208 
MEMOIR OP DAUBENTON. 
existed. He had the pleasure of verifying this conjec- 
ture, when, thirty years after, the Museum obtained 
the skeleton of the giraffe which is now preserved 
there. 
Before his time, very vague ideas prevailed on the 
differences between Man and the Orang-outang. Some 
regarded the latter as a wild man ; others alleged that 
it was man degenerated, and that it is his nature to go 
on four feet. Daubenton proved, by an ingenuous and 
decisive observation on the articulation of the head, 
that Man could never walk otherwise than on two feet, 
nor the Orang-outang otherwise than on four. 
In vegetable physiology, he was the first who called 
attention to the fact, that all trees do not increase by 
exterior and concentric layers. The trunk of a palm, 
which he examined, showed none of these layers ; 
roused by this observation, he perceived, that the in- 
crease of this tree takes place by the prolongation of 
the fibres from the centre, which develop themselves in 
leaves. He explained by this, why the trunk of a palm 
does not grow thicker as it increases in age, and why it 
is of the same size throughout its whole length ; but he 
did not push his researches further. M. Desfontaines, 
who had observed the same thing a long while before, 
has exhausted this matter, so to speak, by proving, that 
these two modes of growth distinguish trees whose seeds 
have two cotyledons, and such as have only one ; and 
establishing on this important discovery a fundamental 
division in Botany. 
