724 GRAMINE.E. 



cells of very small size ; this proper coat of the fruit in the furrow is 

 of rather spongy appearance. 



In some varieties of barley the fruit is constituted of the above 

 tissues alone and the shell, but in most the palese are likewise present. 

 They consist chiefly of long fibrous, thick-walled cells, two or four rows 

 deep, constituting a very hard layer. On tranverse section, this layer 

 forms a coherent envelope about 35 mkm. thick ; its cells when exa- 

 mined in longitudinal section show but a small lumen of peculiar undu- 

 lated outline from secondary deposits. 



The gluten-cells varying considerably in the different cereal grains, 

 afford characters enough to distinguish them with certainty. In wheat, 

 for instance, the gluten-cells are in a single row, in rice they form a 

 double or single rov/, but its cells are transversely lengthened. 



The inner tissue of the albumen in barley is filled up with large 

 irregularly lenticular, and with extremely small, globular starch granules, 

 the first being 20 to 35 mkm., the latter 1, 2 to 3 mkm. in diameter, 

 with no considerable number of intermediate size. The concentric layers 

 constituting the large granules may be made conspicuous by moistening 

 with chromic acid. 



The layer alluded to as being composed oi gluten-cells is loaded with, 

 extremely small granules of albuminous matters (gluten), which on 

 addition of iodine are coloured intensely yellow. These granules, which, 

 considering barley as an article of food, are of prominent value, are 

 not confined to the gluten-cells, but the neighbouring starch-cells also 

 contain a small amount of them : and in the narrow zone of denser 

 tissue projecting from the furrow into the albumen, protein principles 

 are equally deposited, as shown by the yellow coloration which iodine 

 produces. 



The gluten-cells, the membrane embroynnaire of Mege-Mourifes, con- 

 tain also, according to the researches on bread ^ made by this chemist 

 (1856), Cerealin, an albuminous principle soluble in water, which causes 

 the transformation of starch into dextrin, sugar, and lactic acid. In the 

 husks (epiderme, ejncarpe and endocarpe) of wheat, Mege-Mouri^s found 

 some volatile oil and a yellow extractive matter, to which, together with 

 the cerealin, is due the acidity of bread made with the flour containing 

 the bran. 



Chemical Composition — Barley has been submitted to careful 

 analyses by many chemists, more especially by Lermer.^ The grains 

 contain usually 13 to 15 per cent, of water; after drying, they yield to 

 ether 3 per cent, of fat oil, with insignificant proportions of tannic and 

 bitter principles, residing chiefly in the husks. Lermer further found in 

 the whole grains, 63 per cent, of starch, 7 of cellulose, 6*6 of dextrin, 

 2"5 of nitrogen, a small amount of lactic acid, and 24 of ash. 



The analysis of Poggiale (1856) gave nearly the same composition, 

 namely, water 15, oil 2"4', starch 60, cellulose 8*8, albuminous principles 

 10-7, ash 2-6. 



The protein, or albuminous matter consists of different principles, 

 chiefly insoluble in cold water. The soluble portion is partly coagulated 

 on boiling, partly retained in solution : 2-5 per cent, of nitrogen, as 



^ He actually examined wAea^, not barley; ^ wrj^tstein, Vierteljahremchr. filr prakt. 



we assume the chemical constitution of the Pharm. xii. (1863) 4-23. 

 two grains to be similar. 



