The Development of Endosferni in Cereals. 115 



the cells of this layer are packed with aleurone grains, they 

 also contain large, well-defined nuclei and a quantity of proto- 

 plasm. The nuclei of the starch-containing cells of the endosperm 

 are partly disorganised and the cells contain very little proto- 

 plasm. The greater respiratory activity of the aleurone layer 

 may be accounted for if it is to be regarded as a resting cambial 

 layer. 



It has also been demonstrated that there is present in the 

 outer layers of the endosperm of wheat, rice and other cereals, a 

 substance the deficiency of which causes polyneuritis in birds 

 and Beri-Beri in man (7). Funk gave to this substance the 

 name vitamine, and supposed it to be contained in cells rich 

 in protein. It is found in the tissue of the embryo of cereals,. 

 as well as in the aleurone layer, but it is deficient in the starchy 

 endosperm. Since vitamines are usually especially associated 

 with growing tissues, it is not surprising to find that in this 

 layer — a resting cambial layer — they should be especially abun- 

 dant, whereas in endosperm cells derived from it, which degen- 

 erate into starchy receptacles, vitamines should be deficient or 

 absent. 



Brown and Morris (8) advanced the view, from their experi- 

 ments, that the amylaceous endosperm of Granineae represented 

 a "dead storehouse of reserve material." This conclusion does 

 not refer to the endosperm as a whole, but only to the amylifer- 

 ous cells, the possibility of the aleurone cells possessing vitality 

 being left open. Haberlandt (9) regarded the aleurone layer as 

 a glandular digestive organ. 



The following table, taken from the report of a committee of 

 the Royal Society of London, indicates that there are vitamines 

 present in the whole grain of the cereals, but the flour which 

 is obtained after milling contains no vitamines, as they are re- 

 moved with the aleurone layer. 



Vitamines in Plants. 



Fat-soluble B tt i. 1 1 ^ 



(Anti Beri-Beri) Antiscorbutic 



+ - 



- 



- 



- 



+ 4- - + + 



Plant. 



F.t-soluble A 

 (Antirachitic) 



Wheat and whole grain 



. 



+ 



of cereals 







White wheat flour - 



- 







Cornflour 



> 







Polished rice 



- 







Malted barley 



- 



+ 



