SECRETARY'S REPORT. 57 



the principles of hybridization would have resulted in more 

 vigorous health in all our staple crops. But the practice of 

 breeding in and in, in families, generation* after generation, 

 cannot have been otherwise than prejudicial. 



It is, however, fortunate, that more attention is being paid to 

 this subject, and the advantage of mixing seeds of the different 

 varieties of the same plant is urging upon the public sentiment 

 of the farming community the necessity of its more general 

 adoption. In carrying out the present stimulating process of 

 cultivation, it would be well also for the farmer to be governed 

 somewhat by the capacity of the different crops to sustain vigor- 

 ous life uninjured by its application. Experiments with guano 

 clearly indicate that while some families of plants will bear its 

 application in large quantities — as the cabbage and the most 

 commonly cultivated grasses — others, as the potato and the 

 turnip, fail very rapidly. A striking example of this effect 

 upon the potato was afforded a few years since upon the State 

 Farm, where the deterioration was very great, in the field 

 planted for three successive years with the potato, and manured 

 with an increased quantity of guano each year. 



This consequence is probably brought about something in 

 this way, and the difference in the capacity of different plants 

 to bear stimulation is more apparent than real. The free 

 application of manures highly charged with ammonia, stimu- 

 lates the crop to which it is applied, and causes it to take up 

 from the soil with more readiness the nutritive properties con- 

 tained in it, or increases its appetite for food, as a small 

 quantity of alcoholic liquors taken by man before eating, enables 

 him to eat more freely and digest his food more easily. The 

 increased quantity of nourishment, however, causes a necessity 

 for a much greater expansion of leaves and stalks to cast off the 

 refuse matter of the food and to imbibe more oxygen to vivify 

 its nutritive matter. Hence all plants dressed with such 

 manures, make a vastly increased quantity of leaf and stalk, 

 and as one part of the living system cannot be over stimulated 

 without eventually debilitating some other part, the increased 

 vital force, directed to the parts above named, is in part diverted 

 from the formation of perfect seeds ; hence, those plants of 

 which the leaf and stalk are the valuable portion to the farmer, 



seem to be improved by high cultivation, — as the grasses and 

 8* 



