66 The Botanical Gazette. [February, 
plants in his.experiments. Now it is in reality impossible to 
secure two branches from different plants (same species), of 
even the same plant, that are in all respects alike as to fune- 
tion and age, and which have been exposed to the same en- 
vironments during life. Toavoid these difficulties I observed 
the following precautions: 
1. Solanum tuberosum leaflets were used. 
2. Leaflets of the same leaf were used thus securing thos 
of the same age, which had been exposed to the same extifg 
nal environments as nearly as possible. | 
3. The conditions of temperature and moisture were the 
same for all leaflets. 
4. Only healthy looking leaflets were used. 
5. Great care was observed in the handling of leaflets so # 
not to bruise them. pi 
- The petiole was cut straight across as near to the mit- 
rib as possible. 
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eaflets, one in the dark, the other in diffuse’ light were e& 
Same experiment. The following are the results: 
1. Time of first exposure of leaflets, 13 hours. 
ee 
Condition Anaesthet. | Wei i | i i 
: ight in mg.’Weight in mg. 
light ot before grt bee . Loss in mg. pe cae 
gat. normal, exposure, exposure. 
aera 
Diffused .. Ether 769 
MESO coc scceeere| HEMEL... cc ccseee 6 
Ditased saviaeibs Normal Seon cavaa: is pri toes He 
Cvcacatepertad IPR scicewieieices ; 
WME oe Normat.55),...: i56 28 5 ta 
The same leaflets wer 
€ agai i having been & 
posed for 6 hours again weighed after having 
