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BRIEFER ARTICLES 



337 



of their width. Truncated crystals are common, especially those in 

 which one side is about half as long as the opposite side. 



Among the naked crystals are others which are furnished with an 

 envelope (fig. i, a, b, g); the whole then resembles an aleurone grain. 

 The inclosed crystals may resemble any of the free forms, but are usually 

 complete hexagonal crystals. They may also be of various sizes, but 

 are usually about the size of the natural aleurone grain. Rarely more 

 than one enters into the composition of a single grain (fig. i, h), as 

 happens also in some kinds of 

 natural grains. 







a 



b 



c 



d 



e 



g 



h 



Fig. i. — Artificial aleurone grains: a, 



The envelope varies in thick- 

 ness independently of the size of 

 the crystal. It is usually arranged 

 symmetrically about the latter, but 

 the truncated crystals have a tend- 

 ency to occur at one side. The out- 

 line of the grain is then globular or 



slightly elliptical, but not angular. protein crystal surrounded by an amor- 

 Occasionally the outermost layer phous protein envelope in which is in- 



of the envelope differs from the dudedadropof oil which in size and posi- 



rpcf u • tlon resembles a globoid; b, similar body 



rest in being more opaque and without a n oil drop; c-A, various forms of 



Slightly granular (fig. i, g), when it crystals resembling those which occur in 

 takes the form of a narrow but dis- natural aleurone grains; g, the amor- 

 tinct membrane This resembles phous envelope with a differentiated outer 



the similar structure sometimes Iayer such as ° ccurs . in .? me ***" ? 

 found in natural aleurone grains. 

 In an experiment in which some 

 fatty matter had not been removed 

 by the ether, many extremely small oil droplets came through the filter 

 and were deposited with the artificial grains. A small number of these 

 had been incorporated into the grains, each of which then consisted of 

 a crystal, an oil droplet, and an envelope. The oil droplet thus resembled 

 the globoid of the natural aleurone grain and the whole artificial grain 

 was extremely similar in appearance to the natural one. In view of this 

 it seems very probable that artificial globoids could easily be produced 

 as inclusions in the artificial aleurone grains by causing dissolved 



grains; k, grain containing three crystals, 

 a condition sometimes found in natural 

 grains. 



globoid 



material to precipitate during the formation of the protein crystals. 

 But this did not seem to be sufficiently important to warrant any 

 special effort directed to this end, particularly as globoids do not always 

 accompany the crystals in natural aleurone grains. 



