313 



they will be found, together with directions for their use, in PART ONE 

 (pp. 318-327). Schemes for any necessary modification of the tabulated 

 values are explained in PARTS TWO and THREE. 



It will readily be seen that this indirect method of the application of 

 weather data to the needs of horticulture presupposes the making and 

 compilation of accurate and comprehensive meteorological data at numer- 

 ous stations, each representing a definite district, and their continuous 

 translation into terms of the rate of development of the insect. This is 

 work for an expert with ample time at his conunand for such surveys, and 

 inferences to be drawn as to the time and nature of practical control 

 measures must have timely distribution by him to those concerned. Such 

 conclusions and directions are at present formulated and distributed from 

 time to time by the entomologists of the Natural History Survey, mainly 

 through the farm advisers of the various counties of the state, but it is to 

 be hoped that these farm advisers will presently become sufficiently 

 acquainted with the method and sufiicicntly practiced in its application to 

 be mainly independent in its use, subject only to the general supervision 

 and advice of the entomologists. 



It is also to be hoped that other entomologists will find themselves 

 interested and enabled to continue investigation in this fruitful field, thus 

 bringing to positive conclusion many matters left more or less in doubt in 

 the present paper and attacking other problems here left untouched. To 

 all such, it is believed that the third, especially technical, part of Dr. Shel- 

 ford's discussion will have a high and indeed an indispensable value. 



Stephen A. Forbes. 



I 



