viii CONTENTS 



Page 



XXV. Reserve sugar in onion bulb 48 



XXVI. Proteids in onion bulb 48 



XXVII. Cause of nocturnal position of leaves 53 



XXVIII. Values of illumination for leaf positions . . .53 



XXIX. Adaptation of grovfing leaves to changed light relations . 54 



XXX. Heliotropio movements of English ivy . . . .55 



XXXI. Oxygen making by plants 57 



XXXII. Starch in Tropmolum leaves 57 



XXXIII. Consumption of starch in Tropceolum leaves . . .58 



XXXIV. Effect of sealing stomata on starch production . . 59 

 XXXV. Effect of darkness on chlorophyll production . . 59 



XXXVI. Transpiration 60 



XXXVII. Side of Ficus elastica leaf which transpires . . .61 



XXXVIII. Relative transpiration of Hydrangea Hortensia and Ficus 



elastica . . 61 



XXXIX. Passage of water from stem to leaf 63 



XL. Rise of water in leaves 63 



XLI. Starch contents of leaves at various seasons . . 63 



XLII. Production of pollen tubes .68 



