LIST OF ILLUSTRATIONS. 



FIG. PAGE 



1 Apparatus for demonstrating respiration .... 2 



2 Apparatus for estimating COo produced during respiration . 4 

 3, 4, 5 Winkler-Hempel apparatus for gas-analysis . . . 7, 8 



6 Foil clamp for holding cover-slips together under water, for 



use with Velten's hot-stage 18 



7 Apparatus for the preparation of water free from CO., hut 



not free from oxygen 28 



8 Arrangement for the culture of plants in an atmosphere free 



from CO., 30 



9 Apparatus for gas-analysis for use in experiments on assimi- 



lation 42 



10 Timiriazeff's eudiometer 46 



11, 12 Lemna cultivated in various nutrient solutions . . 64, 65 



13 Apparatus for demonstrating root pressure .... 75 



14 Another apparatus for the same purpose .... 77 



15 The potometer, for estimating the absorption of water by a 



cut branch 80 



16 A modification of Kohl's apparatus for the same purpose . 88 



17 A method of preventing evaporation from the surface of a 



flower-pot 97 



18 Apparatus for comparing loss by transpiration with the water 



absorbed . . • 99 



19 A spring-balance for use in transpiration experiments . 101 



20 A hygrometer made of the awn of Stipa for performing 



Garreau's experiment 103 



21 Devaux's gelatine method of making an air-tight junction 



with the j)etiole of a leaf 108 



