Illustrations of the Structure and Life-history 
of Puccinia Graminis, the Fungus causing 
the ‘ Rust ' of Wheat. 
BY 
H. MARSHALL WARD, M.A., F.L.S., F.R.S., 
Fellow of Christ's College , Cambridge, and Professor of Botany in the Forestry 
School , Royal Indian College , Cooper's Hill. 
With Plates XI and XII. 
T HE accompanying figures, in illustration of the biology 
of the Fungus which causes the Rust of Wheat, have 
been prepared in continuation of the series of illustrations of 
life-histories of parasitic fungi which I was commissioned to 
make for the Science and Art Department, South Kensing- 
ton, and the first of which (on the fungus of the Potato- 
disease) appeared in the Quarterly Journal of Microscopical 
Science in 1887 h As before, the text is only to be regarded 
as a description of the figures in the plates, and I have pur- 
posely avoided any reference to matters of theory, and also to 
several points of interest which have cropped up during the 
investigation. 
Fig. 1 (PI. XI) was drawn from a longitudinal section through 
a still green leaf of the wheat, attacked by the fungus in what 
is termed the Uredo- form. It shows the epidermis, to the left 
above, with a stoma in nearly median longitudinal section. 
Below this are several mesophyll-cells of the leaf, with their 
curiously sinuous outlines, and the large intercellular spaces 
between them ; these cells contain chlorophyll-corpuscles. 
To the right below is part of a vascular bundle in oblique 
1 Q. J. M. S., yol. xxvii. part 3. p. 413. 
[Annals of Botany, Vol. II. No. VI, August 1888.] 
Q 
