Francis E. Lloyd —64— Carnivorous Plants 



apart, there being about 10-12 rows of cells to each sulcus (N. am- 

 pullaria) {8—17). Whether the very large ridges that occur in TV. 

 villosa are secondary, or of the third order I cannot say, as I have 

 had no opportunity of examining the plant. The pubhshed drawing of 

 Hooker (1859) suggests the former. 



The epidermis seen in a transverse section is complicated and re- 

 quires elucidation. One may see a row of cells equal in size or larger 

 cells separated by a pair of smaller ones (8 — 18). The latter are the 

 backward extensions of two cells which straddle the large one between 

 them. Two small cells, one on each side of the larger one, are therefore 

 really the backward extensions of a single cell. Atop each large cell 

 there is a central projection of various dimensions. This is the over- 

 lapping point of another neighbor cell, and appears as a solid mass of 

 cellulose, or with a lumen, according to the position of the section. 

 It is evident that the ridge is composed of the continuity of overlaps 

 (Heide 1910). N. Lowii presents a different appearance {8 — 12). The 

 overlapping spur is not lengthened so that no sharp ridge can be seen in 

 transverse sections. Only where the secondary ridges occur do the cells 

 give indication of striae; these not as well marked as in N. ampullaria. 

 With regard to these details Macfarlane's account (1908) is inadequate. 



The ridges of the second order of magnitude, those readily seen 

 by the naked eye, end at the inner edge of the peristome in more or less 

 prominent teeth. When these are definite and prominent there can 

 be seen between them re-entrant bays marking the marginal pits, at 

 the bottom of which lie the flask-shaped glands first observed by Hunt 

 (1874), further studied by Dickson (1883) and called by him "mar- 

 ginal glands." The conformation of the bays is such as to afford a 

 seat for sustaining a large drop of nectar in position to attract insects 

 to the peril of falling into the pitcher. 



The secondary ridges of N. Lowii are very low and not conspicuous 

 enough to catch the unaided eye except where, at their inner extrem- 

 ities, they become more elevated and end in a tooth beneath which 

 rests the large nectar gland. In N. ijiermis a few low ridges converging 

 on the broad tooth overhanging the gland may be seen. That it is 

 true that the general surface of the peristome affords a precarious foot- 

 hold for insects, ants at least, is as I have already said, doubtful. 

 Knoll found that they can use their footpads, for which, in spite of 

 the minute ridges, the surface is sufficiently smooth. 



Histology of the glaitds. — Brongniart (1824) was the first to notice 

 the glandular character of the inner surface of the Nepenthes pitcher. 

 Treviranus, Meyen (1837) and Korthals (1839) recognized the glands 

 but thought that they were subepidermal, an error corrected by 

 Oudemans (1864). 



The pitchers of Nepenthes are conspicuously supplied with glands, 

 those which serve to attract prey, the alluring glands, and those which 

 secrete the fluid of the pitcher, which is digestive. The alluring glands 

 are to be found on the under surface of the lid {8 — 8) and 

 between the teeth of the inner edge of the peristome {8 — 13). The 

 former are usually dished, biscuit-shaped, sessile glands resting in deep- 

 ish depressions. Some of these glands, in shallower depressions, are 

 to be found in the invagination near the apex of the hd in N. Tiveyi, 



