Feb. 1, 1866.] 



SCIENCE-GOSSIP. 



35 



end, a small ring, groove, slit, star, or crack, termed 

 the bile or bilum, around which may frequently be 

 noticed faint rings, plications, or folds. The forma- 

 tion of the granule, the structure and uses of its 

 bilum and rings, have been the subject of much dis- 

 pute amongst microscopists. By some it is affirmed 

 that the granule consists of a nucleus and coverings, 

 and that the plications are due to the coverings 

 cropping out. Others are of opinion that it is made up 

 of layers of amylaceous matter surrounding a bilum, 

 and that the outer layers are denser than the inner ; 

 whilst others assert that it is simply a cell filled with 

 amylaceous matter enclosed by a plicated cell-wall . 

 Leuwenboek, the eminent German microscopist, 

 was of opinion that the granules of Starch were cells 

 "having soluble contents, but an insoluble case." 

 This was denied by Payen, Persoy, and Pritzsche, 

 who stated that the granules consisted of concentric 

 laminae superimposed on one another. M. Martin, 

 librarian of the Imperial Polytechnic Institute at 

 A r ienna, and Mr. Busk, a distinguished naval surgeon 

 and microscopist, are of opinion that the Starch 

 granule is " a cell having a cell-wall much larger 

 than the contents of the cell in a dried state, and 

 therefore puckered and plaited as indicated by the 

 lines on the surface." 



Lately, in a paper by Dr. Allman, of Dublin, pub- 

 lished in the Quarterly Journal of Microscopical 

 Science, the doctor agrees with Pritzsche's theory, 

 that the Starch-granule is, in fact, " a series of cells 

 placed within each other." 

 He thus sums up his remarks : — 

 1st. " That the Starch-granule consists of a series 

 of lamella?, in the form of closed hollow cells, in- 

 cluded one within the otber, the most internal 

 inclosing a minute cavity filled with amorphous (?) 

 Starch; that the concentric striae visible on the 

 granule indicate the surface of contact of these 

 lamellae; and that the so-called nucleus of Pritzsche 

 corresponds to the central cavity. 



2nd. " That while the lamellae appear to be all 

 identical in chemical constitution, yet the internal 

 differ from the external in consistency or other con- 

 ditions of integration. 



3rd. " That the order of the position of the lamellae 

 is centripetal. 



4th. "That while the Starch-granule is thus a 

 lamellated vesicle it must be included in the category 

 of the true vegetable cell, from which it differs not 

 only in the absence of a proper nucleus, but in pre- 

 senting no chemical differentiation between mem- 

 brane and contents." 



Wheat {Triticum mdgare).— This starch consists 

 chiefly of large and small grains, with a few of in- 

 termediate size ; those of common wheat range from 

 •0001 to '0009 of an inch. The smaller are nearly 

 globose, the larger rounded and flattened. In a 

 few of the granules a hilum may be observed with 

 faintly-marked concentric rings around it. 



Rice (Oryza saliva). — The granules of rice starch 

 are polygonal and very small, about "00019 of an 

 inch on an average, and the smallest of commercial 

 starches. They do not, however, adhere in groups, 

 as in many other irregular-shaped species. 



Fig. 27. Wheat. Fig. 28. Rice. 



Maize {Zea mays). — Starch from maize has more 

 or less angular or polyhedral granules; with a dis- 

 tinct hilum in the form of a cross or star. The 

 surface is without any visible rings or markings. 

 In size they average from '0005 to '0007 of an inch. 

 They generally adhere in clusters, and present a 

 hexangular face. 



Fig. 29. Maize. 



Fig. 30. Dhoora. 



Dhoora {Sorghum mdgare). — The starch of the 

 sorghum or dhoora bears considerable resemblance 

 to that of Indian corn. The granules are mostly 

 polyhedral as the result of compression. Eadiate 

 markings indicate the position of the hilum. 



Oat {Avena saliva). — This starch consists of com- 

 pressed granules, often polyhedral. They have a 

 tolerably distinct bilum, but are without external 

 markings. The size varies from '0001 to '0010 of an 

 inch. Most starches exhibit some characteristic 

 feature under polarized light, but in this instance 

 scarcely any variation is observable. 



# 



'0 e 



Fig. 31. Oat. 



Fig. 32. Millet. 



Italian Millet (Setaria Italica).— These gra- 

 nules are very similar to those of maize, differing 

 chiefly in then smaller size (fig. 37). Tbey are often 

 agglomerated together in masses, and maize starch 

 may be taken as the type, of which this and the next 

 are varieties. 



Indian Millet (Panicum miUaceum). — The 



