428 



EFFECT OF TEMPERATURE UPON FACET NUMBER 



of infection of parasitic fungi demonstrates the same principle here. 

 Simpson and Rasmussen's data for the rate of coagulation of blood 

 give a similar curve. 



Snyder, Fallas, and Elmendorf , dealing with the rate of heart beat of 

 the cat, maintain that this reaction is a logarithmic and not a linear 

 function of the temperature. Groves has applied a similar formula 

 to the length of life of seeds at various temperatures. Loeb has 

 worked out the temperature relations for the total length of life of 

 Drosophila and has applied an exponential curve. He compromises 



TABLE XIII. 



Qio {Calculated from Qt^-h) for the Velocity of Development of the Immaturity Stages 



of Drosophila. 



on the larval-pupal period, however, and admits the straight line re- 

 lations there. 



An important feature of the straight line temperature-rate curve 

 is that it holds only between certain temperatures. As already 

 pointed out for the high temperatures, the rate decreases with increase 

 in temperature above the optimum. Another feature of the straight 

 line curve is that at the lower temperatures the rates are higher than 

 they theoretically should be. The first feature is noted in these ex- 

 periments; the second was not, as the lowest experimental tempera- 

 ture was not the minimum for development. In Table XIII are 

 shown the Qio values for the rate of development as calculated from 



