336 BOTANICAL GAZETTE [APRIL 
indicates land well adapted to both dry and irrigation farming, the taller 
and thicker the sagebrush the richer the soil. 
Areas next below the sagebrush are occupied by the Kochia (K. vestita) 
association, and this was found to indicate a soil of finer texture, with similar 
moisture conditions, but with only the first foot of soil free from an injurious 
quantity of alkali salts. Dry farming does not succeed on this area because 
of the small amount of soil free from alkali, while the relatively impervious 
nature of the soil prevents the washing out of the alkali by irrigation; hence 
Kochia land scarcely permits crop production. 
Following the Kochia belt comes the shad scale (Atriplex confertifolia) asso- 
ciation, with soil moisture and alkali conditions similar to the preceding, but 
with a soil containing much gravel. Here dry farming does not succeed, but 
with irrigation the alkali would be more readily washed out and hence the crop 
probabilities are better. 
The study continues with the associations of the lower, more alkaline areas, 
indicating as before the agricultural possibilities of the land. In addition to 
the value of the various associations as crop indicators, their composition 
is detailed, the successions noted, and the root characters of the principal 
species studied. The report is an excellent example of applied ecology.— 
G. D. Futter. 
The ecology of Calluna.—The common European heather, Calluna wil- 
garis, has been regarded as a typical calciphobe by ConTEJEAN and other pat- 
tisans of the chemical as opposed to the physical theory of plant distribution. 
Furthermore, the heather is regarded as partial to acid soils, which also are 
deficient in certain mineral constituents, and hence are betokened sterile. 
Calluna occurs in various places on the chalk downs of southern England, being 
accompanied by several other species that are alien to the ordinary flora of the 
chalk; usually the heather patches are sharply delimited from the surroun 
chalk associations. Miss RayNER™ has been making some detailed investiga 
tions of Calluna on the downs, and although much remains to be explained, 
a large contribution has been made to the ecology of the species. On the downs 
the heather grows in neutral soil, rich in most ordinary mineral constituents, 
but poor in lime; the roots, however, often penetrate down into soil areas 
are rich in lime. The proportion of magnesia is relatively high. Cultures 
were made in soil from the heather areas and in ordinary chalk soil contaming 
over 40 per cent of calcium carbonate. In the latter soil there were noted 
certain abnormalities, such as reduced capacity for germination and arrest 
* RayNeR, Miss M. C., The ecology of Calluna vulgaris. New Fiske re 
‘59-77. pl. 1. figs. 2. 1913; see also preliminary paper, ibid. 10:227-249- figs. 2. 
