On Purples or Ear-Cockle in IVheat. 
349 
Bauer observed at Kew, not unfrequently, an injury done to 
the young stem of wheat by one of these worms, which has not 
since been particularly noticed. The illustration given (Fig. 1) 
is from Bauer's drawing. The dark shading on the stronger of 
the two central stems indicates the injury done by the worm ; 
and this is so serious that the vitality of this stem is destroyed. 
The worm producing this disease is smaller than that found in 
the ear gall, is a different species, and probably belongs to'a 
different genus. 
When we examine a spikelet of wheat affected with purples, 
we find that there are present the empty scales or glumes at 
the base of the spikelet, and the two glumes at the base of each 
Fig. 2. — Spikelet of Wheat containing four Pepper-corn Grains 
{inagnified). 
flower. The gall is within these flower-glumes. At its first 
appearance it may be distinguished by its being of a darker 
green than the healthy grain. It darkens in colour until ulti- 
mately it becomes nearly black, and being of a round form it 
has the aspect of a small pepper-corn. But the gall is not a 
simple body. It consists of two parts, more or less completely 
separated. The gall is generally considered to be the grain so 
altered that, instead of the embryo and the store of starch, we 
find a mass of minute worms. The pistil of the wheat, however, 
is a single central one-celled body, whereas the gall consists of 
two opposed parts. Nothing whatever is found within the 
glumes which contain the galls. On examining the gall itself 
we discover that each half is surrounded by a ridge terminating 
in a toothed apex, and that it is sparsely covered on its upper 
and outer portions with short bristle-like hairs. This double 
