GEOGRAPHY OF PLANTS. 493 



ance of tlie seeds, and at this period it is absolutely necessary that there should 

 exist a month, the mean temperature of which does not fall below 66.2° Fah- 

 renheit, a fact sufficiently demonstrated by the table of European localities, 

 where failure or success attend attempts to cultivate the wine grape at certain 

 places, respectively, as set forth on page 480 of this volume. These results 

 are again confirmed at Waterloo, New York, where, by examination of our 

 table on page 490, the natural product of calculations from the data in our 

 possession, without effort to force an agreement, we find that the two varieties 

 which did not ripen at Waterloo were the Catawba and the Anna, whose 

 month of stoning fell below 66.2° Fahrenheit, or to 65.62^, and 50.61°, or to at 

 least 62°, as shown by another calculation, respectively. 



By judicious application of thd principles deduced from the foregoing, the 

 extent of a growing season may be readily, and, perhaps, accurately defined, 

 and all those varieties of grapes and other fruits whose demands for heat fall 

 within the limits designated, other cu-cumstances being favorable, be success- 

 fully grown. Tables of aggregate temperatures might be constructed either on 

 the principle observed in the table of leafing, blooming, and ripening, or on 

 that noticed above as employed by De CandoUe, which would serve as valuable 

 guides in practice. 



GENERAL RULES FOB DETERMINIIVG THE FITNESS OF A DISTRICT IN THE UNITED 

 STATES FOB THE GROWTH OF CERTAIN VARIETIES OF VINES. 



The following rules derived from a close study of the requirements of the 

 various native grapes will be found very useful to many inquirers M^ho are at 

 a loss to know the fitness of their district for their cultivation, and in connexion 

 with the following tables may serve instead of an isothermal and hyetographic 

 or rain map prepared to accompany a former article on the " Climatology of 

 American Vines," but not published. 



1. Those places which have a summer temperature of 66.5°, a hot month 

 of 70", and a September of 60°, will ripen the Delaware, Clinton, Perkins, 

 Logan, King, and some other very hardy varieties. The temperature of their 

 growing season corresponds to a mean of 65° and upwards, and an aggregate 

 of heat of about 8,000° Fahrenheit. This district includes many parts of 

 New England and New York, northern Pennsylvania, northern Michigan, 

 Wisconsin, and Iowa. 



2. Those places which have a summer of 70°, a hot month of 72°, and a 

 September of 63°, will ripen the Concord, Hartford Prolific, Diana, Crevelling, 

 &c. Their season of growth corresponds to a mean of 67°, and an aggregate 

 of 8,500° and upwards. This district covers part of the southeast and south coa.st 

 of New England, valleys of Hudson and Mohawk, neighborhood of the minor 

 lakes in western New York, southern border of Lake Ontario, southern Michi- 

 gan, southern Wisconsin, &c. 



3. Those places which have a summer of 72°, a hot month of 73°, and a 

 September of 65°, will ripen the Isabella. Their growing season corresponds 

 to a mean of 70°, and an aggregate of 10,000° of heat. They are not found 

 in the State of New York, except in the southeast extremity, lower valley of the 

 Hudson, and near some of the minor lalces, but appear on the southern border 

 of Lake Erie, in northern Indiana and northern Illinois. 



4. Those places which enjoy a summer mean of 73°, a hot month of 75"°, 

 and a September of 65°, will ripen the Catawba. Their growing season 

 corresponds to a mean of 72°, and an aggregate of 11,000°, They are not 

 found north of New York city and vicinity, or the southeastern counties of Penn- 

 sylvania, middle New Jersey, or southern Ohio, Indiana, Illinois, and Missouri. 



5. Those places which bask under a glowing summer of 74°, a hot month 

 of 75°, and a September of 75', as at Los Angeles, in California, other cir- 

 cumstances being favorable, may ripen the most tender European wine grapes 

 to perfection. 



