66 BOTANICAL GAZETTE [JANUARY 
uppers used but 0.4406 cc., a ratio of 2.28:1. A repetition of 
this experiment resulted in the lowers using 1.257 cc. in 22 hours, 
the uppers 0.772 cc., a ratio of 1.63:1. Invisible defects in coats 
might cause some variation in these ratios, but they are believed 
to approximate average results. 
It is interesting to note that two lowers in atmosphere used 
2.687 cc. of oxygen in 42.3 hours, while the same number used 
1.007 cc. in 12.5 hours in 96 per cent oxygen; and that uppers 
which used 0.509 cc. in 42.3 hours used 0.4406 cc. in 12.5 hours 
in 96 per cent oxygen. The increased oxygen pressure causes a 
large increase in the oxygen intake of both seeds with coats intact, 
but exerts the greater influence on the lowers. The relation 
between oxygen influence and respiration seems to be close. At 
least we may say that the conditions of the oxygen supply which 
lead to increased use of oxygen are just the conditions which bring 
about germination. The possibility that oxygen exerts its stimu- 
lative effect on germination by increasing respiration, thereby 
yielding more energy, is strongly suggested, without, however, 
precluding the possibility that other effects correlated with increased 
respiration might determine its influence in germination. 
BECKER’ recently tested-the influence of oxygen on the germi- 
nation of seeds of several plants. The fruits of Dimorphotheca 
pluvialis were found to germinate more readily in O, than in air, 
the ray seeds especially showing the favorable influence. Short 
exposures to oxygen (15 hours) had no such effect, but if the time 
of exposure were lengthened to 30 hours, this exposure favored 
further germination under atmospheric conditions. The ray seeds 
again showed the effect more strongly than the disk seeds. When 
the fruit and seed coats were removed, 10 hours’ exposure to 
oxygen affected germination favorably, but 13 hours’ lengthened 
the germination time. The seeds of Calendula eriocarpa with coats 
intact were greatly favored by oxygen, while the yellow-brown 
vertical fruits of Atriplex hortensis and A. nitens showed an injurious 
effect from increased oxygen pressures. The relation of oxygen to 
germination in these cases seems to be irregular and inconstant. 
Becker, H., Uber die Keimung verschiedenartiger Friichte und Samen bei 
derselben Species. Beih. Bot. Centralbl. 29':21-143. 1912. 
