DESSICATION IN PLA.NTS. 153 



hour is in most cases moderately active and in 1 hour 

 quite active. The plants contained 14*55% of water, 

 after being kept for 1 day at 45°C. they contained 6*9%, 

 after 2 days 6 '84%, after 3 days 6*76%, and after a 4th day 

 at 50°C. they contained 5*56% of water. On comparing 

 these results with those given in Table D., p. 376, in the 

 Journal of the Linnean Society for 1896 (On Assimilatory 

 Inhibition) it can be seen that there is a certain, though 

 by no means proportional, relation between the loss of 

 water and the inhibition of the power of assimilation. 



Similar experiments with dried seeds show that there 

 is a distinct relation between the loss of water and loss of 

 germinative power. After 2 weeks drying in a dessicator 

 at 20°C. followed by 2 weeks at 37°C. to 38°C, Wheat 

 contained 2'67% of water and 91% of the seeds germinated 

 (percentage before drying was 93%), Lupinus albas con- 

 tained 1*88% of water and 94% of seeds germinated (of 

 normal 95%) Bicinus communis contained - 92% of water 

 and 40% of the seeds were capable of germination (of 

 normal 62%). Zea mais contained 2*5% of water and 88% 

 of seeds germinated (of normal seeds 92%). Similarly 

 with other seeds kept in a dessicator for 2 weeks at 20°C. 

 and then for 6 weeks at 37°C. to 38°C, Zea mais contained 

 1'7% H 2 and 80% of the seeds were capable of germination 

 (normal 92%), Lupinus albus contained 1'28% of water 

 and 92% germinated (normal 95%), Cucurbita pepo con- 

 tained 0'87% of H 2 and 90% germinated (of normal 94%). 

 In the case of Cucurbita seeds the presence of a large 

 external husk forming a large fraction of the weight of 

 the seed forms a disturbing factor. If these were free 

 of all hygroscopic water the actual seed would contain 

 between 1% and 2%. It appears therefore that even with 

 the most resistant of seeds it is impossible to reduce the 

 percentage of water, held by the seed to lower than from 



