Nutrition Investigations. 285 



in experiments with B. coli communis, on culture media containing 

 different kinds of comminuted seaweed, found a slight gas production 

 in one culture, in media with agar-agar and Irish moss. 



GALACTANASES IN THE ANIMAL KINGDOM. 



The only discovered instance of a galactanase in lower animals is 

 cited by Bierry and Giaja (173), who found that the hepato-pan- 

 creatic juice of Helix pomatia produced galactose from extracts of 

 carob seeds (Ceratonia siliqua) ; later experiments upon agar-agar, 

 with extracts from a number of crustaceans {Astacus fluviatilis 

 Rondel., Homarus vulgaris Bel., Maja squinado Rondel., Carcinus 

 moenas L., and Platycarcinus pagarus L.) were entirely negative; the 

 galactans of luzerne and f enugrec were attacked with difficulty by the 

 extract from Astacus. Strauss (221) could find no enzyme attack- 

 ing agar-agar, in the larvae and puppae of various species of Lepidop- 

 tera and Dlptera. 



No galactanases have been found in higher animals. Bierry and 

 Giaja (173), using extracts of luzerne seeds, got negative results 

 with digestive juices of dogs and rabbits , and Sawamura (207) ob- 

 tained similar results with extracts of different sections of the alimen- 

 tary canal of swine and horses. Saiki (205) found saliva, pancreatic, 

 and intestinal juices unable to hydrolyze Irish moss. 



DIGESTION AND UTILIZATION OF GALACTAN BY ANIMALS AND MAN. 



The first study of the digestibility of galactans in higher animals 

 was made in 1903, by Lindsey (191). Alsike clover-seed, containing 

 8 per cent galactan, was fed in connection with hay, the digestibility 

 of which had been previously determined; from analyses of food and 

 faeces, the galactan in the hay (1.72 per cent) was found to be 75 per 

 cent digestible, and that in the clover 95.78 per cent digestible. 

 Saiki (205) fed agar-agar and Irish moss to dogs and recovered a large 

 part in the faeces, as shown by the increased amount of carbohydrate 

 excreted. Lohrisch (194) fed dogs and rabbits agar-agar in its usual 

 form, and also " soluble-agar " prepared from ordinary agar by Dr. 

 Karl Dieterich of Dresden, Director of the Helfenberg Chemical Fac- 

 tory. This product seems to be partially hydrolyzed in its prepara- 

 tion, since it is not only readily soluble in water, but has slight reduc- 

 ing action; it yields on boiling with Fehling's solution, 3.5-4.1 per 

 cent sugar, and if a watery solution is allowed to stand 18 hours at 



