38 



BOTANICAL GAZETTE 



[JANUARY 



For some experiments the seeds were freed from the probable 

 inhibiting influence of the hard coats by one of the three following 

 treatments: (i) dry seeds were put into concentrated H 2 S0 4 and the 

 rate of penetration followed by testing with congo red; it required 

 24 hours to entirely carbonize the coat; the carbonized coats were 

 rubbed off with filter paper and the seeds rinsed in a suspension of 

 CaC0 3 and distilled water; (2) seed coats were also removed with 

 seed nippers; (3) in other experiments only the end of the coat 

 was cut away. The sterile seeds were put into sterile wide mouthed 

 bottles, Petri dishes, or flasks for germination. Those cultures 



TABLE IV 



Effect of sterilizing agents on catalase activity of seeds, treated 

 2 minutes (40 seed coats removed) 



which required good ventilation were protected against infection 

 by a system of tubes plugged with cotton. The seeds were left on 

 the moist walls of the containers or on moist filter paper, depend- 

 ing upon the conditions of the experiments. In the determination 

 of the effect of solutions as forcing agents, no foreign absorbing 

 material was allowed in the flasks with the seeds. In all other 

 cases, except where mentioned, the seeds were placed on moist 

 filter paper. 



Forcing agents 



The change of the catalase activity and the ability of the seeds 

 to germinate were used as standards to determine whether or not 

 the substance or treatment under examination was a forcing agent 

 for the juniper seed. 



