BIOLOGICAL PAPERS. 203 



barley and wheat being 29'' C, and of scarlet runner, Indian corn and 

 squash 33° 0. 



A third requisite is atmospheric air or, more strictly, free oxygen. 

 In order to prove this conclusively, three bottles were used, in each 

 of which moist blotting-paper was placed, and upon this seeds of 

 Phaseolus vulgaris (common bean) and of Zea tnays (Indian corn) 

 that had been soaked for twenty-four hours. In one bottle we placed 

 a perforated rubber stopper through which a glass tube bent once at 

 right angles had been passed. This was attached to an air-pump 

 and as much air as possible exhausted. While this process was go- 

 ing on we hermetically sealed the glass tube by means of an alcohol- 

 lamp flame, leaving the bottle air- tight. In a second bottle seeds of 

 the same kind and condition were placed and the bottle was tightly 

 stoppered, thereby retaining what air there was within, but preventing 

 the admission of more. In a third bottle of like condition we placed 

 soaked seeds of the same kind, but affixed a stopper through which the 

 air could readily pass. The result was that the seeds in the bottle 

 without air never germinated ; some of those in the one containing 

 air, but stoppered tightly, began to sprout, but soon ceased growing. 

 The seeds in the bottle to which air was constantly admitted germina- 

 ted and produced good-sized plants. When the second bottle was 

 opened a very disagreeable odor escaped, showing that the oxygen of 

 the air had been consumed, carbon dioxide and organic gases formed. 

 This oxidation which takes place is proof of chemical changes going 

 on in germinating seeds. 



Another chemical change caused by germination is shown in malt, 

 which is barley which has been sprouted until the radicle protudes 

 and the process then stopped by applying heat. 



But there are other changes that take place in germinating seeds, 

 as seen in the structure of kernels of corn, etc., when sprouting. 



The seed when germinated contains the embryo, which is an axis, 

 one end of which invariably lengthens and grows towards the light, 

 while at the other end cell multiplication takes i3lace — but always in 

 the direction of dark and moist soil. It is remarkable that these 

 tendencies of ascending and descending axes are irreversible, showing 

 that a superhuman creator causes every individual of the vegetable 

 kingdom to develop according to His immutable laws. 



