placed deeper in a nutrient 

 solution than they had been in 

 the sand. The base of the 

 stem split in those specimens 

 reviously exposed to the air. 

 In the souring of crops in 

 fields planted with horse 

 beans, peas, vetches, etc., 

 the base of the stem is rup- 

 tured at times above the 

 I)laces where the (rotted) 

 roots arise, and it is found 

 that a spongy, loose tissue 

 protrudes from the torn place, 

 as in the bean here illus- 

 trated. 



All these phenomena have 

 one characteristic in common 

 — that they are initiated only 

 when, after a considerable 

 period of normal develop- 

 ment, or still more after a 

 prexious dry period, an un- 

 usual supply of water is given 

 suddenly. If the plants are 

 in contact with water from 

 the beginning of their de- 

 velopment, they adjust them- 

 selves to their surroundings. 

 The same adjustment can be 

 observed especially in those 

 varieties which develop in 

 water as well as on dry land. 

 Levakoffski's' experiments on 

 Epilobium hirsutum, Lycopus 

 europaeus and Lythrum serve 

 as examples. The compari- 

 son of water and land speci- 

 mens shows that in the water 

 plants, two rows of colorless 



1 Levakoffski. De rinfluence 

 de I'eau sur la croissance de la 

 tig-e etc. Cit. Bot. Zeit. 1875. p. 696. 



Fig. -4 2. Bean plant split at the base as the result of excess 

 of water, The torn place has scarred over. 



