FUNCTION OF THE NITROGENOUS MATTER OF SEEDS. 43 



The most remarkable thing in this clevelopement is the 

 part performed by the nitrogenous matter of the seed, 

 which becomes a constituent element of the root-fibres, 

 stems, and leaves, where its agency serves to bring about 

 the formation of cells. After the death of the first 

 leaves, it becomes a constituent of the new ones, per- 

 forming in them the same part over again, so long as 

 there remains material for cell-formation. But the nitro- 

 genous matter itself is not in reahty worked up in the 

 plant, and forms no actual tissue or component part of 

 the cell. 



The experiments of Boussingault on the growth of 

 plants, in the absence of all nitrogenous food ('Annal. de 

 Chim. et de Phys.,' ser. iii., xliii., p. 149), though under- 

 taken for a different purpose, are well adapted to remove 

 all doubt about the very important power possessed by 

 the nitrogenous matter just now alluded to, viz. of main- 

 taining the vital process in the plant, even where the 

 mass of the plant itself receives no increase. 



In these experiments lupines, beans, oats, wheat, and 

 cresses were sown in pure pumice-stone dust, washed 

 and burnt, with which was mixed a certain quantity of 

 ash from stable-manure and from seeds similar to those 

 sown. The plants were grown partly under glass bells, 

 with a constantly-renewed supply of air containing 

 carbonic acid. The air supplied, and the water used 

 for the plants, were most carefully freed from ammonia. 

 The results of these experiments were as follows : — 

 In an experiment wliere the plants were grown under a 

 glass bell, 4*780 grammes of seeds (lupines, beans, and 

 cresses), containing 0-227 gramme of nitrogen, gave 

 16-6 grammes of dried plants; adding the amount of 

 nitrogen in the soil, 0-224 gramme of that element was 

 recovered. In another experiment, where the plants 



