Osborne^ on the Wheat Plant. 
105 
In this paper I shall confine myself to that period in the 
growth of the plants which gives roots of two or three inches 
in lengthy and an upward growth of the same height ; this 
will be found to have afforded a very wide field of in- 
vestigation. 
In order to observe the growth of the plants I pursued the 
following plan : I procured and constructed small glass tanks, 
which would rest on the stage of the microscope, their back 
and front being of thin glass ; some were constructed suf- 
ficiently shallow to allow of the use of the quarter-inch 
object-glass. 
In addition to these small tanks for observing the actual 
growth of the plant, I have a few glass jars, in which I 
suspend circular plates of perforated zinc over water which I 
treat with various matters ; these plates receive the seed, in 
some instances without any soil, in others with a small 
quantity especially prepared according to the experiment I 
am about to make. From these jars I transplant the seeds, 
as they begin to germinate, into the small stage tanks ; they 
also form my stock of subjects for dissection."^ 
I will now proceed to relate the history of early root- 
growth in a general way; I will then enter into the more in- 
teresting detail of the formation and character of the com- 
ponent parts of a root. 
The first symptom of germination in a seed of wheat con- 
sists in the liberating from its surface a species of filamentous 
network, somewhat similar to the mycelium of many of the 
fungi which infest vegetables; nearly at the same time, the whole 
seed is seen to swell, and become, as to its external covering, 
somewhat transparent. At the germinating point of the seed, 
there now appears a very small wart-like projection of tough 
white matter; this puts forth one cone of the same substance, 
pointing upward, — the future plumule; and several others 
projected in a straight line, soon to curve downwards and be- 
* At the commencement of my investigation into the growth of the 
wheat plant, I had a small nursery of it growing in my garden ; I found, 
however, that though the results scarcely differed in the two cases, the 
plants from my jars being free from soil formed the better subjects for pre- 
parations than those grown in the ground. If a wheat plant is grown in 
very fine sifted soil, in one of the glass tanks, which should be so shallow 
as only to admit a depth equal to that of a root, a half-inch power will 
show a space between the soil and the apparent outline of the root ; a 
quarter-inch will prove this to result from the intervention of a layer of 
transparent plasm external to the main structure. If in a similar tank the 
seed is caused to send roots down into clear water, by pouring in some 
coloured fluid it will be seen that the coloured particles adhere to this 
plasm, and cannot touch the actual parenchyma of the root. 
