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NOTES ON THE OCCURRENCE OF ALPINE TYPES IN 
THE VEGETATION OF THE HIGHER PHAKS OF THE 
SOUTH-WEHSTERN REGION OF THE CAPE. 
By R. Maruotu, Ph.D., M.A. 
(Read April 27, 1899.) 
(Plates XXII., XXIII., XXIV.) 
In ascending the higher mountains of a country one notices a 
more or less gradual change in the vegetation, according to the 
different altitudes. Although the mountaimeer may have no know- 
ledge of botany, he recognises the great difference in the general 
habit of growth of the plants of the higher and lower regions. 
Long-continued observation and cultivation of plants on high 
mountains and in the plains have shown that the characteristics 
of Alpine vegetation are principally due to the Alpine climate, and 
not to the peculiarities of the soil. As far as the climate is con- 
cerned, it is often thought that the principal factor in shaping the 
plants is the cold and frost, owing to which the plants are not able 
to reach greater dimensions. It is thought that the vegetation of 
high mountains, particularly of those above the snow line, is subject 
to similar conditions as that of the Arctic regions, and that conse- 
quently these two vegetations should be more or less identical. 
But that is not so, and although in some respects such similarity 
exists, we find a great difference in others. Common to both climates 
are the low temperature and the excess of light, but in both respects 
there is a great difference of actual conditions. While the Arctic 
plants, even in summer, are exposed to an only moderate heat, 
those of the Alpine regions have to resist extreme heat and cold 
in rapid succession, owing to the powerful insolation and radiation 
in the rarefied air of the higher elevations. 
More pronounced even is the difference in the amount of illumina- 
tion which they receive, for while in the former case the light is weak 
but continuous, it acts only periodically but with great intensity in 
the latter, and while the risk due to the want of water is caused in 
the Alpine regions by the occasional extreme dryness of the air, this 
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