1906] TRANSEAU—BOGS OF THE HURON RIVER VALLEY 25 
repeated with corn, white lupine, and bean under similar conditions, 
with similar results. The greater development of roots in the case 
of the warm bog water may be due to the presence of a poison in very 
minute quantities; but this I have been unable to prove. 
(2) A third culture was then made in which five plants of corn 
were grown in each of the four water culture conditions, and in 
addition in four similar conditions, using a mixture of sphagnum 
and peat for the substratum. Wooden boxes 2 feet long, 1 foot 
wide and a half foot deep (60 X30 *15°™) were constructed, and two 
were lined with galvanized iron. The bottoms of the unlined ones . 
were perforated so as to allow of easy drainage. The lined boxes 
served for the undrained conditions. Further, in one of the drained 
and in one of the undrained boxes, 40 féet (12™) of glass tubing, 
bent into coils, the joints: ‘being connected» by rubber tubing,were 
arranged so that a constant flow of cold water, for lowering the 
temperature, could be maintained. The water level in the undrained 
bog substratum was kept just below the surface. The water was 
obtained from the bog at First Sister Lake, but occasionally all were 
watered with distilled water. The amount added to each box was 
practically the same. In order to keep the solutions in the water 
culture jars at the same acidity as in the undrained boxes, the water 
was siphoned off and transferred once a week. Care was taken in this — 
transfer to aerate the water in the boxes as little as possible, while 
that of the jars was aerated at irregular intervals by means of a 
bulb. There were thus produced eight conditions, in which it was 
possible to test the effect of the acidity of the bog water, of aeration 
(drainage) of the substratum, and of low temperatures. As a result, 
it was found that the growth of roots and leaves was best in the 
warm bog water, in the warm nutrient solution, and in the drained 
warm peat substratum. Reduction in size of both roots and leaves 
occurred in the cold bog and nutrient solutions, and in the drained 
cold and undrained warm and cold peat substrata. But the plants 
in the undrained cold peat showed the most marked reduction in 
size. The conclusion was reached (1) that humous acids (acidity 
varying from .coo5 to .0023 normal acid) have no effect upon corn 
in the matter of leaf and root development; (2) that low temperature 
and lack of aeration of the substratum both cause reduction in size; 
