386 Groom. — On the leaves of Lathraea Squamaria 
shoots. Further, this plant is very frequently found in soil 
which is very moist, or thoroughly wet, during the active 
vegetative season. It consists of a branched rhizome bearing 
many lateral roots. The roots spring from the sides of the 
rhizome and bear many lateral haustoria. The scales on the 
rhizome are arranged in a decussate manner and closely 
packed together. Each scale is pocket-like in form, with the 
mouth of the branched pocket-cavity opening on the lower 
face of the leaf. The epidermis lining the cavity represents 
the lower face of the leaf ; it is devoid of stomata, but 
possesses hairs of two sorts: — (i) shortly-stalked capitate 
hairs ; (2) peculiar dome-shaped hairs, often described as 
sessile glands. Both forms of hairs are glandular in ap- 
pearance. 
Proof of the excretion of water. A healthy flowering 
specimen of the plant was dug up from damp soil. Water 
was forced into the open ends of cut shoots by means of 
columns of mercury varying from 12-24 inches. Subsequent 
examination, after a lapse of some hours, showed that 
excretion had been so vigorous as to cause an outflow of 
water from the pockets of the younger leaves. I could not 
prove that there had been any excretion of water from the 
oldest leaves: there was not sufficient to cause an outflow 
from their pockets which contained both air and liquid. 
Larger parts of the plant kept, with rhizomes and roots 
dipping into water, and in a saturated atmosphere, did not 
excrete water sufficiently rapidly to cause any overflow from 
the pockets. 
Owing to the peculiar form of these leaves, it is impossible 
to see directly which portions of the epidermis lining the 
pockets are responsible for the excretion of water : it was 
only possible to show that the water came from the cavities, 
and not from the epidermis of the upper face. Experiments 
of forcing coloured solutions into the leaves gave no satis- 
factory results. Fortunately a number of parasitic Scrophu- 
lariaceae (3) possess hairs like those of Lathraea ; I therefore 
examined several of these plants. 
