LIST OF ILLUSTRATIONS. 



FIG. PAGE 



1 Apparatus for demonstrating respiration .... 2 



2 Apparatus for estimating C0 2 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 2 but 



not free from oxygen 28 



8 Arrangement for the culture of plants in an atmosphere free 



from C0 2 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 . 83 



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 with horn for performing Garreau's 



experiment 103 



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



with the petiole of a leaf 108 



