1883.] FERTILIZERS. 71 



tion. He said (adding somewhat to what I tliought I had 

 discovered) that it accounted for the corn crop being, in a 

 great many cases, a renovating crop, and also accounted for 

 the fact that it seemed to require, in practice, less of certain 

 fertilizing elements than theory would indicate. 



Now, if you dig up a corn plant, you will find a series of 

 roots extending in every direction through the soil. I have 

 only been able to trace those roots about two and a half 

 feet from the plant, on account of the intersection of the roots 

 of other plants ; but by applying fertilizers at varying dis- 

 tances, and seeing how far they affect the plant, I find that 

 fertilizers applied at a distance of ten or twelve feet from the" 

 corn plant influence the growth of the plant distinctly and 

 visibly. 



Now, these roots seem to *be governed (I use the word 

 seeniy because this is a difficult question to determine) — seem 

 .to be governed in their extension and in their feeding power 

 by the temperature of the soil. It seems, (and this is a case 

 for argument, and perhaps contradiction) — it seems to be a 

 fact, that unless the temperature in summer is sufficient for 

 the fullest extension of these roots, the application of the 

 fertilizers does not have any marked effect upon the crop. 

 So that not only the fertility of the soil, but the temperature 

 of the upper layers of the soil, is an important factor in the 

 production of the crop, and the two conditions seem to have 

 important relations to each other. 



Now, a good many of these facts are inferential that I am 

 giving you now, rather than absolute. We were not able to 

 determine with accuracy the ranges of temperature, as our 

 instruments were insufficient ; yet as all the indications 

 pointed in one direction I feel justified, with this qualifica- 

 tion, in calling your attention to them. 



Now, from this corn plant passes down this tap root, which 

 I indicate on the blackboard, and which I have drawn here 

 in showing the germination of the seed, contrary to the rule 

 of the order to which the corn plant belongs, and contrary to 

 the statements of the books. I called the attention of Dr. 



