GEOGRAPHY OF PLANTS. 489 



THE TEMPERATURES REQUIRED BY THE AMERICAN GRAPE-VINE. 



The following table will exhibit the time of leaiing, blooming, and ripening 

 of twelve of the new varieties of native American grapes at Waterloo, New 

 York, latitude 42° 55' north, longitude 76° 50' west, in the summer and 

 autumn of 1862, which appears to have been a favorable season, unattended by 

 any unusually unpropitious circumstances. Tliis table, also, shows the number 

 of days from leafing to blooming, the average temperature of each period, and 

 the sum of the mean temperatures for the same, derived from a neighboring 

 meteorological station; also, the number of days between blooming and 

 maturity, the actual average temperature, the sum of the mean temperatures for 

 the same, total number of days from leafing to ripening, average temperature 

 of the entire epoch of growth and aggregate of heat required to perfect the fruit. 

 We have superadded a column of time of stoning, based upon the time of color- 

 ing, dating three weeks anterior to the latter appearance, which is very nearly 

 correct. From the latter epoch we have calculated the temperature for the 

 month following, from actual observations, and have appended remarks upon 

 the quality of the product. 



The attentive observer of this table will find much therein to interest and 

 instruct He will remark the order in which the varieties are arranged is not 

 based upon their respective early leafing or blooming, but upon the order of 

 ripening and the aggregate amount of heat required for the entire cycle of 

 growth ; that while the average temperature for the term from leafing to 

 blooming remains about 59°, the number of days required by the different 

 kinds varies but slightly, except in the Clinton and Isabella. The amount 

 of heat received during this stage ranges from 1893.33° in the Clinton to 

 2678.66° in the Delaware ; also, that the period comprised between bleoming 

 and ripening varies much more widely, from 77 days, required by the Dela- 

 ware, to 111 days, which were inadequate to the maturation of the Anna. He 

 will perceive that the varieties first in order enjoy during this period the favor- 

 able temperature of about 68°, which appears adequate to their ripening, and 

 that the- sum of heat received during this period is generally much less than 

 that required by those lower on the list, which do not indeed properly mature, 

 and whose mean temperature is lower because of the prolongation of their 

 period of growth into a cooler season. 



Proceeding further, we note the total number of days required from leafing 

 to maturity to vary from 122 days in the Delaware and Hartford Prolific to 

 154 and beyond in Anna, which did not ripen. The average temperature for 

 the entire period of growth varied but little, but the entire amounts of heat are 

 widely different. Finally, that those which attained the highest perfection 

 enjoyed the highest heat during the month following the commencement of the 

 stoning process, and that those whose temperature at this time fell to 67° or 

 thereabouts were of but indifferent Quality, and that those which were below 

 66° did not ripen at all. 



