May 1, 1895.] 
Supftl'erkefti to the " Tropical Agriculturist.' ' 
775 
The plants which possess this power of abstract- I 
ing nitrogen direct from the air, are those belong- 
ing to the natural order Leguminosae, to which 
order belong peas, beans, vetches, clover, sainfoin, 
lucerne, Sec. On the rootlets of the plants of this 
order" are a large number of small nodules, or 
tubercles. These are the home of micro-organisms 
capable of abstracting free nitrogen from the air, 
and forming nitrogenous compounds. The greater 
portion of this nitrogen ultimately finds its way 
into the plant, and is there made use of. 
The benefit is not confined to the leguminous 
crop alone, but where that crop is ploughed in, or 
even if only the roots are left, the soil becomes so 
enriched by the accumulated nitrogen that greatly 
increased crops result. 
Dr. Wagner, of Darmstadt, conducted experi- 
ments to test the effect of the above. Two equal 
plots were taken, and upon one, white mustard, 
and on the other, vetches were ploughed in, and 
oats sown. Each received an equal dressing of 
artificial manure, but the yield on thnt where 
vetches had been ploughed in was twice that on 
the one where white mustard had been ploughed in. 
Similar experiments were conducted by Heiden, 
rye being taken (1) after lupines, ploughed in, and 
(2) after bare fallow. The relative yields of the 
plots were : plot 1 — 96 of grain and 205 chaff and 
straw ; plot 2 — 56 of grain and 114 chaff and 
sttaw. 
The importance of this fixation of free nitrogen 
cannot be over-estimated, as it provides a large 
quantity of the dearest manurial constituent 
without cost. 2. The food added to the soil by 
green manuring cannot readily be lost by drainage. 
This explains the advantage which light land de- 
rives from it, that class of land not usually being 
retentive of plant food. 3. A large quantity of 
humus is added to the soil, the benefit of which 
has already been noticed. 4. During decomposi 
tion of the vegetable matter, mineral matters are 
rendered available for plant-food, owing to the 
effects of the products of decomposition. 
TROPICAL FODDER GRASS KS. 
The following tropical grasses are selected as 
possessing special merits for fodder purposes. 
Amongst them are plants suitable for almost 
every condition found in tropical countries. The 
list has had the advantage of the revision of Sir 
Joseph Hooker, who is now working out the 
grasses of British India and who has suggested 
some emendations of the commonly accepted 
nomenclature. 
Anthistiria austraiis, R. Brown. — The well- 
known " Kangaroo grass " of Australia, but widely 
distributed throughout Southern Asia and the 
whole of Africa. A perennial upright grass over 
3 feet in height. It enjoys a wide reputation 
and is regarded as the most useful of the 
indigenous grasses of Eastern Australia, stock of 
all dsecriptious being remarkably fond of it. The 
roots are strong, and penetrate the soil to a great 
depth, so the plant remains green during the 
greater part of the summer. In the autumn the 
foliagf (urns brown, when, however, its nutritive 
qualities are said to bo at the highest. If cut ns 
* All iho plants.' Toe C*;saluiuo» must, surely, 
I excepted. " 
soon as the flower stem appears it can be made 
into excellent hay. The most reliable way to 
ptopagate this grass is by division of the roots. 
It perfects very little seed (Turner). 
Anthistiria avenacea, F. v. Mueller. — "Tall oat- 
grass " of New South Wales. A nutritious peren- 
nial pasture grass, often rising to a height of 4 to 5 
feet. It grows generally in tussocks, and prefers 
rich soils, where its roots can penetrate deeply into 
theground. It thus cuu withstand long spells of dry 
weather with impunity. It yields a large amount 
of bottom fodder, and is regarded by Bailey as 
"one of the most productive grasses of Australia.' 1 
It possesses the advantage of seeding freely. 
Turner remarks " it might be profitably cultivated 
for ensilage, especially if it were cut before the 
flower stems become hard and cane-like." 
Astrebla pectiuata, F. v. Mueller. — Widely 
distributed in dry regions inland in North and 
East Australia. Closely allied to " Mitchell 
grass," but usually not so tall- A perennial 
desert grass, resisting drought, and sought with 
avidity by sheep, and veiy fattening to them and 
other pasture animals. Seeding freely Mueller). 
Astrebla triticoides, /''. v. Mueller (Danthonia 
triticoides, Lindl.). — The "Mitchell grass" of 
Australia. A very valuable perennial grass with 
glaucous green leaves. On rich soils it produces 
ft great amount of rich herbage, of which stock 
of all kinds are remarkably fond. Cattle are 
said to fatten on this grass even when it is much 
dried up during periods of drought. It cut when 
about to flower it makes excellent hay. Turner 
" thoroughly recommends it for permanent pas- 
tures." The land should, ho a ever, be well 
drained. 
Cynodon Dactylon, Pers. — A prostrate perennial 
grass with very narrow glaucous gree.i leaves. 
It is widely distributed in all hot countries, and 
extends also into temperate regions. It passes 
under various names, such as "Bahama grass," 
"Bermuda grass," " Indian couch grass, " " Doub," 
and •' Doorva. " It is an important grass for 
coveriug bare, barren land, and for making 
smooth, compact lawns. It resists extreme 
drought, and once established in cultivated land 
it is very difficult to eradicate. It is easily es- 
tablished by planting small portions of the 
rooting stems about 8 inches apart. If done at 
the beginning of the rainy season the ground 
will be completely covered in six weeks. It may 
also be propagated by seeds, which are now 
readily obtained in commerce. It should, how- 
ever, never be planted except in places where it 
is required to remain permanently. When grown 
specially for fodder, in enclosed paddocks, it 
yields three or four crops in the year, and makes 
excellent hay. In very dry seasons in the West 
Indies animals exist almost entirely on the under- 
ground rhizomes of this grass. 
The following note on the use of Bahama grass 
for making lawns in India is taken from Fit- 
miuger's Manual of Gardening > far Bengal and 
Upper India [ C ilcubta, 1871] p. '2(i: — " The grass 
principally usod for lawns in this coun.ry is 
that called Doob-gniss (Ci/nodon Dactylon), a 
plant of trailing habit, not growing high, and 
when in vigorous growth of a soft dark green 
hue. It thrives where scarcely any other kind 
will, und delights in the edges of frequented 
' highways. The spot it 6eems to like especially 
