218 MASSACHUSETTS AGRICULTURE. 



at least, secondary, or auxiliary causes of its decay. Wo should 

 not forget that the plant we cultivate is not the original potato 

 in its native home, where it doubtless preserves its health from 

 age to age, like other wild inhabitants of the forest. Scarcely 

 any foreign plant has been subjected to a discipline so severe ; 

 to methods of culture s ) diflferent from what nature appointed 

 for this. For some purposes we have changed it for the bet- 

 ter; for instance, in the quantity and quality of its tubers — 

 making them not only an abundant but palatable article of food. 

 But this result may have been attained at the expense of health. 

 Not that the potato is actually running out and is about to die. 

 That seldom occurs to any plants, and especially unlikely is it 

 to occur to those propagated only by seeds; although they may 

 and do degenerate to such an extent as to render their cultiva- 

 tion unprofitable. And this process is hastened by modes of 

 culture diilerent from those by which the plant naturally propa- 

 gates itself. In its wild state, the potato produces small tubers 

 and long tops. We have increased the fruit and diminished the 

 amount of stems and leaves — an operation that may have occa- 

 sioned a great change in its constitutional condition. The 

 energies of the plant are withdrawn from its own nutrition and 

 determined towards the production of fruit to such a degree as 

 to cause its debilitation and decay — an effect with which we 

 are familiar in fruit trees. In a temperate, mountainous coun- 

 try, it probably continues to live in high health. But it has 

 been transported to every variety of climate and of soil, and 

 excessively, and of course, unnaturally, stimulated for the sake 

 of large crops. We know the effects produced on some other 

 plants by a similar course. If a pear tree is over-stimulated, 

 the new wood will not ripen. If wheat is over-stimulated by 

 animal manure, the stalk is rank, tender, liable to rust, and 

 bears no fruit, or very littl ;. Some garden vegetables, so 

 treated, disappoint our hopes altogether. Why may not similar- 

 ly unfavorable results occur in potatoes, by pursuing a course 

 of treatment so foreign from that which nature observes ? Why 

 are potato plants grown on a good but unmanured soil, less 

 liable to rot than others ? Because, in this respect, they are 

 situated more like the wild plant. Excessive stimulation by 

 manure increases the amount of cellular texture, and makes tho 



