46 EVOLUTION AND GROWTH. 



THIRD EXPERIMENT. 



GROWTH OF WHEAT. 



Forty-six wheat corns were sown in burnt sand at the beginning 

 of the month of August. At the end of September, the stalks were 

 from fourteen to fifteen inches in height. The greater number of 

 the lower leaves were yellow. The roots were of very considerable 

 length, and formed a kind of mat, which made it difficult to wash 

 and free them from sand. 



RESULTS OF THE ANALYSIS. 



Seeds. Crop. 



Carbon 46.6 48.2 



Hydrogen 5.8 5.8 



Azote 3.45 2.0 



Oxygen 44.15 44.0 



100.00 100.0 



RESULTS. 



Grs. Carbon. Hydfo«^en. Oxyg-en. Aiofo 



The seed dried 25.38 containing 11.84 1.46 11.19 0.87 



The seed dried 46.65 " 22.47 2.67 20.57 0.92 



Gainbycultnre 21.27 +10.63 +1.21 +9.38 +0.05 



In the course of three months' growth, therefore, the weight of 

 the seed had, so to speak, doubled ; but the grain azote was scarcely 

 appreciable. Nevertheless, this experiment upon the wheat had 

 been conducted under precisely the same circumstances as that 

 made upon the clover. The two crops grew in the same apparatus ; 

 they were watered with the same water, which they received very 

 nearly in the same quantity ; the seed was even sown in vessels 

 having exactly the same extent of surface, in order that either crop 

 might be exposed to the same chances of error arising from the ac- 

 cidental presence of dust in the atmosphere. 



The plants produced under the circumstances indicated T-ere far 

 from presenting the vigor which they would have shown had they 

 been grown in the open field. After three months of growth, the 

 clover was much less forward than some which had been sown, for 

 comparison, in a manured and gypsumed soil at the same time. The 

 whea* showed the same weakness ; and after the second month, I 

 observed that each new leaf which was developed upward in the 

 stem, caused one of those at the lower part to droop and grow yel- 

 low. The peas, although they reached maturity, had much smaller 

 leaves, and both fewer and smaller seeds than similar plants grown 

 at large. 



It is well known that it is in great part due to the fertility of the 

 soil in which seeds are grown that the health and vigor of young 

 plants must be ascribed. A celebrated agriculturist, Schwartz, as- 

 certained, for example, that young col^worts or cabbage plants ex- 

 hausted in a remarkable manner the soil in which they were raised 

 fpjr transplantation. The good efiects of the first nourishment ob- 



