CHAPTER II. 



DESERVE STUFFS IN SITU ALEURONE GRAINS PROTEIN 

 CRYSTALS FAT OILS MOUNTING OF PERMANENT PRE- 

 PARATIONS. 



PRINCIPAL MATERIALS USED. 

 Ripe Peas. 

 Grains of Wheat. 

 Seeds of Lupinus (Lupin). 

 Seeds of Ricinus conimunis (Castor oil). 

 Sections of the same hardened for twenty-four hours in alcohol. 



PRINCIPAL REAGENTS, ETC., USED. 



Glycerine iodine Alcoholic borax-carmine Millon's reagent Iodine- 

 green, or Methyl-green Magenta Olive oil Glacial acetic acid 

 Eosin Logwood--! per cent, osmic acid Tannin Ferrous sulphate 

 solution Xylol Canada balsam. 



The Pea. Section-Gutting. We first of all study the Pea 

 (Pisum satii'um). A ripe seed is halved by a sharp pocket-knife, 

 and in such a manner that the two fleshy cotyledons are cut 

 .across ; smooth the surface and then take from it a thin cross 

 section with a sharp, hollow-ground razor. On the subject of 

 section -cutting with the razor the following points can be 

 noted : 1. The cut surface should be moistened before cutting 

 the section, usually with water, but in this case with glycerine, 

 since the preparation suffers in water, and we shall observe it in 

 glycerine. 2. The first section is not to be used, as the tissue 

 here would be too much injured by the pocket-knife. 3. In such 

 resistant tissues as that of the pea only very small and exceedingly 

 thin sections ought to be taken, as the edge of the razor would 

 be very easily notched. If the razor has gone too deeply into the 

 tissue, and it is seen that the resistance to its progress increases, 

 it is better to withdraw the razor, rather than force it to the end 

 of its cut. 4. Unless the investigation requires it, it is advisable 

 not to commence the section with the outer surface of the object 



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