230 TEANSACTIONS LIVEEPOOL BIOLOGICAL SOCIETY. 



a mixture of pure nitrogen and hydrogen gases both of 

 which are inert. The effect of the absence of oxygen 

 upon the seeds is nil, as is shown by similar experiments 

 performed with solid sodium hydrate instead of sodium. 





Hemp. 



Wheat. 



Barley. 



LinseecL 



Peas. 



3 weeks. 



97 p.c. 



96 p.c. 



92 p.c. 



80 p.c. 



69 p.c. 



5 weeks. 



94 p.c. 



95 p.c. 



84 p.c. 



72 p.c. 



44 p.c. 



These results show that perfectly dry air does not exercise 

 a sufficiently powerful drying effect to completely with- 

 draw from the seed the last traces of water which it 

 contains, owing to the fact that this water, the removal of 

 which seems to very injuriously affect the vitality of the seed 

 being in a state of partial combination (vide infra) is held 

 by the seed with considerable tenacity. The dry air seems 

 to exercise least effect upon the oily Hemp seeds and most 

 upon the albuminous Peas. The greater drying effect 

 which is exercised upon the Linseed as compared with 

 the Hemp is probably owing to the mucilaginous external 

 coat which the latter possesses and the thinness of the 

 entire coat allowing a greater loss of water to take place. 

 The Wheat, containing to commence with less water than 

 the Barley, is less subject to the drying influence of the 

 surrounding dry air. 



From the foregoing experiments the following general 

 conclusions may be drawn. The power which certain 

 seeds have of resisting the action of absolute alcohol is 

 due to : 



(1) The relative impermeability of the seed coat. 



(2) The inherent vitality of the protoplasm of the 



seed and more especially of the embryo. 



This vitality is different in different seeds and in the 

 different parts of the same seed. Thus in the case of 



