250 THE GEOGRAPHY 



Faroes have a mean winter temperature of 37 4', and the 

 Shetland Islands 39 12'; but the mean summer heat of 

 Drontheim amounts to 60 5', while in the Faroes only to 

 50, and in the Shetlands to 52 4'; and therefore neither 

 Wheat or fruits ripen, although the latter will bear a much 

 more severe winter temperature than 24 34'. At Moscow, 

 which has an excellent vegetation, the mean winter tempe- 

 rature is 13 5 r. The 1 5 degrees more northern Mageroe, 

 situated quite beyond the limits of cultivation, has a mean 

 winter temperature of 24; that of Astracan, 10 degrees 

 more south than Moscow, and where both the Vine and 

 Maize flourish, is the same. But the mean summer heat 

 of Mageroe is 42 55', that of Moscow 61 4', and that of 

 Astracan 71 36' ; and it is altogether the heat which prevails 

 during the season of vegetation which determines the con- 

 ditions of the plants. In annual plants, or to speak more 

 correctly, in summer plants, the matter is self-evident ; and 

 perennial plants mostly enter in autumn into a condition 

 of inactivity, an actual hybernation, which allows of their 

 suffering severe degrees of cold without evil results. 



But in spite of all the researches we have not nearly 

 attained the mark ; it will be the duty of the next genera- 

 tion to break up the divisions of mean summer and winter 

 temperature still further, into the mean temperature of the 

 single months, since the half-yearly sections are far too 

 large to admit of an accurate comparison of the vegetative 

 periods. Very probably the result will be, not merely to 

 discover what temperature the plant generally requires 

 during its stage of vegetation, but also, essentially, how this 

 temperature is distributed over the epochs of germination, 

 growth, blossoming, and maturation of the fruit. Here, 

 as everywhere else, the acute Naturalist sees endless labour 

 before him, and only the ignorant prater thinks that he 



