266 Proceedings of Indiana Academy of Science 



controls were 4 cm. long- while the seedlings from the pressure test were 

 3.6 cm. long. They continued to show some difference for three days 

 after which time all were of the same average size and vigor. 



Corn seedlings 2 cm. long were subjected in the second experiment 

 to 100 atmospheres pressure under the same conditions. After 24 hours 

 the controls averaged 4 cm. in length while the experimental seedlings 

 were 3.2 cm. long on the average. In five days all were equal in size 

 and vigor. Other experiments showed these seedlings to have become 

 clear in three minutes. 



In a third experiment corn seedlings 2 cm. long were placed in a 

 water pressure of 200 atmospheres for five minutes. They became clear 

 in about two minutes. When planted the controls averaged 4.2 cm. while 

 the experimental seedlings averaged 2.8 cm. In seven days all seedlings 

 averaged the same size and were equal in vigor. 



In a fourth series of experiments corn seedlings 2 cm. long were 

 placed in a water pressure of 400 atmospheres for five minutes. Ex- 

 periments showed that they became clear on the average in one-fourth 

 of a minute. In 24 hours the controls averaged 4.1 cm. in length while 

 the test plants were 2.5 cm. long. In 12 days all seedlings were equally 

 large and vigorous. 



Finally corn seedlings 2 cm. long were placed in a water pressure 

 of 600 atmospheres. As nearly as could be determined they became 

 clear on the average in 10 seconds. In 24 hours the controls averaged 

 4.3 cm. and the test plants averaged 2.3 cm. in length. In 18 days all 

 seedlings were of equal size and vigor. The high pressure recorded in 

 the last five experiments was obtained by means of a Geneva Society 

 high pressure pump which will produce pressures up to 1000 atmos- 

 pheres. Melsens" states that yeast will live under a pressure of 8000 

 atmospheres. Corn seedlings can withstand great pressure and recover 

 in a comparatively short time. It is to be noticed, however, that the 

 time of recovery is delayed according to the intensity of the pressure. 



« Melsens. Com)), rend. 1870. Bd. 70 p. 831. 



