2 OrrR—LEAF GLANDS OF D1OSCOREA MACROURA. 
‘The presence of nitrogen-fixing bacteria in the glands of 
Dioscorea macroura would appear to constitute a parallel case 
to that of such a species as Psychotria bacteriophila, in which 
the foliicolous micro-organism is a source of nitrogen supply to 
the plant. 
EXPLANATION OF PLATES CXCVII-CXCVIII. 
Illustrating Mr M. Y, Orr’s paper on Dioscorea macroura, 
PLark CXCVIL. Leaf-acumen of Dioscorea macroura, in transverse sectio 
g.g., glands, with en secretory elements oa 
Srey “stained fluid c ; d.d., ducts, leading to the 
upper surface; p.s., paecleiad ‘sheath, en circling the 
d; ac., air chat inel 5 r., raphi ides; v.b., vascular 
br nd s.t., stoma; f., ‘‘flange’’ of tis sue 
Pate CXNCVIIT. Fig. 1 “Apical region 1 of a shoot of Dioscorea macroura, in 
tudinal ction. 
Big spiced eristem 5. ne containing bac - 
: ; t., epidermal scale; raphides. 
Fighs% ieee, culture of the paged ted isolated from the 
glands. of Dioscorea macroura, at the point of 
liquefaction. 
