GERMINATION THE SEED WAKES UP 47 



which is often as necessary as proving that it will occur with certain 

 others. 



Heat Energy and Carbon Dioxide Set Free. It has been stated 

 in Chapter II that all living things breathe. This means that they 

 take in oxygen, which oxidizes their tissues, produces energy, and 

 liberates carbon dioxide as a waste product. We readily realize this 

 in the case of animals but with plants it needs experimental proof. 



Provide two large-mouthed bottles each with some moist moss, 

 a vial of lime water, and a stopper through which is inserted an 

 accurate thermometer. In one of them put a handful of soaked 

 seeds and leave the other with none. 



As the seeds begin to grow it will be observed that the thermom- 

 eter in that bottle stands higher than in the one with no seeds, also 

 that the lime water in the seed bottle is much more milky, which 

 proves the presence of more carbon dioxide. The lime water in 

 the seedless bottle is slightly milky due to the carbon dioxide 

 present in the air. Without this check experiment, nothing could 

 be proved, as the rise of temperature could not be compared 

 and the presence of the carbon dioxide could be attributed to that 

 known to be in the air. Moss was put in both bottles so that all 

 conditions should be the same ; if this had not been done, it might 

 have been objected that the presence of the wet moss affected 

 the temperature or gave off carbon dioxide. 



While plants do not breathe as actively as animals, still it is 

 thus proved that they do breathe in the same way and for the 

 same purpose, namely, to liberate energy for life. The fact that 

 they are less active and need less energy accounts for less evidence 

 of their breathing. 



SUMMARY 



The seed, a stage of rest, not stoppage of life. 

 Value of this resting stage: 



Dispersal 1 g toward reproduction. 



Protection over winter J 



Germination (resumption of active growth). 

 Conditions for germination: 



Moisture Air supply, why necessary experimental evidence. 

 Heat Stored food 



