No. 216.] 601 



the intelligence and the enterprise of the present age. When car€= 

 ful and long continued experiments and observations shall have been 

 made, and scientific research exhausted without any indication of sue* 

 cess, it may be given up in despair j but neither have the efforts to 

 ascertain the cause of the disease been so long continued ; nor the 

 indications of success so unpromising as to justify such a conclu- 

 sion. 



Much has been said and written upon the subject and many theo- 

 ries have been advanced, most of them founded upon careful obser» 

 rations and adhered to with great pertinacity. One discovers aphides 

 among the vines of the diseased plants, and after many examinations 

 he finds that where these abound the tubers decay, and where there 

 are none the tubers are sound. He therefore concludes he has disco- 

 vered the true cause, and gives no credit to any other theory. Another 

 concludes, from his observations, that the disease is caused by fungi. 

 Some attribute the disease to different manures, others to soil or to pe- 

 culiarities of the season. All may be right in one sense ; any or all 

 of these causes may contribute in completing the destruction; but that 

 no one of them is the primary cause is very evident. The very fact 

 that there are so many and so various causes, either of which appears 

 by careful observation to have been adequate, is of itself, sufficient to 

 prove that they are all secondary, and in reality only effects of some- 

 thing beyond, which must still be sought as the true primary cause, 

 through whatever instrumentality it may exert itself. 



There are certain facts probably known to all, which I shall state 

 here, not as anything new, but as the foundation of an argument. 



1st. Potatoes have very generally ceased to produce seed, although 

 blossoms may be seen in abundance ; you may, in some instances, 

 examine large fields in the proper season without discovering a single 

 ball. 



2d. The potato crop is much inferior in quality to what it was 

 formerly. I have known 1000 bushels produced from a single acre, 

 cultivated in a very careless manner, and in some parts of the field I 

 have seen a bushel dug from four hil's. 500 bushels per acre was 

 formerly considered only a fair crop without much care in manuring, 

 planting, or cultivating. What is considered a fair average crop 

 now? 



These facts seem clearly to indicate the loss of vitality in the plant. 

 I infer, therefore, that the potato malady is in consequence of vitality 



