58 STUDIES IN THE VEGETATION OF THE STATE 



The few results obtained from hylophytes or plants of the 

 woods, and poophytes or plants of the meadow and prairie, 

 indicate that the former have a higher limit than the latter. 

 The plant house, it should be remembered, approached nearer 

 to hylophytic conditions, and this favored shade-loving 

 plants. Sun-loving plants on the other hand by being placed 

 under the semi-shade conditions of the plant house tended 

 towards a higher limit than if under more natural condi- 

 tions. The following table gives the results obtained with 

 violets. 



The first species grows in protected places, the second in 

 both sunny and shady localities, and the last in the open 

 prairies. These data as well as others indicate that the 

 limit of hylophytes will average higher than that of poo- 

 phytes. Since shade has the effect of raising the limit of 

 available water it is to be expected that in the structural 

 differences between poophytes and hylophytes the latter have 

 shade adaptations which are of such a nature as will lessen 

 the ability of the plant to withstand drought. 



D. DROUGHT EFFECTS. THE MANNER IN WHICH MANY 

 PLANTS, PRINCIPALLY MESOPHYTES, DIE. 



The plants studied were principally herbs of both monocy- 

 clic and dicyclic types. The behavior of the two types in 

 times of drought is slightly different. Certain drought effects 

 are common to all plants. In general, if the epidermal cov- 

 ering of the plant is uninjured at the beginning, death takes 

 place more slowly and the order in which the different or- 

 gans suffer loss of water is quite constant. If any portion of 

 the plant has suffered mechanical or structural injury, this 



