144 HOW CROPS GROW. 
fluences tne relative development of the organs of a plant. 
In a dry season, plants remain stunted, are rougher on the 
surface, have more and harsher hairs and prickles, if these 
belong to them at all, and develope fruit earlier than 
otherwise. In moist weather, and under the influence of 
rich manures, plants are more succulent, and the stems and 
foliage, or vegetative parts, grow at the expense of the re- 
productive organs. Again, different varieties of the same 
plant, which are ofteu quite unlike in their style of devel- 
opment, are of necessity classed together in our table, and 
under the same head are also brought together plants 
gathered at different stages of growth. 
In order that the wheat plant, for example, should always 
have the same percentage of ash, it would be necessary 
that it should always attain the same relative development 
in each individual part. It must, then, always grow under 
the same conditions of temperature, light, moisture, and 
soil. This is, however, as good as impossible, and if we 
admit the wheat plant to vary in form within, certain lim- 
its without losing its proper characteristics, we must ad- 
mit corresponding variations in composition. 
The difference between the Tuscan wheat, which is cul- 
tivated exclusively for its straw, of which the Leghorn 
hats are made, and the “ pedigree wheat” of Mr. Hallett, 
(Journal Roy. Ag. Soc. of Hng., Vol. 22, p. 374,) is in some 
respects as great as between two entirely different plants. 
The hat wheat has a short, loose, bearded ear, containing 
not more than a dozen small kernels, while the pedigree 
wheat has shown beardless ears of 8? inches in length, 
closely packed with large kernels to the number of 120! 
Now, the hat wheat, if cultivated and propagated in the 
same careful manner as has been done with the pedigree 
wheat, would, no doubt, in time become as prolific of grain 
as the latter, while the pedigree wheat might perhaps with 
greater ease be made more valuable for its straw than its 
grain, 
