FUNGI. 401 
or less abundance throughout the whole of Great 
Britain; but in the zone where rye is the prevailing 
grain, comprehending all the countries bordering 
on the Baltic, the north of Germany, and part of 
Siberia, it occurs in great abundance, and is often 
a cause of much distress, It is owing to the growth 
of a fungus called Claviceps purpurea (Fig. 48), 
which converts the ovary of the 
grain into an elongated cylindrical 
excrescence, a little curved, and 
somewhat resembling a horn or spur 
projecting from the chaff, and hence 
the rye thus affected is called in 
common language spurred-rye. The 
grain when attacked becomes first 
ie ease soft and pulpy, afterwards it hard- 
purpurea. ens and elongates gradually. It is 
first of a red or violet colour, afterwards lead- 
coloured, and finally black with a white interior. 
It contains so large a proportion of oily inflam- 
mable matter, that it will burn like an almond when 
lighted at a candle. Generally only two or three 
grains in a spike are affected, whose nutritious 
part is thus completely destroyed, and converted 
into a highly injurious substance. When rye is 
extensively cultivated, grains diseased in this way 
often compose a considerable part of the bread 
produced, arid thus not unfrequently give rise to 
2C 
