138 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 3 



degrees of moisture at each degree of temperature were known, it 

 should be possible to give a valuation for each degree of temperature 

 which when the total equalled 100% or 1 would give the true physio- 

 logical constant for the stage of growth or activity concerned. Such 

 a proceeding would, of course, be entirely impractical except in the 

 case of an insect of great economic importance in the control of which 

 the application of such data would have immediate practical value, 

 as in the case of the cattle tick. But if we are to deal with tempera- 

 tures in relation to entomological phenomena, and are to give the mat- 

 ter any study at all, we may as well seek to have an understanding of 

 the principles concerned even though we may not always use them in 

 an exact manner. How closely accumulations of tertiperature values 

 made by the above method will agree with the observed phenomena 

 under varying conditions the writer has not had opportunity to deter- 

 mine, though the computations are now being made. The method 

 seems, however, to be much more exact from a theoretical standpoint, 

 than any heretofore advanced, and whether it includes all the factors 

 necessary to determine a thermal constant or not, it is evident that 

 some such process of computing the values of each degree of tempera- 

 ture from a curve established for each stage of growth, and by which 

 they are reduced to a common basis, must be used before there is 

 any possibility of securing a thermal constant for any given phenome- 

 non of growth where subject to varying temperatures. 



Authors Cited 



1. Abbe, Cleveland. First Report on the Relations Between Climate and 



Crops. Bulletin 36, U. S. Weather Bureau. 1905. 

 la. Abbe, C. In First Report U. S. Entomological Commission. Thermal 

 Constant for Locust Eggs. p. 425-432. 1878. 



2. Bachmetjew, P. Experimentelle Entomologische Studien, I. Temperatur 



verhaltnisse bei Insekten. p. 160. Leipzig. 1901. 

 2a. Bachmetjew, P. Experimentelle Entomologische Studien. vom 

 physikalisch-chemischen Standpunkt aus. Zweiter Band. p. 999 + CVIII, 

 Pis. 31. Sophia. 1907. 



3. Bellati, M. e Quajat, E. Sur 1' eclosion anticipee des ceufs der ver-a-soie. 



Arch. ital. Biolog. XXV, Fasc. IL 1896. Cited by 2a. 



4. Candolle, A. P. de. De la germination sus les degres divers de tempera- 



ture constante. Biblioth. Univ. et Revue Suisse, Tom. XIV, p. 

 243-282. Cited by 1. 



5. Davenport, C. B. Experimental Morphology. Vols. II 1897-99. New 



York. 



6. Duvel, J. W. T., Cold Storage for Cowpeas. Bull. 54, Bureau Entomology, 



U. S. Dept. Agr. p. 49. 1905. 



7. Girauit, A. A. and Rosenfeld, A. H. Pysche, XIV, p. 45-57. 1907. 



