LIST OF ILLUSTEATIONS. 



flG. PAGE 



1 Apparatus for demonstrating respiration .... 2 



2 Apparatus for estimating CO^ produced during respiration . 4 



3 Poil clamp for holding cover-slips together under water, for 



use with Velten's hot-stage 13 



4 Apparatus for the preparation of water free from COj but 



not free from oxygen ...... .24 



5 Arrangement for the culture of plants in an atmosphere free 



from COj 25 



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



lation ........... 36 



7, 8, 9 Winkler-Hempel apparatus for gas-analysis ... 38 

 10, 10 A Lemna cultivated in various nutrient solutions . . 56, 58 



11 Apparatus for demonstrating root pressure .... 68 



12 Another apparatus for the same purpose .... 69 



13 The Potometer, for estimating the absorption of water by a 



out branch 73 



14 A modification of Kohl's apparatus for the same purpose . 76 



15 A method of preventing evaporation from the surface of a 



flower-pot 88 



16 Apparatus for comparing loss by transpiration with the water 



absorbed 90 



17 A spring-balance for use in transpiration experiments . . 92 



18 A hygrometer made of the awn of Stipa for performing 



Garreau's experiment 94 



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



with the petiole of a leaf 96 



20 Apparatus for demonstrating the hygroscopic properties of 



the awn of Stipa 103 



