The bracing weather of Canadian winters is followed by the warmth and humidity of genial summers, under which crops grow in almost tropical luxuriance, while the cool evenings and nights give the plants a robustness of quality which are not to be found in tropical regions, and also make life for the various domestic animals wholesome and comfortable.
This arrangement is adopted in order to prevent excessive luxuriance in the grass.
Thus nature sleeps and dies during winter, to awake in springtime to a life of renewed luxuriance.
But there is no good evidence for an excess of carbon dioxide in the atmosphere - an assumption founded on the luxuriance of the vegetation, coupled with the fact that volcanicity was active and wide-ranging.
The pruning for fruit consists in shortening back the laterals which had been nailed in at the disbudding, or summer pruning, their length depending on their individual vigour and the luxuriance of the tree.