i 4 HORTICULTURAL SOCIETY OF NEW YORK. 



HERBACEOUS GROUNDS. HEMLOCK GROVE. 



n Total Number of Total Number of 



Exposure Hours Exposure Hours 



Dec. 17 to 24, 1900 + 1.50 74 +1.27 48 



2.25 94 +1.28 120 



Dec. 24 to 31 +1.50 90 +.90 65 



.85 78 .90 103 

 Dec. 31 to Jan. 7, 1901 + .80 68 -f .50 40 



2.10 100 +2.84 128 



Jan. 7 to 14 -h .80 140 -f- .60 126 



.60 28 .40 42 

 Jan. 14 to 21 + 1.10 68 + .65 46 



2.60 100 2.70 122 



Jan. 21 to 28 + .80 102 + .50 42 



.60 66 i.oo 126 

 Jan. 28 to Feb. 4 +2.25 20 -f- . . . 



4.00 148 3-55 1 68 



Feb. 4 to 1 1 + . . . 



4.30 168 4.80 168 



Feb. ii to 18 + .50 56 + .20 32 



2.2O 112 2.10 136 



Feb. 18 to 25 + .50 36 + .20 14 



1.50 132 3-00 154 



Feb. 25 to Mch. 4 + 1.50 88 +1.20 76 



1.20 80 1.50 92 



Mch. 4 to ii +1.80 102 +1.20 108 



1.70 56 1.65 60 



Mch. ii to 18 +2.40 149 -f 1.40 145 



.30 19 .20 23 

 Mch. 18 to 25 +3.60 154 +2.70 149 



.10 14 .20 19 

 Mch. 25 to April i +7.56 162 +2.65 141 



.10 6 .25 27 

 April i to 8 4.70 168 3.41 168 



STIMULATION AND ACCOMMODATION. 



There yet remains to be considered the stimulative reac- 

 tions and accommodations of the plant under changes in the en- 

 vironmental forces which act upon it. Generally speaking, it 

 may be said that sudden changes in the intensity with which a 

 force acts upon a plant results in stimulation, and that gradual 

 alterations are followed by accommodations, and that such ad- 

 justments or adaptations may be produced by the long-continued 

 uniform action of any external factor. 



A striking example of stimulation followed by accommoda- 

 tion is offered by the sensitive plant, and the well-known re- 

 sponse of this plant to a touch or blow consists in folding move- 

 ments of its leaves and leaflets. In repeating the test of it, per- 

 haps this blow may be given by a drop of falling water, or by a 



