210 Report of the Department of Botany of the 



Experiment No. 26 potatoes from five other groceries were com- 

 pared with our Sir Walter Raleigh. The results were the same as. 

 in Experiments 9 and 11. 



In Experiments 59, 65 and 73 ten varieties (three early and seven 

 late) were compared with our own Sir Walter Raleigh. In the last 

 of these the results were as follows: On five varieties (Twentieth 

 Century, Rural New Yorker No. 2, Gold Coin, Sir Walter Raleigh 

 from Honeoye Falls and Sir Walter Raleigh from Geneva) lenticel 

 spotting was severe; on the other six varieties (Carman No. 3, 

 Green Mountain, Ionia, Northern Beauty, Early Rose and 

 Irish Cobbler) there was less, but considerable, lenticel spotting, 

 Irish Cobbler showing the least. Eye injury was severe on all lots 

 without any appreciable difference. In Experiment 88 lenticel 

 spotting was considerably more severe on Gold Coin than on Sir 

 Walter Raleigh and in Experiment 89 Rural New Yorker No. 2 

 was injured considerably more than Sir Walter Raleigh. The con- 

 clusion reached is that varieties may vary somewhat in their sus- 

 ceptibility to injury, but Sir Walter Raleigh is not more susceptible 

 than some other common varieties. 



SOME OTHER POSSIBLE FACTORS. 



In the original case of injury it was observed that tubers exposed 

 on the tops of the crates were severely injured while those on the 

 interior of the crates were but slightly injured, if at all. Even 

 tubers on the sides of the crates opposite the openings between the 

 slats were much less injured than those on the top. This led to 

 the suspicion that some substance precipitated from the air was 

 chiefly responsible for the injury. In Experiment 1 three tubers 

 were placed under an inverted glass dish in such manner that nothing 

 could fall upon them from above. As these tubers were quite as 

 much injured as unprotected tubers further experiments were not 

 made. Whatever the explanation of the greater injury to tubers 

 on the tops of the crates the phenomenon is worthy of note because 

 it shows that tubers on the interior of the crates are much less liable 

 to injury than those on the top. Presumably, there is a correspond- 

 ing difference in the efficiency of the treatment. It is plain that 

 uniform results will be obtained only when the tubers are exposed 

 in very thin layers. 



