METEOROLOGY. 509 



the prognostication and methods of averting frosts, the influence of 

 Avind breaks and orchards upon local climate, the modification of climate 

 in consequence of the removal of forests and the clearing of land, the 

 frequency of droughts, the humidity of atmosi)here as affecting the 

 spread of fungus diseases, and the ability to prognosticate serious 

 incursions of these divseases from a study of their general relations to 

 climate, the liability to hail storms, the nature of the seasonal variations, 

 these, in addition to the subjects already indicated, are some of the 

 living problems which await us. 



Every plant is profoundly modified by the climate in which it is 

 placed; and if any species, therefore, is cultivated over a wide range 

 of territory we must exj)ect to find it widely variable between the 

 extremes of distribution. The same variety of apple, for instance, 

 may lose all its distinguishing qualities and marks through a simple 

 transfer to climates not far removed. A study of the statistics of 

 ai)pie exportations during the next ten years will probably show what 

 States or districts produce fruits of sufficient firmness and long-keep- 

 ing qualities to withstand the journey profitably. And it is not too 

 much to ask of climatology that it shall tell us why the Northern 

 climates develop saccharine elements and high colors, and why the 

 Wisconsin-Minnesota area produces such remarkable waxen and 

 pruinose tints. The influence of climate is nowhere so easily traced, 

 perhaps, as in the business of seed growing. Every seedsman knows 

 that certain climates are not only best adapted to the growth of 

 certain seed crops, but that they exert a profound influence upon the 

 character of the product grown from them. 



The study of all these interrelations of climate and plant life falls 

 into three subjects: Phenology, or the study of the periodic phenomena 

 of plants, a subject which loses half its force and value when con- 

 sidered, as it usually is, without reference to the visible attending 

 features of climate; acclimatization, or a consideration of the means 

 by which plants adapt themselves to climates at first injurious; and 

 secondary variation of plants induced by cliraatal environment. — o. l. 



FAS8IG. 



Phenologic, or thermal, constants, E. Ihne {U. S. JJept. Agr., 

 Weather Bureau Bui. ll,pt.2, Rpt. Inter nat. Meteorolog. Congress, 1893, 

 pt. 2, pp. 427-431). — The problem of thermal constants of vegetation has 

 not made progress since the death of Dr. H. Hoflinann, the indefatig- 

 able exponent of this theory, in 1891. Hoflinann began with January 

 1 as a day of vegetal rest and added together the daily positive maxima 

 of a thermometer fully exposed to the sun, up to the daj" on which the 

 vegetal ijhase in question i^et in, as, for instance, the first blossoming 

 of certain plants. The values obtained by Hoflmann were so constant 

 that he believed he had demonstrated, for Giessen, at least, that there 

 existed between vegetal development and such supply of heat certain 

 legitimate quantitive relations. Although the same vegetal phase may 



