THE BIO-CHEMISTRY OF ANIMALS AND PLANTS 695 



it from the albumins ; it is, however, easily soluble in salt 

 solutions, and gives most of the usual protein tests. It contains 

 i8'5 — 18'8 per cent. N and o*8 — 0*9 per cent. S, and is phos- 

 phorus-free. Its heat-coagulation temperature is at about 90 , 

 much higher than that of the animal globulins. Abderhalden 

 has recently examined its cleavage products. 



Another very well-crystallised globulin of this class is the 

 protein of the Para nut (Bertholletia excclsa), which has been 

 called excelsin by Osborne. It occurs in a crystalline form in 

 the aleurone grains in the endosperm of this fruit, and can 

 be easily obtained as hexagonal crystals in a similar way to 

 that described for edestin, which it resembles in character and 

 composition. Its hydrolytic cleavage products have recently 

 been isolated by Osborne and Clapp. A striking feature is the 

 unusually large proportion of arginine found (16 per cent.). 

 A very similar protein has been obtained by Osborne in a 

 crystallised form from oats, and called by him avenalin. 



The proteins of leguminous plants have been fairly well 

 examined, and must be included in this class. The globulin 

 of beans, which is called phaseolin (discovered by Ritthausen), 

 amounts to about 20 per cent, of the seeds, which contain also 

 about 2 per cent, of a second globulin of a greater solubility 

 called phaselin. They contain less nitrogen and sulphur than 

 edestin and excelsin. The globulin of peas is called legumin. 

 It is not precipitated by sodium chloride or magnesium sulphate 

 on saturation, and gives a rose-red biuret reaction, like peptone. 

 It is also only partially coagulated by heat. The mono-amino- 

 acids of its hydrolytic products have been examined by 

 Abderhalden and Babkin, and these are very similar to those 

 obtained from conglutin, the protein isolated by Ritthausen 

 (and subsequently studied by Osborne) from lupins. The name 

 of conglutin had formerly been given to a series of proteins 

 isolated from almonds, peach kernels, walnuts, etc. Osborne 

 and Campbell showed that these proteins differed from con- 

 glutin, and accepted the name " amandin " originally given by 

 Proust, for the protein of almonds and peaches. The protein 

 of the hazel nut (Corylus) has been called corylin by Osborne 

 and Harris. This differs from the globulin of walnuts (Juglans), 

 which has been termed juglansin by the same observers, in 

 containing more amide-nitrogen, and in being less readily 

 precipitable by ammonium sulphate. For the separation and 



