128 GERMINATION. 



Edwards and Collin, thit the oxygen which the plant uses, 

 does not all come from the air, but that the embryo possesses 

 the power of decomposing water, and using the oxygen and 

 hydrogen for different operations in developing tlie plant. — 

 It would seem, however, that a small quantify of oxygen was 

 necessary to produce a commencement of the vital action, to 

 give the first,impulse to vitality. By numerous experiments, 

 it has been proved, that the best proportion of oxygen with 

 other gases is as one to four, the very ratio found in nature 

 in the constitution of the atmosphere. 



163. Heat is another necessary condition, on which germij 

 nation depends. Germination cannot take place in a temper- 

 ature, uniess some degrees above freezing, and it may take 

 place in a temperature, which would be entirely inadequate to 

 the perfection of its growth. If the temperature is too high, 

 the seeds ma\' germinate, but unhealthy action 's produced, 

 and the plant perishes by over action, produced by this pow- 

 erful agent. 



164. It has been found that Wheat, Barley and Rye, would 

 germinate at 44 degrees Fahr. which is about the lowest point 

 it v.'ould take place. These grains being comjiosed in a great 

 degree of starch, and at the expense of which germination 

 probably proceeds, it was thought that these seeds would sus- 

 tain any temperature as high as starch \\ould, without burst- 

 ing its integuments. Under ordinary circumstances this 

 takes place at a little above 167°, but this temperature was 

 found sufficient to destroy the vitality of the various grains, 

 Beans, Peas, and like seeds. Many lost their vitality at 125^ 

 and some as low as 113°, temperatures which the surface of 

 our soil often exceeds. These facts teach us the necessity of 

 shading, or of planting our flowers and delicate garden seeds 

 in cool places, when it is done after the warm days of our 

 spring come on. V/e vainly endeavored for two or three 

 years to obtain plants from various seeds, by the utmost care 

 in preparation of the soil, and in planting, but the seeds would 

 not germinate. We then sowed them in boxes in the shade, 

 and they germinated readily, and by transplanting accom- 

 plished our desires Much of the vituperation against seed, 

 men would be saved by a similar course. Many of our com- 

 mon garden seeds require similar treatment. 



165. When the three agents above noticed, are brought to 

 act upon the seed in due proportion, it begins to swell, bursts 

 its integuments generally by the protrusion of a radicle; 

 which takes its direction downwards, and soon after the plu- 

 mula or stem makes its appearance and takes its course up- 



