Botany and Zoology. 281 
during the cool season, he observes how much the species introduced 
from more northern countries contrast with these indigenous species in 
their mode of vegetation. ¥ ’ 
The oak and the beech, for instance, continue to lose their leaves 
during the winter, although the weather is then milder than it is in sev- 
eral parts of Europe during the summer. Thus, at Funchal, the leaves 
of oaks (Quercus pedunculata) planted in some public gardens and 
promenades, began to grow yellow at the end of October, and gradu- 
ally became dried up to the ist of January. Some isolated trees began 
fo shoot by the 10th of January, and were green again on the 6th of 
February ; but all the others remained in a state of repose and were 
hot generally covered with new leaves until the 20th of February. In 
ie ordon’s garden, at an elevation of 1800 feet, they were a month 
later, 
The leaves 
upon the trees, until they began to shoot in the spring, which was about 
the Ist of April. At F unchal, the terminal buds were open by the 8th 
of April, and the lateral a little later. nig 
_ At Glaris, the period of repose of the beech on an average is 194 
ys; in Madeira, where the cold season is like the summer at Glaris, 
Madeira itis only 110 days, or 49 days less than the beech. M. Heer 
s"PPoses that this difference may arise from the beeches of Madeira 
having been introduced from England and the oaks from Portugal, so 
examples in the hothouse culture of tropical plants,—there is a proof 
of that important physiological law, too often forgotten by meteorolo- 
Bisis, that the Same temperature or the same sum of temperatures, com- 
dined with the season, does not always produce the same effect upon or- 
Sanized beings. 
votes wove race of a species and another, and even up to a certain 
Point between one individual and another, but also between one period 
“4 another,—the same heat after the repose of vegetation for instance, 
Rot producing the same effect as in other circumstances. 
eira, the Platanus occidentalis, a native of the United States, 
loses its leaves very slowly from the middle of October, or rather they 
Sradually become yellow and fall afterwards from the action of wind 
