69 
to its growth, the diseased spikelet stood lower than the sound 
ones, and hence was often hidden from view. Generally the spikes 
were diseased throughout. Exceptions, however, were noticed in 
which a few of the lower spikelets only were touched, and the others 
~ were green, or the greater number were affected, and a few of the 
upper ones were intact. In one instance the upper sound ones 
were in blossom, indicating progressive development in spite of the 
. disease below. This was marked for special study, and will be 
noticed further on. On the first strong wind occurring, the 
_ fungus-spores with the fibrous wreck of the spikelets were 
- dispersed, leaving only a bare rachis, the culm and leaves 
_ withering gradually. The (4) crop could not from position be.so 
extensively observed. The appearance of the Smut bore the same 
. relation to the period of blooming as in (a), and its progress was 
_ alike in all respects. The disease appeared in (c) the Barley 
section, about the same time as in (a), but was more limited; 
here the affected spikes became more conspicuous, especially after 
dispersion of the spores and wreck of the grain, for the rachis took 
a vertical position above the drooping spikes, when relieved of its 
weight. Soon after the appearance of the Smut, the Wheat- 
_ blades became much affected by uredo linearis, the Summer-rust. 
_ The destruction of the spikes of Wheat by the Smut was ascer- 
_ tained to be effected before its protrusion from the enveloping 
_ sheath. Several suspected blades that were slow to open were 
unrolled, and the blighted Ear was found within, each spikelet 
_ forming a greyish black compressed ovoid bead still unruptured ; 
_ this condition was frequently noticed in the Barley spikes, after 
protrusion, the tougher cuticle apparently delaying the disintegra- 
_ tion on exposure to the air. The protrusion of the Ear is effected 
_ by the pushing force of the growing stalk, and the expanding 
action of the swelling spike. By the death of the Ear the 
_ expanding influence is absent, and the pushing power may be 
_ weakened. Not only is the blighted spike delayed in appearing, 
and only comes forth when the sound Ear is in bloom; but it 
_.often happens the tip of the spike catches in the unopened 
_ contraction of the sheath where the leaf-blade is given off, and the 
a stalk continuing to grow, a curved form is produced i in the spike 
often with a sharp angle at its junction with the stalk. In Barley 
he long awns projecting above the rachis adds to the difficulty 
and makes the result more frequent under these circumstances. 
_ The same thing happens with sound but weakly developed spikes, 
or by the accidental cause of the tendril of a vetch stran gling the 
upper part of the sheath. Though the disease first developes and 
matures in the lower spikelets, from the upper part being first 
_ exposed to the air, this part is the earliest to disintegrate; and 
thus instances were met with in which a bare rachis existed at 
Zz. he upper part, whilst the form of the lower spikelets was main- 
tained ; or the bare end was protruding from the sheath, whilst the 
_ lower ‘spikelets within peramed, their outward shape by the. 
