626 Transactions of the Royal Society of South Africa. 
this does not happen, the buds, as a result of the fire, appear to be stimulated 
to grow, especially if the burning is done early, before the end of the rainy 
season. When winter comes the young stems are apt to be killed by the 
frosts and winter drought. Aristida, junciformis, on the other hand, has the 
innovation shoots extravaginal, and sometimes it is stoloniferous. The inno- 
vation l3uds are protected by scales. This grass further grows in dense 
tussocks, and soil collects around and between the bases of the culms. 
When the veld grasses are burned — (1) the innovation buds of this species, 
being under the surface of the soil, are not lialjle to be injured by the fire, 
and (2) new growth does not take place so quickly, so that injury from frost 
and drought does not follow. 
Those two species have been selected liecause each is the commonest 
example of its type. The other grasses resemble one or the other. 
The Hemicryptophytes, with their innovation buds, extravaginal or at 
any rate below the level of the surface of the ground, are better adapted to 
withstanding grass fires, and hence, owing to the influence of these fires, are 
tending to oust the Chamaephytes, v>^here the renewal buds are less efficiently 
protected. At the same time it must be remembered that Anthistiria, a 
typical Chamaephyte, is dominant in natural, unchanged veld. It must lie 
assumed that but for grass fires the protection afforded the young buds l)y 
the sheathing leaves and layer of decaying foliage is quite efficient, and the 
fact that new growth can take place quickly in spring must be an advantage 
to the species in the absence of the disturbing factor, fire. 
The above illustrates how a careful study of the autecology of a species 
very often affords an easy solution to questions of economic importance. 
To counteract the " deterioration " in the veld farmers should cease burning 
the grass. 
GEOPHYTES. 
In this class we have the greatest amount of protection during winter of 
all perennial plants, the renewal buds being deeply embedded in the soil. 
The subterranean portions are bulbs, tubers, corms, rhizomes, root buds and 
root tubers, and these contain a storage of food which enables the plant to 
flower early in spring — as a rule, before the work of assimilation is renewed. 
This is an abundant class in South Africa, including all our various bulbous 
monocotyledons. As in the case of the last class, the Greophytes of Natal 
are mostly veld plants, and the type resembles, in some respects, the floor 
vegetation of deciduous woodland in colder, temperate regions. The majority 
of the bulbous veld plants (Greophytes) are able to get their flowering over 
before the grass grows tall enough to shade them, in the same way as 
bulbous woodland plants in deciduous woods flower before the leaf canopy 
