628 ON THE EMBRYO OF TROPGOLUM MAJUS. 
part of the ovule has become much bent and elongated; so 
that the micropyle, a, is inconspicuous. The substance of the 
nucleus is nearly obliterated, and the upper part of the cavity 
is much corrugated. At the point where the embryo, e, is 
connected with the root-like process at J, the latter is firm 
and somewhat tuberculated. It thence becomes attenuated 
into a cellular thread, whose course may be traced to 4, 
where, from a tumid knob, two branches are sent off, the 
one (f) round the seed on the external face, within the car- 
pellary integument; the other, (g), passes down a narrow 
channel in the substance of the carpel, to A, the lowest point 
of junction with the receptacle, where there is a small pore ; 
i, is a portion of the style. The radicle of the embryo is 
covered with a thin membrane, which arises from the base, l. 
In an early stage, this membrane probably covers the whole 
of the embryo, properly so called, and may perhaps be 
regarded as the true vesicule primordiale of Mirbel. In one 
example, an embryo was seen fixed and detained in the 
position marked m, abortive, but in a state of considerable ` 
development, while the cavity below, equally large with that 
here represented, was filled only with liquid. 
Fic. 11. The process from the embryo, at its junction 
with the radicle, more highly magnified than at /, in the last 
figure. The embryo has been detached, in order to show the 
membrane, p, which surrounds the radicle. 
In conclusion, let me, with Mirbel and Spach, strongly 
urge the adoption of a scrupulous and well-regulated method 
of conducting these and similar investigations. I do not he- 
sitate to declare, that more will be learned by a good mani- 
pulator, under an ordinary lens, than by the possessor of the 
best microscope, who is unskilled or careless in the employ- 
ment of dissecting instruments. It is while the parts are in 
a state of mobility ; not after the dissections are made, and 
in a state of rest, that we acquire just ideas of structure and of 
form. "The fingers, the organ of touch, are essential to the 
attainment of correct views of things too small for the naked 
eye; and never should the visual organ alone be trusted in 
