2 1 2 Journal of Agricultural Research Vol. xx, no. 3 



In the following experiments the seeds were left for 10 minutes in a 

 o.i per cent solution of formaldehyde followed by a draining period of 10 

 minutes. This strength is equivalent to i pint in 40 gallons of solution, 

 varying in small degree from that commonly referred to as 1 to 40, which 

 means 1 pint of standard formaldehyde solution in 40 gallons of water. 

 As the formaldehyde solution used in the laboratory contained 36.2 per 

 cent formaldehyde, such a dilution would be 1 part of formaldehyde in 

 884 parts of solution, or 0.113 per cent. Unless otherwise stated, the 

 wheat used was Little Club with a low percentage of thrashing injury. 

 After treatment the seed was spread on towels for an hour in order to 

 remove excess surface moisture. The damp seed was then divided into 

 two lots. One lot was put into three Mason fruit jars, holding about a 

 quart each, and sealed. The other lot was put into three boxes, 4 by 5 

 by 6 inches, and left uncovered. They were stirred frequently through- 

 out the experiment. These boxes each contained the same quantity of 

 wheat as did the jars. The original idea in having three samples of each 

 seed lot was to determine the relation of temperature to the injury which 

 was expected to appear in the damp samples. One box and one sealed 

 jar were left in the refrigerator at a temperature of io° C, one of each in 

 the laboratory at 20 , and one in the greenhouse, where the tempera- 

 ture averaged about 30 . For each of the six samples, as in all subse- 

 quent experiments, there was a control of seed dipped in water instead of 

 formaldehyde. 



The following germination tests were made on blotters placed in 

 square pans, 12 by 12 inches, 1% inches deep, kept at room temperature. 

 The pans were covered with square pieces of glass, which made it easy 

 to observe the progress of the germinations. The depth of the pans 

 gave the seedlings a chance to grow erect and more normally than 

 would be the case if they were grown between blotters. Only those 

 seeds were called germinated which produced both a root and plumule. 

 Many which did so were too severely injured to produce plants in soil, 

 but the approximate percentage of these was obtained by contempo- 

 raneous soil germinations (Table II). Soil germinations have the advan- 

 tage of approximating more closely field results. The many advantages 

 in the use of blotters, however, lead the writer to emphasize the fact 

 that they are just as valuable to show the occurrence and comparative 

 degrees of seed injury. In view of the possibility of earlier detection 

 and easier study of such injury, they even may be preferable. The 

 results of the blotter germination tests are given in Table I, 



