ESTIMATING SUGAR IN BLOOD 205 



Eberlein may afford some aid in solving the puzzle. In 

 the digestive tract of vegetarian animals, as in the proven- 

 tricle of ruminants, besides bacteria there are always great 

 numbers of infusoria of different kinds which have been 

 introduced with the hay and grasses, which increase there 

 tremendously and may possibly be of importance in the nor- 

 mal process of cellulose digestion. We cannot overlook the 

 possibility that these microorganisms may relieve herbiv- 

 orous animals of part of the labor of digestion by trans- 

 forming the cellulose into sugar by means of cytases for their 

 own needs and utilizing it for building up their own corporeal 

 structure; then later on when they die and are in turn 

 digested, the material they have assimilated may indirectly 

 come to be of use to the host animal. The proof of this 

 suggestion is somewhat difficult because thus far the 

 parasites of the stomach of ruminants have apparently never 

 been artificially cultivated, although this should not be very 

 difficult of accomplishment. 38 



BLOOD SUGAR 



In continuation of the study of the passage of the carbo- 

 hydrates through the living organism the next question to 

 be considered is that of the form in which the sugar, when 

 res orbed from the intestine, circulates in the blood. 



Technic of Estimating the Sugar in the Blood. Prog- 

 ress in the problem of blood sugar depends upon our ability 

 to recover the minute amounts of the sugar unchanged from 

 the great quantities of albumenoid blood colloids in which it 

 may be said to be buried. The technic of analysis of 

 haBmic sugar 39 is therefore closely connected with processes 

 of removal of albumin. An important and very welcome 

 improvement in this connection is the method proposed by 



88 R. Eberlein, Zeitschr. f. wissensch. Zool., 49, 233, 1895; A. Scheunert, 

 Berlin, tierarztl. Wochenschr., 1909, No. 45 ; E. Liebetanz, Arch, f . Protistenk., 

 19, 19, 1910; W. Biedermann, Handb. d. vergl. Physiol., 2' pp. 1337-1344, 1911. 



39 Cf. O. Schumann and C. Hegler, Mitt. a. d. Hamburger Staatskrankenan- 

 stalten, 12, 429, 1911 ; cited in Centralbl. f. d. ges. Biol., 1911, No. 1773. 



