1921] CURRENT LITERATURE 159 
nitrifying agents, are considered responsible for the lack of progressive improve- 
ment of soil conditions and the persistence of xerophytes. The same factors 
account for the relative absence of herbaceous plants. In seeking for the 
origin of this flora, after an examination of the available evidence, Miss Grsps 
concludes that the mountains of New Guinea may be considered as the focus 
of development and distribution of the so-called “antarctic” plants, justifying 
the term Papuan austral-montane for this group, of which, even on the limited 
basis of our present knowledge, nearly one-half of its most characteristic genera 
are now known from New Guinea. The author also contends that the north- 
westerly poleward wind which sweeps persistently over the mountains of New 
Guinea above tree level, in a constant direction and at a constant altitude, 
decreasing in height in its progress southward, is the agency by which this flora 
has been transported. Once established, the elements remain within the 
radius of the lower but equally constant circumpolar wind. 
Collections from these montane associations show 108 species of vascular 
plants, of which 67 are endemic, the most remarkable family being the Conif- 
erae with 7 genera and g species, 3 genera and 8 species being endemic. Other 
large families are the Proteaceae with 8 species, all endemic, the Myrtaceae 
har 5 species, 3 being endemic, the Epacridaceae with 20 species, of which 
, and the Compositae with 19 species, 12 being endemic. Among 
families well represented i in boreal montane regions, but much less conspicuous 
in Tasmania, are the Cyperaceae, Ranunculaceae, Cruciferae, Rosaceae, and 
Ericaceae, each represented by only a single species.—Gro. D. FULLER. 
Aluminum and soil acidity —Mrrasou’ has done a piece of work on the 
relation of aluminum to soil acidity, working on three different acid silt loams 
from southern Illinois. “In the absence of some calcium compounds as a 
source of calcium, aluminum salts were highly toxic to sweet clover when 
_ applied in amounts chemically equivalent to five times the acidity of the soil. 
In the presence “ calcium silicate, aluminum nitrate was more toxic than 
aluminum sulphate... .. uminum mono-hydroxide did not have any 
effect on sweet ns when other plant food elements were added in the soluble 
form. Calcium carbonate in sufficient amount corrected the toxicity of 
aluminum salts, by precipitating aluminum as calcium aluminate, an insoluble 
compound. Acid phosphate applied at the rate of 400 pounds per acre reduced 
the toxicity of aluminum salts by forming aluminum phosphate, an insoluble 
ompound.” Like HARTWELL and PeMBeER, in an article recently reviewed 
in this journal, Mrrasor found that acid phosphate precipitates soluble 
aluminum, but in contrast to these investigators he found that acid phosphate 
decreases the acidity rather than increases it as they had assumed. “The form 
of aluminum immediately concerned in the unproductivity of acid soils in the 
soluble form is the salts. .... n soils sufficiently provided with calcium, 
7 Mrrasot, J. J., Aluminum as a factor in soil fertility. Soil Science 10:153-193- 
20. 
