1906] TRANSEAUBOGS 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, i foot 

 wide and a half foot deep (6oX3oXi5 cm ) 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 feet (i2 m ) 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 (i) that humous acids (acidity 

 varying from .0005 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; 



