igoS] 



CLAPP—STUDY OF TRANSPIRATION 



265 



EXPLANATION OF GRAPHS 



D= dryness 



T= temperature 



.p, , L=light Tr= transpiration— 



fifih- V- \t"^s given for T should be read in the seventh x-ertical space from the base ?me; D in the 



Wlh, L in the third; and Tr in the first. 



1. Zea Mays, May 7-12. T ic^is; D 30-35; L 20-30; Tr o-r. 



2. Lyco^ersicum escideuttim. May T3-18. T 15-20; D 30-35; L 20-30; Tro-i. 

 Salvia hxvolucrata. May 20-25. T 10-15; ^ 35-4^; L 20-30; Tr 0^1. 

 Seneclo Petasitis. May 28— June 2. T 10-15; D 35-40; L 20-30; Tr 0-2. 



S- Cestrum elegans, June 3-8. T 20-25; D 35-40; L 20-30; Tr o-J. 

 o. I pomoea purpurea. June 1(^15. T ro-15; D 30-35; L 20-30; Tr o-J. 

 Euphorbia pulcherrima. Oct. 22-27. T 20-25; D 30-35; L 20-30; Tro-i. 



3- 



4- 



7 



Nov. 3. T 15-20; D 40-45; L 20-30; Tr o-i. 

 T 20-25; ^ 40-45; L 10-15; Tr o~i. 

 Nov. 12-17. T 20-25; 1^40-45; L 10-15; Tro-i 



^^t'nus commums. JNov. 12-17. ^ 20-25; -L) 40-45; 1. 10-15; Aro-i. 

 6w/27^;; Striatum, Nov. 19-24, T 15-20; D 30-35; L 10-15; Tr o-J. 

 f liotr opium per uviariiun. Nov. 26-31. T 20-25; D 40-45; L 10-15; Tr 



tUP.m.r-in Kriffllr,*^ T\ — A. , -- t* --. t~^ -_ -_.. T --« »-. T"^ «_t 



8. Phaseolus vulgaris, Oct. 29 

 9- Impatiens Holstii. Nov. 5-10. 



10. Ricinus communis. 



11. .4 



12. Heliotroptumperuz.^ ._.. _ ^.. . _ .^, ^ ^. ,^, ^, 



13- Ctnerarta stellaia. Dec. 6-12. T 20-25; D 50-55; L 10-15; Tr o-i. 



14- Primula sinensis, Dec. 13-19. T 20-25; 040^45; L 10-15; Tr o-J. 



^5- ^^^rysanthemum Jrutescens. Jan. 14-19. T 10-15; I^ So-55; L 10-15; Tro-2. 

 16. Pelargonium zo7iale. Jan. 21-26. T 30-35; D 40-45; L 10-15; Tro-2. 

 17- Fuchsia speciosa. Jan. 28— Feb. 2. T c^5; D 40-45; L 10-15; Tr o-x. 

 15. Tropaeolum ntajus. Feb. 4-9. T 10-15; D 45-50; L 10-15; Trc^i. 

 19- Pelargonium domesticum. Feb. 11-16. T0-5; 030-35; L 10-15; Tr 0-1. 



20. Cokus Bluffiei var. Feb. 18-23. T 50-55; D 20-25; L 20-30; Tr o-i. 



21. Ftcus elastica, Feb. 25— Mar, 2. T 15-20; D 55-60; L 20-30; Tr o-J. 

 Pelargonium peltaium. Mar. 4-9. T 20-25; I^5o-SS; L 20-30; Tr o-r. 



23- Vtcia Faba. Mar. 11-20. T 15-20; D 40-45; L 20-30; Tr o-J. 



24. Senecio mikanioides. Mar. 18-23. T 20-25; ^ 30-3S; L ro-15; Tr o-i. 



25 I^elianthus annuus. Mar. 25-30. T 25-30; D 35-40; L 20-30; Tr 0-2. 



20. Lupinus albus, Apr. 1-6. T 10-15; ^ 4o-45; ^ 20-30; Tr c^i- 



. T. . .-. T ^; Tro-i 



L 20-30; 

 DL20-J, 

 T i5-2o;''D 3(^35; L 20-30; tr o- 



27. Hedera Helix. Apr. 8-13. T 15-20; D 40-45; L 20-30; Tro-J. 



28. Tradescantia zebrina, Apr. 15-20. T 30-35; D 40-45; L 20-30; Tr o-J. 



29. Begonia argentea giUtata. Apr. 22-27. "T 30-35; 15-20; DL 20-30; Tr o-}. 



19 — May 



Briefly they bring out these facts: there are two daily extremes, a 

 maximum loss around noon when the sunh'ght is most intense,, heat 

 usually the greatest, moisture least in the atmosphere, but a good sup- 



around 



occurs 



some time during the night when the temperature is low, the atmos- 

 pheric moisture approaches saturation, the darkness is complete, and 

 m most plants the stomata are closed. The 

 morning sometimes suddenly drops or rises. This is due either to the 



cur\' 



