SUMMARY 21 



than three times the normal rate. The entire series of the 

 above experiments on the effect of temperature on growth 

 was thus completed in less than 15 minutes. 



Summary 



The High IMagnification Crescograph gives automatic 

 record of growth at a magnification of 10,000 times. 

 Growth movement as minute as the sixteenth part of a 

 wave-length of red light can thus be detected. 



Growth appears to be a pulsatory phenomenon. The 

 resultant growth in each pulsation is the difference between 

 elongation and recovery. 



The influence of external conditions on variation of 

 rate of growth is recorded by two methods. 



In the Stationary Method the increase or diminution 

 of the distance between successive dots of the vertical 

 record demonstrates the stimulating or depressing nature 

 of the changed condition. 



In the Moving Plate Method the record is a curve, 

 the ordinate representing growth-elongation, and the 

 abscissa, time. A stimulating agent causes an upward 

 flexure of the normal curve ; a depressing agent, on the 

 other hand, lessens the slope of the curve. 



The Magnetic Crescograph makes possible the demonstra- 

 tion of the principal phenomena of growth and its variations 

 before a large audience, the magnification produced being 

 from one to fifty million times. 



