STRUCTURE OF BAMBOO LEAVES. 77 
section of the parenchyma-sheath is shown on Pl. 11. fig. 7 (Phyllostachys); fig. 12; Pl.12. 
figs. 19, 14, 16, 17 (Dendrocalamus); Pl. 13. fig. 23 (Dinochloa) ; figs. 29, 30; Pl. 14. 
fig. 31 (Melocanna) and fig. 39 (Chusquea); while the longitudinal section appears from 
Pl. 11. fig. 5 (Arundinaria Hookeriana) and Pl. 14. fig. 35 (.Melocanna). The inner sheath 
(“ Mestomscheide," Schwendener), which is wanting in many Grasses, is always present in 
Bamboos. Like the parenchyma-sheath it consists of elongated cells, the end-walls of 
which are either square or pointed. The walls are thick and I have always found them 
strongly lignified; they are pitted like those of the sclerenehymatous fibres. "This inner 
sheath often consists of several layers of cells. 
In Bamboos the number of slender or intermediate nerves between two stout nerves 
varies from 1 to 10, the usual number being 5 to 8. In most species the two classes 
ean readily be distinguished, but there are exceptions. Ettingshausen (p. 5) has made 
an attempt to classify grasses according to the greater or less distance between 
intermediate nerves (Zwischennerven). For the classification of all species this character 
is hardly suitable, but in some cases the distance between longitudinal nerves will be 
found useful to facilitate the identifieation of species when leaves only are available. 
I find it convenient to count the number of nerves, secondary and intermediate, in a 
quarter of an inch. Only full-grown leaves should be selected and the nerves must be 
counted in the middle, halfway between base and tip. They are often closer together 
near the edge of the leaf, hence an average should be struck between countings near the 
edge and the midrib. Leaves grown under exceptional circumstances, for instance in a 
hothouse, are apt to be irregular and should be avoided. As the leaf gets narrower 
towards the tip, a number of nerves disappear, and though it is safer to count in the 
middle, the distanee between the nerves remains very much the same. 
The point which I desire here to make clear is, that in some species the longitodiuid 
My description of Bamboos in my *Indian Trees" 
nerves are further apart than in others. 
The following list of some of the more 
gives the mean distance for the different species. 
noteworthy species may seem to illustrate what has been stated :— 
PO" Width of leaf in the - Nerves in 
Te middle (in inches). } inch. 
Arundinaria falcata, Nees o soo 6 1 te ts i- À 36-45 
A. Hookeriana, Munro 4-14 21-24 
A. spathiflora, Trinius à l- } 24-30 
A. Falconeri, Benth. & Hook. "M (c Pasco l- i 21-27 
A.jaunsarensis, Gamble. < s sore om oro c 3 33-42 
Bambusa Tulda, RBoxb; : -o o 9 9 ue s 9 30-43, 
B. khasiana, Munro. . ee 09 ea 1-14 18-21 
B. Balcooa, Roxb. 1-2 PN 
B. arundinacea, Willd. : 1 30—45 
Dendrocalamus Tiigi siii Kui : 1 25-30 
3 2-4 20-28 
D. giganteus, Munro. . . Lag es gies . 
Teinostachyum Wightii, Beid. ao 16-20 
Melocanna bambusoides, Trinius . . . 
SECOND SERIES.—BOTANY, VOL. Vil. 
