1898.] PUBLIC DOCUMENT — No. 33. 55 



was found. In the cortex and exterior portions of decayed 

 stems several forms of Micrococcus and also other bacteria 

 were found in abundance. In the interior portions a large, 

 motionless bacillus occurred quite abundantly and exclu- 

 sively, and may have been the primary cause of the rotting. 

 The most probable explanation, however, seems to be that 

 the normal functions of the plant were disturbed and its 

 growth checked by the unusual amount of moisture in the 

 soil. The seed potato, with its supply of reserve food ma- 

 terial for the young plant thus left idle in the soil, naturally 

 rotted away, and this rotting communicated itself more or 

 less to the young stem proceeding from the *'seed." The 

 plant, not being in a condition of vigorous growth to resist 

 this rotting, gradually succumbed to it, and in most cases 

 died. The few plants, as mentioned above, which continued 

 a feeble growth through the season, accomplished this by 

 throwing out roots above the rotted portion of the stem, 

 and thus prolonged a feeble existence. Such plants pro- 

 duced no tubers, and consequently had no value whatever. 



This, then, was the first of the troubles affecting the 

 potato crop in this section. We do not describe or con- 

 sider it as a specific "disease" of the potato, nor do we 

 deem it necessary to consider any treatment for it. We at 

 first recommended removing aftected plants, but doubt now 

 if such a course would have been of any considerable prac- 

 tical value. We are inclined to believe that the trouble 

 was not brought about by any specific or especially destruc- 

 tive organism, but was simply the result of the unusual 

 meteorological conditions of the season, and under such 

 conditions could not be prevented from occurring by any 

 means at our command. 



By July 1, most of the plants which had fallen a prey 

 to the above disease were withered away and dead, while 

 those which had escaped had made a fiiirly good growth and 

 nearly reached maturity in point of size. About July 15 

 several hot, sunny days came on, following a long very 

 rainy spell. In many potato fields on low ground the plants 

 began to wilt and die down. In a large field at the college, 

 situated on a long slope, the plants at the top were un- 



