40 
ORGANOGRAPHY. 
BOOK I* 
the light of glands. Nees von Esenbeck and Link deny the 
existence of any perforation in the stomates, and consider 
that the supposed opening is a space more pellucid than the 
surrounding tissue, and that what seems a closed up slit is the 
thickened border of the space. Link further adds, that the 
obscuration of the centre of the stomates is caused by a pecu- 
liar secretion of matter, as is plainly visible in Baryosma 
serratum. (Elementa, p. 225.) To the views of these writers 
is to be added the testimony of Brown (Suppl. prim. Prodr. 
p. L), who describes the stomates as glands which are really 
almost always imperforate, with a disk formed by a membrane 
of greater or less opaqueness, and even occasionally coloured ; 
at the same time he speaks of the disk being, perhaps^ some- 
times perforated. 
In the midst of such conflicting testimony, an observer 
necessarily finds much difficulty in fixing his opinion. 
In no plants are stomates larger than in some Monocotyle- 
dons ; they are, therefore, the best subjects for examination 
for general purposes. In Crinum amabile they evidently con- 
sist of two kidney-shaped bodies filled with green matter^ 
lying upon an area of the cuticle smaller than those that sur- 
round it, and having their incurved sides next each other. 
In some, at the part where the kidney-shaped bodies come in 
contact, there is an elevated ridge, dark, as if filled with air, 
and having its principal diameter distinctly divided by a line. 
(Plate IIL fig. IL) In this state the stomate is at rest : but 
in others the kidney-shaped bodies are much more curved ; 
their sides are more separated from each other ; and there is 
no elevated ridge : at their former line of contact there is an 
opening so distinct and wide as to be equal to half the dia- 
meter of one of the kidney-shaped bodies ; this, I presume, is 
the stomate open. That what is described to be an opening, 
is really so, seems to be demonstrated by the following tests : 
— L It is more transparent than any part of the most trans- 
parent portion of the cuticle ; 2. It admits transmitted light 
without interruption ; as is seen by gradually augmenting the 
magnifying power by which it is viewed, when the opening 
continues transparent, notwithstanding the great loss of light 
that attends the use of very high powers in compound mi- 
