STIMULI AND THEIR ACTIONS 



373 



of form-changes are also depressed in narcosis. Growth and cell- 

 division cease. In order to prove the inhibition of growth, Claude 

 Bernard arranged the following experiment (Fig. 166). Two 

 empty, cylindrical flasks were provided, above and below, with 

 openings that were closed by rubber stoppers, each pierced by a 

 glass tube. In each of these flasks there was placed, half-way up, 

 a moist sponge, and upon the latter sprouting plant-seeds were 

 laid. Through the lower opening one flask (') communicated by 

 means of a rubber tube (V) with a glass cylinder (t), which con- 

 tained at its bottom a layer of ether (S) ; through the stopper of 

 the cylinder, beside the tube V, an open glass tube (a) projected 





FIG. 166. Apparatus for the comparison of germinating plant-seeds in the normal condition and 

 in narcosis. (After Claude Bernard.) 



from the outside down to one-half the depth of the cylinder. The 

 lower opening of the other flask (e) communicated through the 

 glass tube (a') directly with the outside air. To the glass tubes 

 that led outside through the stoppers in the necks of the flasks, a 

 forked rubber tube (b) was fastened, which was in connection with 

 an aspiration-apparatus (P). If the water of the water-pipe (R) 

 was let through the aspirator, it sucked the air through the two 

 glass flasks, of which the one received pure air directly from 

 the outside through the tube (a 1 ), while the other took in 

 through the glass cylinder (t) air charged with ether-vapour. 

 In this way a continuous stream of pure air passed through the 

 germinating seeds of the one cylinder and a stream of ether- vapour 



