CELL-CONTEXTS AND FORMS OF CELLS. 195 



sodium chloride solutions with water heated from 50 to 60 until 

 a slight turbidity forms. Warm the diluted solution until the tur- 

 bidity disappears and then allow it to cool slowly, when well- 

 defined crystals of the protein separate (Fig. 112). Crystals of 

 the globulin (so-called excelsin) of Brazil-nut were obtained by 

 Osborne by simply dialyzing the faintly acid saline solution in 

 running water. Many of the globulins have received distinctive 

 names, as Amandin, found in the almond, peach, plum, and apri- 

 cot ; Avenalin, found in oats ; Castanin, found in European chest- 

 nut ; Conglutin, found in lupines ; Corylin, found in hazel-nut ; 

 Edestin, found in hemp-seed ; Excelsin, found in Brazil-nut ; 

 Glycinin, found in soy-bean ; Juglansin, found in European wal- 

 nut, American black walnut, and butter-nut; Legumin, found in 

 peas and lentils ; Maysin, found in Indian corn or maize ; Phaseolin, 

 found in kidney and lima beans; Tuberin, found in the potato; 

 Vicilin, found in peas, horse-bean, and lentils ; and Vignin, found 

 in cow-pea. Globulins have also been isolated from the seeds of 

 other plants, but to these distinctive names have not yet been 

 given. Among these may be mentioned barley, cocoanut, castor- 

 bean, cotton-seed, flaxseed, mustard-seed, peanut, radish-seed, 

 rape-seed, rye, sesame-seed, sunflower-seed, and squash-seed. 



II. ALBUMINS are distinguished from globulins by the fact 

 that they coagulate on the application of heat ; they are also solu- 

 ble in water, showing neutral or but a slightly acid reaction. Most 

 seeds and probably most plant juices yield proteins which are as 

 well entitled to be placed in the group of albumins as any of 

 those of animal origin. The best characterized vegetable albumins 

 are Legumelin, found in lentils, cow-peas, peas, and soy-beans ; 

 Leucosin, found in barley, rye, and wheat; Phaselin, found in 

 kidney-bean ; and Ricin, found in castor-bean. 



III. Proteins of another well-defined class are known as 

 GLUTELINS, which are characterized by being insoluble in neutral 

 aqueous solutions, saline solutions, and alcohol. The glutenin of 

 wheat is the best representative of this group. 



IV. The alcohol-soluble proteins, known as Prolamins, have 

 been found in corn, oats, sorghum, and wheat. It has recently been 

 proposed to bring this group of proteins in a group by themselves 

 and call them " gliadins," but as this name has been used to 



