QITARTERNARY OR AZOTIZED PRINCIPLES. 79 



which accumulates in all the growing organs, at the same time that 

 it is deposited within the entire extent of the canals which the sap 

 traverses. It might, therefore, be supposed that in the latter situa- 

 tion the azotized substance was associated with matters of ternary 

 constitution, so as to form membranes and tissues. But from the 

 various organs of the many species studied, M. Payen succeeded in 

 dissolving out, by means of alkalies, and entirely eliminating the 

 animalized substances, without causing the slightest rent or erosion 

 in the tissues perceptible with the microscope ; whence it may 

 fairly be concluded, that if these substances everywhere and always 

 accompany the young tissues of plants, they still form no integral 

 part of them.* The animalized matter seems consequently to pre- 

 serve a kind of independence with reference to the organs which 

 secrete, which convey, and which contain it ; it preserves a sort of 

 mobility which allows of its displacement. And it was in fact neces- 

 sary that this should be so ; for as the period of maturity approaches 

 we see the azotized substance carried more particularly towards the 

 generative organs, and finally become fixed, as it were, and accumu- 

 lated in the seeds. I have had frequent occasion to satisfy myself 

 that the trefoil, the red beet, the turnip, &c., contain much less 

 azote after ripening their seeds than they did previously ; and all 

 husbandmen know that the straw or refuse of plants that have run 

 to seed, forms very indifferent fodder for cattle. 



The cambium, that peculiar globulo-cellular matter which is con- 

 stantly found accumulated where the vegetable is forming woody 

 tissue, contains, according to MM, Mirbel and Payen, the same 

 azotized principle of an animal nature, in conjunction with ternary 

 substances, whose composition, as we shall presently see, is repre- 

 sented nearly by carbon and water. f As the cellular tissue is 

 evolved at the expense of the cambium, the animalized matters show 

 a tendency to quit the consolidated organ. The departure of these 

 matters at the epoch of the growth of the cells, explains satisfactorily 

 wherefore the interiors of old trees contain but a few thousandths of 

 azote, while all the organs* of recent formation always contain 

 several hundredths. With the assistance of chemical analysis it is 

 possible to follow the appearance and the removal of the azotized 

 matter ; thus in the alburnum and wood it is observed to diminish in 

 quantity from the circumference to the centre ; this diminution ia 

 also observed in the branches, proceeding from their extremities to 

 their point of junction with the trunk. 



* Payen, M6moire sur les d^veloppemens des Vi^g6taux, p. 42. 



t De Mirbel et Payen, Comptes rendus de rAcad6mie des Sciences, t. xvi. p. 98. 



