62 MINNESOTA BOTANICAL STUDIES. 



were dead. The leaves had assumed a dirty brown color. The 

 center of the shoot was badly discolored. The appearance of 

 the plants was ver}^ similar to that of a frozen plant. 

 The plants which were subjected to 1/15000 part of the reagents 

 were badly effected, the outer leaves were dark brown but the 

 center was not affected. The plants grew but remained weak 

 and straggling throughout the time the experiments were run- 

 ning. The action of the two reagents seemed to be the same, 

 little or no difference could be detected. 



The plants which were kept in an atmosphere containing 

 1/40000 part of the reagents did not appear to be visibly affected 

 when taken from the bell jars. The subsequent influence of the 

 reagents was, however, very marked, especially on the plants 

 in the chloroform experiment. Compared with the control 

 plants at the end of the experiment, February 10, with which 

 they were equal at the start, they showed a great advance. 



4. The Influences of Gases and Vapors upon Resting 



Bulbs. 



The bulbs used in these experiments were ArtscBma triphyl- 

 him. Narcissus, Hyacinth, Croats, and Freesia. The reagents 

 used were oxygen, nitrous oxide, ether, chloroform, carbon bi- 

 sulphide, ammonia and alcohol. These experiments were started 

 in November and December, months in which bulbs of this kind 

 are very hard to start, since they require a certain period of rest 

 before beginning growth and this period generally extends 

 through the months of October, November and December. 



The bulbs were kept under bell jars and the reagents which 

 were in a liquid form were introduced in aqueous solution. 

 Where gases were used in the experiments they were intro- 

 duced by displacement. 



A. Gases. — Narcissus bulbs were placed under bell jars con- 

 taining oxygen in the following proportion: 20 per cent., 50 

 per cent, and 100 per cent. The capacity of the bell jars was 

 4000 cc. 



