. 
“When Ranunculus aquatilts lives in deep water, all 
it can do while growing is to make the end of its stalks 
reach the surface of the water where they flourish. 
Then all the leaves of the plant are finely cut or 
pinked.* If the same plant grows in shallower water 
the growth of its stalks may give them sufficient 
extent for the upper leaves to develop out of the 
water; then its lower leaves only will be divided into 
hair-like joints, while the upper ones will be simple, 
rounded, anda little lobed.t This is not all: when the 
seeds of the same plant fall into some ditch where 
there is only water or. moisture sufficient to make 
* Ranunculus aquaticus capillaceus (Tournef., p. 291). 
t Ranunculus aqguaticus (foliorotundo et capillaceo, ‘ournef., p. 291). 
