222 PHYSIOLOGY [Bot. Absts., Vol. IV, 



and cultivation of Gonococcus: veal broth, neutral to phenolphthalein, agar, salt, peptone 

 and 10 per cent human blood which had been heated to 56 °C. for 30 minutes; the culture tubes 

 were stoppered air-tight* Salt could be omitted; the addition of glycerol or dextrose or the 

 omission of peptone seemed to be unfavorable. — Selman A. Waksman. 



1471. Rupp, E., and F. Lbhmann. Zur Titration von Zuckerarten. [Titration of sugars.] 

 Zeitschr. Untersuch. Nahrungs-u. Genussmittel 37: 162-164. 1919. 



1472. Scales, F. M. The cuprous chloride-iodine method for reducing sugars simplified. 

 Jour. Indust. Eng. Chem. 11: 747-750. 1919. — A method applicable for any reducing sugar 

 is described for the determination of reduced copper by iodimetry in a modified Benedict's 

 solution. — Henry Schmitz. 



1473. Sperlich, Adolf. Jod,ein brauchbares mikrochemisches Reagens fur Gerbstoffe, 

 insbesondere zur Darstellung des Zusammenhanges in der Verteilung von Gerbstoff und Starke 

 in pflanzlichen Geweben. [Iodine, a useful micro-chemical reagent for tannins, especially 

 for proving the relation in the distribution of tannin and starch in plant tissues.] Sitzungsber. 

 K. Akad. Wiss. Wien. (Math.-Xat, Kl.) 126: 103-153. 1 pi. 1917— Free idoine, in traces, 

 can penetrate the living plasma of the plant cell without harming it, and causes the tannins 

 in solution in the cell sap to form firm and characteristic bodies of brownish color. These are 

 apparently oxidation products belonging near or in the phlobaphene group. The greatest 

 advantage in the use of this reagent lies in the simultaneous and definitely contrasted presen- 

 tation of the starch and tannin under the microscope. Investigations with members of var- 

 ious groups of the flowering plants showed that in plants where both starch and tannins are 

 present, they are not as a rule present in the same cell, and often the secretion and disorganiza- 

 tion of the two substances run parallel. In tissues or tissue zones homogeneous as to content, 

 one of the substances makes way for the other in the course of development. The opinion 

 that all tannins are insignificant excretions, or perhaps protective excretions, should be 

 discarded. — V. C. Dunlap. 



1474. Steenbock, H. White corn vs. yellow corn, and a probable relation between the fat- 

 soluble vitamine and yellow plant pigments. Science 50: 352-353. 1919. — Two years ago the 

 writer experienced some difficulty in getting rats to rear their young on a ration which, to a 

 considerable extent, consisted of corn. During the course of the past year a considerable 

 amount of work dealing with the occurrence of the fat-soluble vitamine in roots was completed. 

 It was indicated that colored roots such as carrots and sweet potatoes are rich in fat-soluble 

 vitamines, while sugar beets, mangels, dasheens, and Irish potatoes contain little or none of 

 it. It was then recalled that when the difficulty with female rats to rear their young had been 

 observed it had been impossible to obtain sound yellow corn, and white corn had been used. 

 It has now been demonstrated with eight different varieties of corn grown in the middle west, 

 that while white corn contains no demonstrable amounts of fat-soluble vitamine, yellow corn 

 may contain sufficient amounts to allow normal growth and reproduction in the rat. These 

 relations suggested the possibility of correlating other instances of the simultaneous occur- 

 rence of fat-soluble vitamine and yellow plant pigments, such as oleo oils and butter fat. 

 From evidence it appears reasonably safe, at least as a working hypothesis, to assume that 

 the fat-soluble vitamine is a yellow plant pigment, or a closely related compound. — A. H. 

 Chivers. 



1475. Steenbock, H., axd E. G. Gross. Fat-soluble vitamine. II. The fat-soluble 

 vitamine content of roots, together with some observations on their water-soluble vitamine 

 content. Jour. Biol. Chem. 40: 501-531. PL 1. 1919.— The fat-soluble content is high in 

 carrots and yellow sweet potatoes as compared with red beets, parsnips, rutabagas, sugar beets, 

 potatoes, mangels, and dasheens. Absolute comparisons of the amounts of the vitamine 

 found in different plant materials are impossible until we know something of its association 

 with specific principles or physiological processes in plants. — G. B. Rigg. 



