of Lathrea Squamaria, $c. 413 
in this figure) runs along the whole underside of the leaf be- 
neath the course of the dotted line a. b. of Taz. XXIII. 
Fig. 6; and communicates, by means of an oblong narrow 
orifice (Fig 9. c.), with the bottom of each of the perpendicular 
leaf-cells. This appearance may be best detected in a very thin 
longitudinal section of the leaf placed under the microscope ; 
and though the inner curvature of the leaf d. will sometimes 
adhere to the leafstalk e, and close the aperture, the application 
of a needle or bristle will immediately discover it. The cuticle 
of the leaves is destitute of pores on both its surfaces*. When 
highly magnified, it appears to be traversed by an irregular net- 
work of veins, the reticulations a little prominent, and connected 
by a.transparent but strictly imperforate membrane. 
Keeping in view this very curious and singular structure, I 
think its ceconomy cannot be misunderstood; viz. that the 
squamee or scales of the subterranean stem are real leaves, and 
that the prominent glandular papille of their interior cells 
perform the office of true cuticular absorbents. Under ordinary 
circumstances, leaves freely exposed to the action of the air and 
of light, and provided with a porous cuticle, receive carbonic 
acid gas. into the cells of their parenchyma, where the oxygen is 
separated and thrown off, and the carbon assimilated with the 
hydrogen imbibed by the roots. But in the case of the Lathrea, 
where they are destined to perform their functions, not only in 
the dark, but buried in the earth, such an arrangement would 
have been inexpedient ; it is therefore substituted by another, 
" * So is the cuticle of the flower-stem, the individual flower-stalks, the calyx, and 
both surfaces of the bracteas. The copious woolly hair on the flower-stem and calyx, 
when highly magnified, appears jointed like a bamboo cane, and tipped with a globular 
or oval summit; but I cannot ascertain whether they are perforated. The bracteas 
have neither the internal cells nor the bladders of the true leaves; but there are often 
several at the base of the flower-stem, of an intermediate character, being partly succu- 
lent and chambered like the latter, and partly thin and solid like the former. 
admirably 
