THE LIFE OF A SEED. 
401 
m the other but little. The coats of the ovule then become the 
investment of the seed, after having undergone no slight amount 
of change of appearance. 
The nucleus, our starting point, either becomes obliterated as 
the embryo plant grows, in which case the latter, when fully 
developed, occupies the whole of the seed, and is immediately 
covered by the seed-coats, or it remains behind in the shape of 
the “perisperm” or ‘‘albumen,” and which, like its namesake in 
this particular if not in others, serves as a storehouse whence the 
embryo plant derives its nourishment during the course of its 
development. If there is no albumen, then the little plant 
draws upon itself, and from its large cotyledons derives the 
dextrin and other soluble matters which it requires during ger- 
mination. 
To this last process we must now devote a few words. It 
is one of those daily phenomena which we look on as matters 
of course, never thinking that it is as much a subject for marvel 
and for gratitude as any miracle, never realising that, but for 
the life within the tiny seeds, this earth, with all its beauty and 
all its bounteous stores of nourishment, would be a dreary, 
desolate, lifeless waste. The main facts relating to germination 
are so familiar that it is needless to dwell upon them, but some 
of the changes which occur during the process are not so fami- 
liar, and may be briefly alluded to. To state the matter in a 
few words, the case stands thus : given a perfectly constructed 
seed and a sufficient degree of heat, moisture, and oxygen, and 
germination will ensue whether the new plant begin life on a 
wet flannel, such as sailors are- said to use in raising a salad on 
board ship, in the maltster’s heap, or in the carefully tended 
seed-pan of the florist. 
The physical alterations, or those that are visible to the eye, 
are of less interest than the chemical changes that ensue during 
the process. While the former consist merely in the swelling 
of the seed as it imbibes water, the protrusion first of the root 
of the embryo through the foramen, and subsequently of the 
remaining portions of the young plant, and the gradual disinte- 
gration of the seed as the seedling increases in size, the latter 
are far more complicated, and, indeed, can hardly be said to be 
thoroughly understood even by chemists themselves. Some of 
the main facts, such as the emission of carbonic acid gas, the 
conversion of the starchy matters into dextrin, gum, and sugar, 
the replacement of the insoluble fatty materials by others of a 
more soluble nature, and therefore more suitable to the require- 
ments of the growing embryo, have long been known, as also 
has the evolution of heat, which occurs as a consequence of these 
changes. 
With reference to the solution of the starch grains during 
