CARBOHYDRATES 1 53 



saccharides which yield glucose, galactose, and xylose. Partial acid 

 hydrolysis yields a product whose X-ray diffraction pattern resembles 

 cellulose. The main chain of the amyloids of different species is then 

 composed of 1-4 linked glucoses (Kooiman and Kreger, 1957). Enzy- 

 mological experiments with cellulase suggest that xylose and galactose 

 residues are attached as side chains in an undisclosed pattern. The 

 oligosaccharides derived by cellulase hydrolysis of a number of species 

 were the same, but their relative quantities differed (Kooiman, 1957). 



The test for amyloid is a blue coloration of the amyloid solu- 

 tion upon exposure to I2-KI and sodium sulphate (Kooiman, 1960b). 

 Kooiman has tested over 2,500 species and finds certain families 

 which are general amyloid producers. For example, in the Legumino- 

 sae, the sub-family Caesalpinioideae are a particularly rich source of 

 amyloid. However, the positive species belong only to the tribes 

 Cynometreae, Sclerolobieae, and Amherstieae. Numerous genera in 

 these three tribes are amyloid containing. Galactomannan is frequently 

 encountered as a constituent of the endosperm in the tribes Cassieae 

 and Eucaesalpinieae. 



Outside the Leguminosae amyloid was detected in sixteen 

 dicotyledonous famiUes, but no amyloid was found in the twenty-five 

 monocotyledonous families examined. Some noteworthy distribu- 

 tions follow. In the family Acanthaceae, of the ten species known to 

 produce amyloid all are in the tribe Justicieae. All Paeonia species in- 

 vestigated produced amyloid, but thirty other species of the family 

 Ranunculaceae were negative. All of the investigated taxa of the 

 order Primulales (including, according to the system of Engler, only 

 three families: Primulaceae, Myrsinaceae, and Theophrastaceae) were 

 found to produce amyloid. In connection with the latter observation, 

 it seems pertinent to mention that Hutchinson's arrangement of these 

 famihes differs considerably from that of Engler. Hutchinson places 

 the predominantly herbaceous Primulaceae and Plumbaginaceae in 

 the order Primulales and includes the woody Theophrastaceae, Myr- 

 sinaceae, and Aegicerataceae in the order Myrsinales; according to 

 Hutchinson these orders are in different phyletic groups. It is perhaps 

 premature to draw conclusions from the limited data available, but 

 it is difficult to ignore the striking amyloid distribution unless one 

 wants to assume convergence of both morphological and biochemical 

 characteristics. 



Whatever the ultimate disposition of the famihes in question, 

 it appears likely that the carbohydrate chemistry of the groups will 

 play some contributory role, but much additional exploratory work 

 will be necessary before meaningful conclusions can be drawn from 

 the amyloid data. 



