5o8 Transactions of the Canadian Institlte. [Vol. VII. 



Between these vesiculated cells and the absorption tissue of the 

 embryo were large cells loosely bound together. These cells, even 

 under the low power, were very different from the others, containing 

 large, well-separated granules, coloured a bright green. Under the high 

 power these granules appeared round, angular, or often crescent-shaped. 

 In very thin sections they were quite separated from one another and 

 very brilliantly coloured ; in thin sections the nucleus often was not 

 apparent. In thicker sections these granules were seen to be connected, 

 forming a loose kind of meshwork, the spaces between being filled with 

 a finely granular substance, giving a faint but distinct phosphorus 

 reaction. When treated for the iron reaction a very faint violet tinge 

 appears in these cells, but only between the bodies which stain so 

 brightly for phosphorus. 



From this it seems that, with the exception of the rapidly dividing 

 cells such as those of the radicle and plumule, iron is found in the nuclei 

 only of the various cells of the wheat grain. 



Phosphorus is more widely distributed, appearing between the 

 aleuron grains ; in fine grains in the radicle and plumule cells ; in the 

 foam-like mesh work of another type of embryo cell ; in the very distinct 

 large granules just described, and in the nuclei of all these cells. From 

 the various ways in which these different cells stain, and the several 

 methods of phosphorus distribution in them, one may conclude that 

 there are probably several nucleins present. 



Osborne and Campbell"^ extracted wheat germ with petroleum 

 naphtha, ground the residue to a fine flour, extracted this with water, 

 saturated the clear filtrate with sodium chloride, and subjected the re- 

 .sulting precipitate to a vigorous peptic digestion. The nuclein so pre- 

 pared, they conclude, " is not an original constituent of the extract nor 

 of the cells of the embryo, but results through several molecules of 

 nucleic acid with one of Protein." To this nuclein, washed with water 

 and dissolved in dilute potassic hydrate solution, was added hydrochloric 

 acid until a precipitate formed, which readily separated. When this 

 was filtered off a considerable excess of hydrochloric acid was further 

 added to the filtrate, whereupon a precipitate of nucleic acid separated 

 out which became so dense and brittle that it could be ground under 

 water. 



This operation, as described, I repeated, but a small quantity only 

 of nucleic acid was obtained, which, however, did not become brittle 

 under water. As I expected, the ash of this nucleic acid and of the 



