Proceedings of the British Association. 345, 
most of the graminivorous birds, can find nothing to support them in 
the winter season ; and, consequently, the migration of the feathered 
tribes is here much more general than in the countries of Europe ly- 
ing under the same parallel. The principal cause of this great dif- 
ference between the climates of the eastern and western districts, 
may be ascribed to the configuration of the coast land, which d 
tains the ice in its bays and gulfs, and this, in melting, materially 
depresses the summer heat. ‘The decrement in the mean annual 
heat, corresponding to the increase in latitude, is greater in North 
merica than in Europe, and there exists a wider difference between 
the temperatures of summer and winter. Dr. Richardson then con- 
cluded this introductory portion of -his report, by details concerning 
the temperatures which had been observed at different places in the 
country under consideration. 
Mr. Rootsey exhibited specimens of sugar, malt, and an ardent 
spirit, which he had extracted from mangel wurzel, and considered 
that this root might, under certain circumstances, be grown to great 
advantage in this country, for the purposes of manufacturing the 
above articles. 
Mr. G. Webb Hall read a communication “ On the Acceleration 
of the Growth of Wheat.” After pointing out the advantages which 
might accrue to agriculture. from the attention given by scientific 
men to certain subjects with which it was connected ; and the abso- 
lute necessity which now existed for making the most extensive and 
careful investigations concerning many points of great importance to 
the success of agriculture, he proceeded to call the attention of the 
Section to a statement of facts, by which it would be seen that the 
usual period allotted to the occupation of the ground for a crop of 
wheat might be very materially abridged. At an average, this might 
be estimated at ten months, though twelve, and even thirteen, were 
not unusual, and eight might be considered as the shortest period for 
the ordinary winter wheat. By a selection of particular seed, and 
a choice of peculiar situation, wheat sown early in March has been, 
on different occasions, ripened before the middle of August, a period 
scarcely exceeding five months. Mr. Hall considers it an unques- 
tionable law of vegetation, that the offspring of a plant of early ma- 
turity itself, seeks to become so likewise, even when placed in un- 
propitious circumstances, and that it recedes with reluctance from 
the ha of its parent. Hence the seed of a crop which has: 
been ripened in five months has a better prospect of producing 
Vou. XXXI.—No. 2. 44 
