238 Scientific Intelligence. 
quent experiment. That with the other three commenced on the 
4th of February. The result was that the German trees leafed out 
first. In the case of the Poplar there was a difference of about 23 
days in favor of the individual of the colder locality; in that of 
the Carpinus about 18 days; and in that of the Tulip-tree a nindine 
result was obtained when the comparison was restricted to 
m 
of the same size and degree of donélopmen t. The Catulpa of the 
northern eer) cad aa 20 days in ranges ont the other. 
WwW the same temperature act more powerfully and 
promptly oon the plant of the higher latitude ? sera 
refers it to two oage: attributing, however, most importance to 
the second. First, to a natural selection of the buds which has 
induced the el ce i e buds of a tree are in a con- 
e.:: The 
- prevail, unless indeed they suffer from frost. In this 8 wa si com 
selection and a successive i of the tree to the cltiated? 
And he goes on to show that what effectuates this result is, that 
every peculiarity of a bud i is ordinarily reproduced year after year 
in the succeeding growths. As a case in point he mentions a well 
known Horse-chestnut tree in the environs of Ge eneva, upon whic 
the owner, in the year of 1822 or 1823, detected a single branch 
bearing double flowers ; this still continues, and has all along borne 
double flowers, and shows no tendency to revert to the aig ged 
i tree. G: 
simple-flowered condition of the rest of th rafts 
been taken from it, and it is thought to be abe original of all the 
double-flowered Horse- oo in the wo Although this 
may well illustrate how the ocity as me ~ pass; yet 
DeCandolle doubts whether this ites of ht ranches produces 
ray effect. Because, in the north precocity seems as likely 
o be a disadvantage as an advantage, while at the south it ought 
re heat for vegeta is yet to be proved that an 
individual tree becomes eh better adapted to the climate as it 
s in neral idea tha e does not 
t 
acclimatize. ‘The principal canis of this difference in the vegeta 
tion of northern and southern individuals, in DeCandolle’s opinion, 
is the complete hibernal repose of the former, rendering it some- 
how more susceptible to the heat of spring; ‘tho ough in what way 
is not stated. e would add that if the suggested — 
Pcp bud-selection be not the true one in the case of trees, 
to the general fixity is character in ae er ere sna 
room for variation, yet the e anation = 
api par vai precocious races better a ‘arly to the short 
summer, the only difference being that a more time would be 
required for a tree to fix a race than for an annual. An objection 
