.Tan. 1, 1904.] 
THE TROPICAL AGRICULTURLST. 
449 
stamens of the flowers of Smooth Cayenne is 
applied to the moist and adherent stigma of the 
Ripley, and the flower-head is again wrapped np, 
and so protected against any other mode of polli- 
nation, which would of course impair and render 
nocertain the result. 
That this delicate operation has been skilfully 
performed at Hope is shown by the abundance of 
the seed obtained and the large number of seedling- 
plants procured. I estiroated that there are this 
year between 1,5C0 and 2,000 seedling-plants thus 
cross-fertilised and known as Cayenne x Bipley, 
growing in the nurseries at Hope, so that there 
is surely a hopeful chance of more than one 
superior variety being evolved. 
CAKE OF THE YOUNG SEEDLINGS. 
These tiny favorites are growing under glass in 
the orchid-houses, occupying a part of each house. 
The heat of the solar rays is modified by applying 
a coat of whitewash to the glass roof, and ample 
ventilation is secured by open doors and windows. 
On the bench beneath the glass roof water-tight 
boxes containing coarse and well moistened with 
water were placed, and the seedlings after being 
germinated in shallow pans were pricked out into 
small earthenware pots tilled with suitable compost. 
The plants are not watered. It is the sand which 
receives a regular watering, and the porous pots 
absorb by physical attraction sufficient moisture for 
the nutrition of the young plants. True to their 
hybrid origin, these little plants were widely dif- 
ferent in their characters. No two, indeed, could be 
compared with each other as being alike. To my 
idea many of them showed signs of a predominat- 
ing Ripleian feature in the incipient spiny foliage. 
This final test is the fruiting, which will be 
waited with interest. — Journal of tli e Jamaica Agri- 
cullural Society. 
SOIL INOCULATION POR LEGUMINOUS 
PL.\NTS. 
TO INCREASE THE SUPPLY OF NITROGEN. 
Of the three elements, nitrogen, phosphoric ac-id 
and potash, going to make up the value of fertilizers, 
nitrogen is by far the most expensive, costing about 
15 cents per pound, while phosphoric acid and potash 
cost only about five. While nitrogen is abundant in 
nature, forming four-fifths of the atmosphere, it is 
only under certain conditions that this uncombined 
nitrogen becomes available for plant growth. 
It has long been known that leguminous plants, t 
such as cow peas, velvet beans, alfalfa, the vetches, s 
the clovers, etc., are usually rich in nitrogen andt 
increase the nitrogen of the soils on which they grow. 
This was not fully explained until science brought 
out the fact that this family of plants is able to 
obtain the nitrogen from the air. 
THE BACTERIA NODULES. 
It has been found tha,t the power of securing free 
nitrogen exists only when small nodules or tubercles, 
containing bacteria, are found on the roots. It is 
now generally believed that these bacteria by some 
mysterious process, draw the nitrogen from the air, 
which is ever present between the soil particles, 
and converts it into forms which can be utilized 
by the plants on which tubercles grow. These tu- 
bercles may readily be seen by examining the roots 
of any leguminous plant grown under favourable con- 
ditions, i. e., soils deficient in nitrogen, which con- 
tains the germs for the development of the tubercles 
on the particuhir legume. If the soils are nbundantly 
supplied with nitrogen there is little need for the 
bacteria, an! the nodules which they produce are 
not BO likely to occur on the roots. On the other 
hand in soils poor in nitrogen (most soils are) the 
bacteria, if preset in sufficient quantity, attach them 
selves to the roots in largo numbers and 
STIMULATE THE PLANT, 
upon which they grow, to produce tuberciesj and 
thus provide the necessary nutritive substance for 
the growth of the bacteria, while in return the plant 
receives the nitrogen which the bacteria alone can 
take from the air, rendering it available for the 
plant. 
It has often been noted that when a leguminona 
plant was grown for the first time on a soil it fre- 
quently produced no tubercles and failed to thrive ; 
this is true in many instances even though some 
other legume has been successfully grown on the 
same soil the previous season. This led to the con- 
clusion that, at least, each genus of legumes has its 
own kind of bacteria. No legume is likely to thrive 
unless the bacteria necessary for that particular 
legume is present in the soil. Bacteria are left in 
the soil in great numbers by the decay of the tubercles 
left from a previous successful growth of a given 
legume. 
The introduction of bacteria into the soil where 
rarely grown legume seed are to be planted, is com- 
monly known as inoculation, that 
IT PAYS TO INOCULATE SOILS, 
for at least some legumes is evidenced by the fol- 
lowing figures : Duggar, (Ala.) Experiment Station 
reports that inoculation increased the yield of Hairy 
vetch from 2??2 pounds, cured hay per acre on unin- 
cculated plot, to 2,540 pounds on inoculated plot. 
Inoculation increased the yield of crimson clover 
from 761 pounds, cured hay per acre to 4,057 pounds. 
Similar results according to Prof. H. Benton in the 
Florida Agriculturist have been obtained with clover, 
vetch and alfalfa in Louisiana, Canebrake Station, 
Alabama, and other stations. 
METHODS OF INOCULATION. 
There are at least three methods by which 
soils may be inoculated. One method is to 
find a field on which a crop of the plant to be 
grown has made a satisfactory growth and 
where the tubercles have developed in abundance, 
thus being sure that the bacteria are present in 
abundance. Haul the soil from the inoculated field, 
using that from two to three inches deep, as the 
germs in first inch may have been killed by sunshine, 
and that deeper than three inches may not con- 
tain the bacteria in sufficient numbers. Scatter 
about one ton per acre over field to be inoculated. 
This inoculated soil should be quickly harrowed in 
to prevent the sunshine killing the germs. If the 
seeds are to be sown in drills it is better to put 
the inoculating soil in the drill with the seed. 
A second method is to obtain some soil from an 
inoculated field, about half bushel of soil to each 
bushel of seed to be planted, place it in a vessel and 
pour water over it ; stir vigorously, allow the larger 
particles of soil to settle, use this murky water to 
thoroughly wet the seed before sowing. The seed 
may be dried again if kept out of the sunshine. The 
germs which should be in the murky water stick to 
the seed and inoculate the soil on which they are 
sown. This is at present the most economical method 
of inoculating a field, 
NITROGEN AS A FERTILIZER, 
The third method is to buy a material known aa 
nitrogen. This is simply a gelatinous substance full 
of the germs one wishes to use. Pare culturea of 
nitrogen may be obtained for peas, beans, the vetches, 
lupines, the clovers, alfalfa, mellilotaus and flat pea. 
There are two methods of using nitrogen as an 
inoculating material. One is by bringing the nitro- 
gen into solution by using pure water, and sprinkling 
this solution over the seed to be planted. The other 
method is by mixing the nitrogen with a small 
portion of the soil, then scatter this soil over a pre- 
pared field and harrow in immediately. The cost of 
inoculatmg an acre with nitrogen is about §2'50 per 
acre. One bottle of the prepared nitrogen is sofBcient 
to inoculate one-eight of an acre. Owing to the 
fact that nitrogen has to be transported across the 
