328 BOTANICAL GAZETTE [MAY 
effectual. The relative power in the bog plants for absorbing or 
rejecting the various injurious constituents of bog water and bog soil 
is here the controlling factor. This regulatory compensation within 
certain limits, therefore, is of utmost importance in these species, for 
we have here an instance of the fact that while the presence of struc- 
tural modifications is generally regarded as a circumstance in favor 
of a bog vegetation, the most noteworthy characteristic is the ability 
to neutralize the injurious action of the substratum. In so far as 
the adjustments arise through resistance to toxicity and consequent 
drought, one is painfully aware that neither the nature of the drought 
resistance, its origin, its specific governing factors, nor the specific type 
of resistance involved in the adaptation of plants to toxic bog con- 
ditions is known. | 
Another matter of fundamental importance is the degree in which 
this drought resistance in physiologically arid habitats varies, and 
the extent to which it is inherited. That activities are not constant 
but variable in degree and in kind, and that functional characteristics 
in plants are transmitted as effectively as habit of growth, form, 
flower, and seed, is generally admitted. The conditions of life in 
bogs are always active in stimulating or depressing normal functions, 
and they are not without effect upon their degree and character as 
well. The disturbing effect of adverse conditions, if not too severe, 
may be gradually overcome through variations in the degree of 
activity. Often the unfavorable external conditions are conducive 
to the development of a new place-junction, and the immunization 
may extend to the point that would be fatal at the outset. Thus 
plants reared in a gradually intensified toxic solution have reached a 
power of resistance above that of the organisms under normal con- 
ditions. It seems possible to raise forms in which the special resistant 
power becomes a permanent hereditary character. Phenomena such 
as these are remarkable for what they suggest rather than for con- 
clusions that can be positively drawn, since the degree of resistance 
which plants acquire by external or other influences to poisons and 
drought, or to other adverse conditions of life, may be one in which 
the activities are modified, resulting, as has been stated, in a new 
place-function, or one in which the plants succeed in resisting the 
changed conditions through greater elasticity in functions. A 
