1914] 



Guy J Vest Wilson 



20- 



each pot. After germination these were divided to form two com- 

 plete series upon which observations were made. Photographs were 

 made as developments suggested (Plates 3-5). 



Experiment i. Buckwheat. The first culture was photo- 

 graphed when the seedlings were about four days old, again after 

 the lapse of a week, and lastly at flowering time. A comparison of 

 the photographs shows in the early part of the period of growth 

 (Fig. 1) a slight acceleration in the pots heated to 95°, in the one 

 heated to 135 it was somewhat retarded, and in the one heated to 

 1 75 there was marked retardation in germination and stunting in 

 growth. The plants on the soil heated to the higher temperatures 

 were increasingly more unhealthy in color and decreased in vigor. 

 After the lapse of a week the same relative conditions were still 

 apparent ( Fig. 2 ) . At flowering time the results were quite marked 

 (Fig. 3) . The plants in the pot heated to 95 ° came into bloom about 

 five days earlier than did the check, and bloomed more profusely. 

 The photograph was taken about a week after the first flowers ap- 

 peared. At this time the check was second in vigor to the growth 

 in the pot which had been subjected to a heat of 95 °, while the 

 plants on the soil heated to 135 ° lacked vigor and only one plant 

 produced flowers, and that sparingly. The plants on the soil which 

 had been heated to 175 produced no flowers, were of low vitality, 

 and much stunted in growth. The following table shows in detail 

 the results of this set of cultures. 



From this it appears that, so far as buckwheat is concerned, 

 slight heating of the soil is beneficial, while high heat retards growth 

 very seriously, and produces weakened plants. 



Checks were run on this experiment and the results agreed with 

 those given above, except that none of the earlier cultures were kept 

 until flowering time. No fungous disease appeared on the plants, 

 although various fungi developed on the soil. While no especial 



