38 



sufficiently into account to give the experiments im- 



• * 



portant weight for an inquiry into the oxygen require- 

 ment of plant roots. These experiments need not be consid- 

 ered further. There are, however, two previous investiga- 

 tions which must be reviewed in a little more detail. 

 These are the work of Kosaroff and that of Gannon, both 

 of which have been mentioned already. 



The experiments of Kosaroff 1 were incidental 

 to an investigation of the effects of various factors on 

 water absorption by plant roots. Experiments were made 

 in soil with Phaseolus multiflorus and Vicia faba and 

 in water culture with Phaseolus only. For the soil 

 experiments the ordinary clay pot containing the plant 

 was placed in a somewhat larger glass jar and this jar 

 was covered with a split glass cover, the stem of the 

 plant projecting through a hole in the center of the 

 glass cover so that the aerial portion of the plant 

 projected into the atmosphere. The glasStop was then 

 sealed to the glass jar with grafting wax and a similar 

 seal, was made between the glass top and the stem of the 

 plant. The soil, containing the plant roots, was thus 

 enclosed in an air-tight space. The desired gas was now 

 passed through this by means of tubulatures in the glass 



TZ Sinfluss verschiedener Eusseren Pactoren 

 auf die V/asseraufnahrne der Pflanzen, Diss., Leipzig, 64 

 pp. (1897); Bot. Centbl. U3: 13b -144 (1900). 



