93* 
THE TROPICAL AGRICULTURIST. 
[May 1, 1882. 
ravine unavailable for the growth of trees requiring 
sunlight for the development of their flowers or fruits. 
Many of the Coffe trees there are in consequence 
non-productive. This fine tree has lately attracted 
some attention from having ascribed to it in South 
America the peculiar capacity of exuding a moisture 
in the form of fine rain. It thus became invested 
with the name of Rain-tree. The trees in .this quarter 
however have never exhibited any such peculiarity. 
Its character as a pasture tree is in high esteem 
everywhere, bearing as it does large quantities of 
highly nutritious beans which are an excellent fodder 
for cattle, and ripening at a time, February and March, 
when grass is most scarce— except that, by their 
astringency apparently, they certainly have the effect 
of diminishing the yield of milk in cows. There 
would appear to be an erroneous notion abroad as 
the character of its wood, conclusions having been 
arrived at from the study of the character of wood 
found in young trees — say below 20 years, and the 
wood had been pronounced sappy and worthless. 
Such, however, is not the case with wood of matured 
trees. In such, the wood is almost exactly that of 
old chestnut, and that too with a very small amount 
of sap-wood. Moreover the wood is specially valuable 
as check blocks for the Bail way brakes, and indeed 
for any purpose in which non-liability to wrap even 
in our sun, great strength, combined with toughness, 
and durability above ground are essential. The saman 
trees raised from seed and planted in the Queen's 
Park in 1866—14 years ago, now measure at 5 feet 
from ground nearly 8 feet circumference, and with 
a spread from opposite sides of 96 feet. This about 
equals the size attained by Elms in Europe in 50 or 
60 years. The young trees planted on the western 
side of Belmont pasture 18 months ago, have done 
well, and now make some effect : Inga saman is 20 
feet high.— Report Trinidad Gardens. 
CHANGES ACCOMPANYING THE RIPENING 
OF CERTAIN PLANTS* 
BY P. P. DB'HE'BAIN AND BRE'AL. 
Deherain explains the loss in weight of dry matter 
which occurs during the maturation of tbe seed in 
the cereals and other plants. The formation of the 
seed involves the transport of carbohydrates and 
nitrogeneous bodies from one part of the plant, to 
be afterwards stored up in another part. In the 
case of the carbohydrates, this transport does not 
necessitate any loss in weight, since they exist in 
the form of reserve materials (starch, etc.), which 
take no active part in the phenomena of growth. 
But in the transport of nitrogeneous bodies a certain 
quantity of protoplasm has to disappear from the 
living cells in the form of asparagine, to reappear in 
the seed as legumin, glutin, etc. Assimilation then 
ceases in the cells thus deprived of protoplasm, but 
oxidation still goes on, and thus a loss of weight is 
produced. The authors distinguish three cases. In 
those plants which flower rapidly and bear simul- 
tanpously, a large number of flowers in proportion to 
the size of the plant (Sinapis nigra, Colinsia bicolor), 
there is always a loss in weight of dry matter ; 
assimilation suddenly ceases throughout a large por- 
tion of the plant, but oxidation still goes on. In 
plants which do not produce many flowers at once, 
nor in too great proportion to the leaves, ripening is 
accompanied with only a temporary loss of weight; 
a sufficient number of chlorophyll granules remain 
intact to carry on the work of assimilation, which 
proceeds with renewed vigour after the seeds have 
* Ann. Agronomiqv, vi. , 398 — 400. Reprinted from 
the Journal of the Chemical Society, January 1882. 
ripened (EschscJwltzia Californica, Delphinium ajacisj. 
When the flowers are very few and the leaves 
numerous (Papavera somniferum, HesperU maritima, 
Silene pendula), the dry matter increases in weight 
during the ripening of seed. — Pharmaceutical Journal 
SOME EFFECTS OF HEAT AND LIGHT 
ON VEGETATION. 
A curious modification of the normal structure of 
plant stems has been observed by M. Prillieux on 
making the temperature of the ground about the plant 
higher than that of tbe air above. Beans and pump- 
kins gave the best results. The seeds were placed in 
earth in a large dish, in which was inserted part of 
a brass rod bent at a right angle and having a gas 
flame applied to its horizontal end. The chamber was 
moist and coid. The seed germinated well; but on 
coming above ground ths plants acquired a peculiar 
shape, they grew but little in length and became 
unsusually thick, the latter growth involving much 
tension in the surface layers, so that deep rifts before 
long appeared (mostly transverse) and made further 
growth impossible M. Prillieux found tbe enlargement 
traceable mainly to an increase, not of tbe number, 
but of the volume of cells in the interior (cells of 
the cortical tissue and the pith). The excessive growth 
of these cells occurred not only in the cell wall, but 
in the nucleus, which was often multiplied. The excess 
of temperature of the ground over the air was about 
10 deg. Again, the view adopted by the older botan- 
ists that light is either without effect on germination, 
or as an adverse effect fails to harmonize with some 
results lately arrived at by Herr Stealer, in the case 
of many seeds of agricultural importance, such as 
varieties of meadow grass ( poa J, the germination of 
which he finds to be favoured considerably more by 
light than by heat. Thus, with two groups of 400 
seeds each of Poa nemoralis, in one experiment, there 
germinated in light 62 per cent, and in darkness 3 
per cent. Similarly with Poa pratemis in light 59 per 
cent; in darkness 7 per cent, and so on. Sunlight 
being a very variable force difficult of determination, 
experiments were further made with gaslight, and 
with the same result — that light favours the germin- 
ation of certain seeds, especially grasses, and that 
these germinate either not at all, or very scantily, 
in darkness. The fact was verified by Herr Stebler 
in quite a series of seeds, Festuca, Cynosurus Alopecurus, 
&c. In the case of seeds that germinate quickly and 
easily, such as clover, beane, or peas, be thinks light 
is probably not advantageous. — Planters' Gazette. 
MATE. 
Mr. L. Couty, after a special visit to South America, 
contributes to the Revue Scientifique an article giving 
the results of his examination of the food question on 
that continent, especially with respect to nutrious 
beverage known as mate, which he believes is destined 
to replace coffee and alcohol to a gnat extent. The 
leaves are derived from the Ilex Paraguayensis, which 
grows to a height of from three to six metres, and covers 
acres of ground throught Paraguay, Bio Grande, Parana, 
and the province of St. Catherine. This represents 
an extent of country larger than France and Germany 
combined. The leaves, which are thick and oblong in 
shape are only picked every three or four years. They 
are dried by artificial means in tbe woods by the 
peasants themselves, who send them in a rough state 
to the factories. Here they undergo a separating 
process by means of sieves, and are afterward packed 
ready for sale. In preparing the beverage the leaf is 
boiled for one or two minutes, the liquid furnished, 
being less limpid than tea, and not so dark as coffee. 
The aroma is les* pronounced thau that of good tea, 
