238 МВ. А. BARCLAY ON THE LIFE-HISTORY 
but a little lighter in colour, especially the yellow halo. These attacked areas of the 
leaf-blade are somewhat thickened. Тһе petioles are also frequently attacked, when they 
become brown in colour and thickened. Тһе stem is sometimes, but not often, attacked. 
In this ease the whole stem is uniformly enlarged; and the largest stem-hypertrophy 
I saw was 1:5 centim. in length by 4 millim. in diameter. 
Тһе spermogonia are of the usual character, but sometimes irregular in shape (fig. 23), 
and are formed only on the upper leaf-surface. ‘They precede the eruption of the ecidia 
by a very short interval; and, indeed, I have often seen ripe spermogonia on the upper 
leaf-surface whilst the lower surface bore young, still unopened peridia. They are deeply 
set, their bases reaching down to the inner level of the palisade-cells. "They measure 
about 126 и in depth by 157 и in breadth, and have a tuft of paraphyses protruding about 
63 „ from the mouth. 
The ecidia burst always from under a leaf-surface. They contain very brilliant 
orange-red spores, and are deeply sunk within the laminal tissue, their bases resting 
often on the inner ends of the palisade-cells (Pl. ТУТ. fig. 22). 
The peridia are very short tubes, densely packed together, bursting at the summits in a 
stellate manner. Тһе tube consists of a single layer of flat cells, more or less hexagonal, 
and measuring about 26 x 22 и (Pl. LVI. figs. 19 & 20, b). These cells are thick-walled, 
and contain orange-red oil-globules in their cavities. They are arranged in an imbricate 
fashion, the upper end of each cell overlapping the lower end of the cell above internally 
(Pl. ГУТ. fig. 22). 
The mycelium is colourless and ramifies between the parenchyma-cells. Тһе hyphe 
are remarkably straight, and not so convoluted as usual. In the leaf-blade they are 
most numerous among the spongy cells, but twigs run up also between the palisade-cells 
to the upper epidermis-cells ; and haustoria, in the shape of simple small tubular intrusions, 
are formed abundantly in the palisade- and upper epidermis-cells. Тһе mycelium gives 
rise to hypertrophy of the spongy cells; but the palisade-cells retain their normal 
proportions and shape. In the stem mycelial filaments may be seen everywhere, but 
sparingly in the central pith-cells: here the mycelium is most abundant in the cortical 
parenchyma-cells, which are very considerably hypertrophied. Haustoria similar to 
those described above are met with in these cells. 
The ecidiospores are of avery brilliant orange-red colour, oval, covered externally with 
shallow tubercles, and measure when fresh 26 х 20:2 и on an average (РІ. LVI. fig. 20, а). 
They do not germinate readily in water, but when they do they throw out straight 
unbranched tubes with a decided tendency to spring up into the air instead of into the 
water. Into these tubes the brilliantly coloured contents of the spore wander. Each 
spore has from 7 to 8 germ-pores. The spores are turned deep blue by sulphuric acid. 
TELEUTOSPORIC STAGE. 
Uredospore pustules appear in July, when the ecidial stage is in existence. They are 
AVERY, brilliantly orange-red, mostly epiphyllous, but largely also hypophyllous. Pustules 
primarily break out from the upper leaf-surface, but afterwards the same mycelium 
produces pustules below also. They are round or slightly oval, and very numerous. 
