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: (1) dry seeds were put into concentrated H,SO, 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 
CaCO, and distilled water; (2) seed coats were also removed with 
seed nippers; (3) in other experiments only the end of the coat 
was cutaway. ‘The sterile seeds were put into sterile wide mouthed 
bottles, Petri dishes, or flasks for germination. ‘Those cultures 
TABLE IV 
EFFECT OF mace AGENTS ON CATALASE ACTIVITY OF SEEDS, TREATED 
2 MINUTES (40 SEED COATS REMOVED) 
OXYGEN IN CC. LIBERATED DURING 
STERILIZING AGENTS 
i min. 5 min. 19 min. 
Wat o Coal 2 Re ei ere 9.0 20.0 24.3 
Water CHECK) AG iets css 8.9 19.0 24.0 
Fo ® per Cent... 8.5 21.0 24.8 
Fo Sper cont... -.. 8.8 ar.2 24.4 
AgNO, 2 per cent... .....3:. 3.0 6.0 8.0 
AgNO, 2 per cent. oc coe. a3 6.4 8.1 
Peel, t POP OIE os cs es 4.0 11.2 13.0 
HgCl, 1 per cent 4.1 10,0 11.8 
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. 
