606 
NATURE 
[Oct. 22, 1885 
storing fodder as an auxiliary to the farmer, but because 
it evokes discussions which tend to the diffusion of the 
teachings of biologic science, and to widen the search 
after natural knowledge. The harvesting of ripe crops 
has become stereotyped by custom reaching back into 
the dim past ; the practice of ensilage, on the other hand, 
involves a view of plant life which is not only foreign to 
our agricultural traditions, but is based upon less obvious 
teachings of nature, and it therefore demands a more 
intelligent cooperation of human industry. Notwith- 
standing these features, which make it a serious innova- 
tion, the unprejudiced acceptance of the system and the 
impartial spirit in which it is being practically investi- 
gated, testify to the growth of scientific culture amongst 
our agriculturists and to the general interest taken by 
them in the more recondite discussions of natural science 
which cannot fail to be widened by the study of the pro- 
found problems presented by the subject of ensilage. In 
contributing to the study of these we shall do so rather as 
observer than investigator, and as the text of our dis- 
cussion we shall take Mr. Fry’s excellent little work on 
“ Sweet Ensilage.” Whatever the fate of the theory of 
the silo expounded by the author—and it is certainly a 
bold excursion into the ¢erra zmcognita—he furnishes us 
with a good and clearly expressed working hypothesis 
for the regulation of the system to the production of 
“sweet ” ensilage, to which his efforts as an agriculturist 
have converged, he has sought a warrant in the teachings 
of vegetable physiology, and the theoretical account of 
the silo which has resulted may be stated in broad out- 
lines as follows :—The crop to be ensiled is cut in the full 
vigour of the growth of the plant; the tissues of the plant 
do not die, but continue to exercise their organic functions 
for some time after being deposited in the silo. The rise 
of temperature which ensues in the silo is due to what the 
author terms “ intercellular oxidation,” or, from what we 
gather from the context, to the oxygen respiration of the 
cells. 
In consequence of this increased temperature and its 
maintenance for a sufficient time, the cells of the plant 
are deprived of organic activity. The life of the plant 
under the restricting conditions of ensilation, induces an 
“intercellular fermentation,” which manifests itself in one 
direction by the trans-generation of sugar into alcohol, 
the sugar being derived from the starch of the plant by 
hydrolysis. In regard to this function the author goes so 
far as to say: “ When these transgenerations in the silo 
have been performed, the functions of the vegetable cells 
are at an end and they become inert and moribund.” The 
formation of acztic acid in the silo, as also of lactic and 
other acids, are referred to ferment actions. The para- 
sitic organisms present in the original mass are reduced 
to inertness by exposure to the elevated temperature 
produced in the silo, provided this is sufficiently high ; 
nor can they resume their functions when the temperature 
falls to within the limits favourable to life. The ensiled 
matter, therefore, having attained and maintained for a 
sufficient time this suicidal temperature, is thenceforward 
without the pale of organic change. If, however, from 
any cause—the author gives prominence to two: viz. 
insufficient robustness of the cells and too large a propor- 
tion of water, which conditions, e.g., are correlated in an 
immature growth—this critical temperature (at or about 
50° C.) should not be reached, then the contents of the 
silo will, on cooling, become the prey of the bacterial life 
which has survived, and is ready to avail itself of favour- 
able conditions for active development. The latter con- 
ditions determine the production of “sour” silage, the 
former of “sweet.” ‘In the chapter on the chemical com- 
position of silage, in which analyses of various products 
are given, special attention is directed to the relatively 
high proportion of albuminoid to amide nitrogen in those 
which may be ranged in the latter class, as indicating 
their superior feeding value. 
As a necessary preliminary to our discussion of the 
phenomena of the silo, in which we shall follow the lines 
thus laid down by Mr. Fry, we will review a few of the 
more prominent features of the chemistry of plant life, 
which no writer on this subject can afford to leave out of 
consideration. 
That they have been considered, to some extent, in the 
account of the silo above detailed, is evidently due to Mr. 
Fry’s position as an agriculturist writing for agriculturists. 
The practical purpose of his investigation and description 
of ensilage was only attainable by aiming at @ probable 
truth to the exclusion of the whole truth. Our attempt 
will be to do justice to such an aim and its results, at the 
same time to aid in maintaining the scientific perspective 
of the question. 
Many fruitless definitions of the supposed ultimate 
distinctions between a plant and an animal have from 
time to time been advanced ; and while the controversies 
to which they have given rise have but little interest to 
those who take the broader view of classification, still 
there are certain very marked distinctions between the 
vegetable and animal worlds, considered each as a whole, 
which are independent of all views as to their abstract 
import and of all attempts to reduce them to a typical 
expression. First, in regard to synthetical activity and 
the power of appropriating carbon and _nitrogen—the 
characteristic elements of living matter—the position of 
the vegetable world is anterior to that of the animal ; or, 
to attempt a definition, the synthetical work of plants is 
ultimate, that of animals proximate. Secondly, nitro- 
genous or proteid substances are not essential constitu- 
ents of the more prominent structures, 7.e. the fibrous 
skeleton of a living plant, whereas the tissues of the 
animal are largely composed of such compounds. With 
regard to the functions of the protoplasm of the vegetable 
as compared with those of the animal organism, we may 
quote Michael Foster (“ Physiology,” 2nd ed., 343) :— 
“Tt is not unreasonable to suppose that the animal is as 
constructive as the vegetable protoplasm, the difference 
between the two being that the former, unlike the latter, 
is as destructive as it is constructive.” Thirdly, the 
synthetic activity of plants does not cease with the 
cessation of life, but persists in some measure in 
the substances which it has built up. We use the 
term “synthetic” here in a wider sense. The vast 
aggregations of the vegetable life of past ages with which 
we are so familiar in so many forms sufficiently illustrate 
our meaning ; and the study of the everyday work of the 
redistributing agencies of Nature upon moribund veget- 
able matter, will prove the same refractory relationship— 
the possession of a power of resisting change under their 
influence not possessed by animal matter. Resolution 
takes place to a certain extent, in degree depending upon 
the circumstances of its deposition, and the surrounding 
physical conditions, but there is always to be observed 
the tendency to accumulate the characteristic element 
carbon, at the expense of the oxygen and hydrogen ; we 
have every reason to regard the processes by which this 
result is attained as a self-contained re-arrangement of 
the matter and energy, localised in and by the plant 
during its life,and as the result, therefore, of the same 
activity. The life-history of a perennial plant also points 
to a high endowment of the molecules which are built up 
into its permanent parts; for these are not, as in the 
animal, subject to perpetual removal and renewal, but 
fixed and permanently localised. At the same time they 
run a long course of adaptation to the ever-changing 
condition of the structure which they compose, for 
which the necessary energy must be either concurrently 
or aboriginally supplied, or, as is probably true, both 
conditions of supply obtain. The study of the che- 
mistry of liquification, and of the fate of moribund 
vegetable matter, therefore proves the possession of a 
high degree of intrinsic energy by plant substances, 
