194 Our Climate and our Wheat-Crops. 
rain, especially during the periods of more active above-ground 
growth and ripening. 
An examination of the last three columns of the Tables will 
bring to light the differences, not between each class of seasons 
and the average, but between class and class. 
Comparing with one another the seasons of both greatest 
total produce and highest produce of corn also, with those of 
comparatively low total produce, but of high yield of grain, it 
will be seen how prevailingly higher was the average mean 
temperature from seed-time to April inclusive, how much lower 
it was in May and afterwards, and also how much greater was 
the fall of rain during May and afterwards, in the seasons of high 
total produce, than in those of high corn only. The last two 
columns, again, show in a striking manner the differences as 
to temperature and rainfall which distinguish, in the one case 
the seasons of high produce of both corn and straw, and in the 
other those of high produce of corn but not of straw, from the 
seasons of unusually defective produce. 
From the foregoing review and comparison of a number of 
seasons of much more than average productiveness, and of some 
of the greatest deficiency within a period of sixty-four years, it 
would appear that mildness, and comparative dryness, of at any 
rate considerable portions of the winter and early spring, 
favouring root development, that is, an extended possession of 
the soil by the plant, and a somewhat early start, have been the 
characteristics of the most productive seasons. These conditions 
fulfilled prior to the period of more active above-ground growth, 
some of the most bulky, and at the same time the most abundant 
grain crops, ripened under considerably higher than average 
summer temperatures also, but more of them ripened in summers 
of scarcely over, or even of under, average mean temperatures ; 
and with, at the same time, but little, if any, less than the 
average fall of rain during that period. Indeed, the facts show 
that, with those favourable early conditions, an abundant and 
high-yielding crop may be obtained with only fairly average, or 
even under average, summer conditions. But there can be little 
doubt that, when high summer temperatures, without excess of 
rain, do succeed upon the favourable conditions of early growth, 
and of plant, above described, the proportion of grain yielded 
by the bulky crop will be the greater. It happens, however, 
that the two both bulky and high-yielding crops which matured 
in the warmer than average summers were the produce of seasons 
before the period of our own observations. The less bulky, and 
somewhat less abundant in grain, but still high-yielding crops 
have, on the other hand, generally had less favourable conditions 
for winter root-development, and for early growth in spring, but 
