348 



NINETEENTH REPORT. 



Pinus resinosa tap root lengths, as indicated by the preceding theo- 

 retical curves, would, at 10-day intervals, be as follows: 



I. II. III. IV. 



June 28 1.7 cm. 1.7 cm. 1.7 cm. 1.7 cm. 



July 8 1.9 2.2 2.6 2.9 



July 18 2.2 2.7 3.5 4.2 



July 28 2.4 .3.2 4.4 5.5 



August 7 2.6 3.7 5.3 6.8 



August 17 2.9 4.3 6.2 8.1 



August 27 3.1 4.8 7.1 9.4 



September 6 3.4 5.3 8.1 10.7 



September 16 3.7 • 5.8 9.0 12.0 



September 26 3.9 6.3 9.9 13.3 



The maximum and minimum temperatures of air just above soil as 

 registered in the Pinus strobus experiment are given below. These tem- 

 peratures are Fahrenheit and are given simply to show the general con- 

 ditions under which the various beds grew. Cf. Tables I, II, III, IV. 



Date. I. II. III. IV. 



July 13 92 max. 96 max. 106 max. 106 max. 



62 min. 60 min. 53 min. 62 min. 



July 14 99 99 102 103 



67 65 62 67 

 July 15 None taken. 



July 16 102 103 111 115 



71 73 65 72 

 July 17 97 96 106 105 



69 66 62 67 



July 18 101 101 112 114 



72 68 66 68 

 July 19 101 104 111 lit 



73 71 68 74 

 July 20 93 92 95 94 



68 64 62 76 

 July 21 95 100 107 107 



62 59 56 60 



July 22 99 102 109 107 



62 61 58 67 



July 23 100 103 112 115 



64 61 57 69 

 July 24 103 104 107 118 



67 64 67 65 



July 25 103 106 111 118 



67 64 62 66 



July 26 101 104 112 116 



71 68 63 70 



July 27 103 106 111 112 



73 70 68 73 



July 28 ? ? . Ill 112 



68 70 



July 29 108 .110 112 118 



75 73 70 73 



July 80 103 105 110 111 



77 75 72 79 



July 31 92 95 106 105 



62 60 63 57 



August 1 93 92 103 102 



52 46 48 44 



August 2 95 95 106 105 



65 62 66 58 

 August 3 95 95 100 97 



65 62 64 59 



August 4 100 100 110 108 



73 71 74 69 

 August 5 95 98 105 106 



74 72 75 69 

 August 6 98 100 107 106 



77 75 78 78 



August 7 93 94 102 101 



74 71 77 68 



August 8 86 93 102 106 



62 58 61 55 



August 9 69 91 103 101 



61 58 61 55 



August 10 87 89 97 96 



71 70 72 68 



August 11 98 89 100 99 



56 54 56 51 



