14 HORTICULTURAL SOCIETY OF N 



HERBACEOUS GROUNDS, 



y. Total Number of 



^^^ Exposure Hours 



Dec. 17 to 24, 1900 + 1.50 74 



—2.25 94 



Dec. 24 to 31 +1.50 90 



— .85 78 

 Dec. 31 to Jan. 7, 1901 + .80 68 



— 2.10 100 



Jan. 7 to 14 + .80 140 



— .60 28 

 Jan. 14 to 21 + 1.10 68 



— ^2.60 100 



Jan. 21 to 28 + .80 102 



— .60 66 

 Jan. 28 to Feb. 4 +2.25 20 



— 4.00 148 



Feb. 4 to 1 1 + . . . 



—4.30 —168 



Feb. II to 18 + .50 — 56 



— 2.20 — 112 



Feb. 18 to 25 + .50 36 



—1.50 —132 



Feb. 25 to Mch. 4 + 1.50 88 



— 1.20 — 80 



Mch. 4 to II +1.80 102 



—1.70 — 56 



Mch. II to 18 +2.40 149 



— .30 — 19 

 Mch. 18 to 25 +3.60 154 



— .10 14 

 Mch. 25 to April i +7-56 162 



— .10 — 6 

 April I to 8 4.70 168 



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 



