THE RESERVE MATERIALS OF PLANTS. 75 



conditions, no alkaloid being allowed to remain in the seed, 

 Clautriau found that the active principle made its appear- 

 ance in considerable quantity, and chiefly in thegrowingapices. 

 The same thing was noticeable in the development of mor- 

 phine in the poppy (79), where a more gradual formation 

 was detected. Morphine does not show itself at the out- 

 set of the development of the plant, but appears to be 

 preceded by another alkaloid, giving very clear reactions, 

 which does not seem to be identical with any of the nitro- 

 genous principles extracted from opium. 



The conclusion that must be drawn from these investiga- 

 tions is that these alkaloids, and hence probably all such bodies, 

 are not to be regarded as reserve materials, but as bye- 

 products or excreta, appearing coincidently with the active 

 metabolic processes of the growing plant. 



Besides these accumulations of more or less complex 

 organic compounds in the tissues of plants we meet with 

 certain cases where inorganic material is deposited with a 

 view to subsequent utilisation. These are, however, of 

 much less importance and only occur in comparatively few 

 plants. We have the well-known globoids in the aleurone 

 grains of the castor-oil seeds, the seeds of Bertholletia 

 excelsa and several others. From their disposition and 

 fate, and from the fact that they afford a supply of phos- 

 phorus, it is probable that we may include them in this 

 group. In certain cases also the collections of crystals of 

 calcium oxalate gradually disappear from the cells in which 

 they are deposited, and so seem to minister to the needs of 

 the plant for calcium, an element whose function, however, 

 is still practically unknown. 



BIBLIOGRAPHY. 



(60) Thome. Ueber das Verkommen des Amygdalins und des 



Emulsins in den bittern Mandeln. Botanische Zeitung, p. 

 240, 1865. 



(61) PORTES. Recherches sur les amandes ameres. Journal de 



pharmacie et de chimie, t. xxvi., p. 410, 1877. 



(62) PFEFFER. Pflanzenpkysiologie, t. i., p. 307, 1881. 



(63) JOHANSEN. Sur la localisation de l'emulsine dans les aman- 



des. Ann. des. Sc. Nat. Bot., 7 ser., t. vi., p. 118, 1887. 



