432 Mac far lane— Observations on Pitcher ed 
Attractive marginal glands 1 . These glands, which appear in 
the first foliage-leaf of seedlings, and which are the first indicated 
in developing adult leaves, I regard as the most constant of all. 
Attention was first drawn to them by Dr. J. Gibbons Hunt, of 
Philadelphia 2 , who stated that f in N. Rafflesiana , N . distil- 
latoria , and N. Phyllamphora , and probably in all the species, 
are large cylindrical glands which pour out their secretion 
through distinct excretory ducts. . . A dense tissue of cells 
surrounds and thoroughly embeds these glands in Nepenthes , 
and this peculiarity of position renders excretory ducts neces- 
sary for the secretion to find its way into the pitchers/ In 
1883 Dickson published 3 observations on their structure and 
the relation of the glands in adult and seedling forms. 
For isolation and examination of the marginal glands 
I have found that a very quick and efficient means is by 
macerating the pitchers in boiling potash-solution for fifteen 
to thirty minutes, according to the age and consistency of the 
pitcher, and then, after washing in water, to cut off the collar. 
The inner epidermis of a portion is then gently pulled up till 
near its junction with the marginal glands, and after water has 
been dropped on the slide that carries the object, all the 
mesophyll-tissue is removed by forceps, along with the vascular 
bundles. It is then carefully washed and the inner epidermis 
pulled off, while, if the glands tend to rise or separate with it, 
a sharp-edged scalpel is softly laid across them to keep them 
against the epidermis of the collar now remaining. Prepara- 
tions thus made of N. ampidlaria or N. Hookeri are of extreme 
beauty, and show (Plate XX, Fig. 21) the glands lying in a row, 
each in line with its orifice. In the majority of species their 
size varies strikingly with the relative depth of the conducting 
1 I had hoped that an exhaustive account of these would have been prepared by 
the late Professor Dickson, partly from many preparations that he had gathered 
partly from additions which I was privileged to make in the course of these inquiries, 
but we now mourn his early removal from us. Dr. Archibald Dickson, of 
Hartree, has very kindly placed all the material at my disposal, and from this, 
supplemented by my own slides and notes, I draw the following account. 
2 Proc. Phil. Acad. Nat. Science, 1874. 
3 Card. Chron. (n. s.), Vol. xx, 1883. 
