THE STEM OF A SPECIES OF CUCURBIT. 195 
cut from the same plant, which contained this hair-cavity. In 
one piece I was able to trace its origin as above described. It 
extended for several inches along thestem, but I was unable to 
follow it to the end. 
It was difficult, too, to say definitely to what species of 
Cucurbit the little piece of stem belonged. However, I have 
this year made sections of, and examined carefully, all the species 
of Cucurbits which are grown in the gardens from which the 
specimens might have been derived. 
These include—Cucurbita maxima and var. turbaniformis, C. 
Pepo and its varieties aurantia, verrucosa alba, and mammeata, 
Lagenaria Sipho, L. congourda, L. clavata, L. pyrotheca, L. 
vulgaris, Cucumis Sacleuxit, and Benincasa cerifera. 
With the exception of the last named, Benincasa cerifera, the 
stems of all the species differ slightly from that in which I found 
the hair-cavity, so that now I am sure that it was from Benincasa 
that the pieces which I examined were cut. 
The specimens of Benzncasa cerifera now growing in the 
houses are not yet full grown. 
However, in the young growing plants near the nodes I notice 
that there are appearances of meristematic tissue similar to that 
above described. I am unable to say whether the hair-cavity 
will develop later. 
The Nature of the Cavity and Hairs. 
De Bary* describes various kinds of Internal Hairs. He 
divides them into two categories, glandular and non-glandular. 
The only forms of the first category, he says, are those glandular 
hairs first noticed by Mettenius, and described later by Schacht, 
in the air-cavities of the rhizome and base of the petiole of 
Aspidium Felix-mas. These are unicellular capitate hairs, and 
secrete “a firm greenish brilliant thick layer of resin.” 
Intercellular hairs of the second category occur in P2lularia, 
Nympheacee, Arotdee, Rhizophora, and Limnanthemum. 
In Pilularia they are rolled up like watch springs; in 
Nympheacee they are stellate hairs, and in the others they are 
either stellate or H formed, and according to De Bary they are 
* Comparative Anatomy of Phanerogams and Ferns, Sect. 53. 
