344 LAMARCK, HIS ETRE AND WORK 
limbs like the others, and consequently a pelvis to 
sustain their hind legs. But here, as elsewhere, that 
which is lacking in them is the result of atrophy 
brought about, at the end of a long time, by the want 
of use of the parts which were useless. 
“If we consider that in the Phoce, where the pelvis 
still exists, this pelvis is impoverished, narrowed, and 
with no projections on the hips, we see that the 
lessened (sédtocre) use of the hind feet of these 
animals must be the cause, and that if this use should 
entirely cease, the hind limbs and even the pelvis 
would in the end disappear. 
‘«The considerations which I have just presented 
may doubtless appear as simple conjectures, because 
it is possible to establish them only on direct and 
positive proofs. But if we pay any attention to the 
observations which I have stated in this work, and if 
then we examine carefully the animals which I have 
mentioned, as also the result of their habits and their 
surroundings, we shall find that these conjectures will 
acquire, after this examination, an eminent proba- 
bility. 
“The following zableau* will facilitate the compre- 
hension of what I have just stated. It will be seen 
that, in my opinion, the animal scale begins at least 
by two special branches, and that in the course of 
its extent some branchlets (vameaux) would seem to 
terminate in certain places. 
“This series of animals beginning with two branches 
where are situated the most imperfect, the first of 
these branches received their existence only by direct 
or spontaneous generation. 
“A strong reason prevents our knowing the changes 
successively brought about which have produced the 
condition in which we observe them; it is because 
we are never witnesses of these changes. Thus we 
see the work when done, but never watching them 
* Reproduced on page 193. 
