October 22, 1920] 



SCIENCE 



393 



and milled rice. The respiration of frosted wheat 

 plants. The respiration of wheat plants infected 

 with stem rust: C. H. Bailey and A. M. Gujae. 



■ The etiology of Um'bernech in fowls: S. D. 

 ■WlLKlNS and E. A. Butcher. Many theories and 

 beliefs are extant relative to the primary causes of 

 limberneek in poultry. Attempts have been made 

 at the Minnesota Station to produce limberneck 

 by the following methods: (1) Dietary treatment. 

 (2) Feeding and injecting B. botulinus and its 

 toxin. (3) Feeding spoiled foods. (4) Feeding 

 salts and brines. (5) Feeding inorganic poisons. 

 .(6) Feeding larvae of certain flies {Lucilia 

 ccssar). (7) Feeding maggots from various 

 sources. Negative results were obtained in all 

 trials except when larvse of Lueilia ccesar were fed. 

 These larvse were obtained from ova deposited on 

 limberneck carcasses. 



The relation of vitamines to the development of 

 sex organs in cocTierels: 8. D. Wilkins and K. A. 

 Ddtcher. White Leghorn cockerels of uniform 

 age and weight were divided into two groups. 

 .Group I. received a diet of polished rice only, 

 ;whUe Group II. received a diet of polished rice, 

 supplemented by 2 grams of green alfalfa, daily. 

 .The testes were found, after 30 days, to have 

 atrophied, in Group I., in s.pite of the fact that 

 some birds had not lost in weight, showing that 

 atrophy of organs is not necessarily accompanied 

 by general inanition. In Group II. the testes were 

 ■found to be practically normal for birds of that 

 age and breed. 



. Effect of vitamine deficiency on various species 

 of animals. I. The production of xerophthalmia in 

 the rabbit: V. E. Nelson and A. E. Lamb. A diet 

 deficient in the fat-soluble vitamine will produce 

 a disease of the eyes of rats which is called xero- 

 phthalmia. This condition has been repeatedly 

 produced in rats, and is said to have occurred in 

 children, but has not been reported in any other 

 species. We have begun a study of the relative 

 requirements of various species for this substance. 

 On a ration deficient in fat-soluble A young raJbbits 

 grew for a few weeks, but at the end of 60 days 

 lost weight and became nearly blind. Butter-fat 

 effected a cure. It is suggested that herbivorous 

 animals may require more of this vitamine than 

 the rat. 



The role of vitamines in the growth of yeast. I. 

 Are vitamines essential? E. I. Fulmer, V. E. Nel- 

 son, F. F. Sherwood. Evidence indicates Water 

 Soluble B is unnecessary for yeast growth. Yeast 



has been growing months in a vitamine free 

 medium at two thirds the rate manifested in wort. 

 Alcoholic extract of alfalfa stimulates growth. 

 Heating the extract with alkali does not destroy 

 this effect. Alcoholic extracted malt gives results 

 like untreated malt. The ammonia content of the 

 medium influences growth. There is an optimum 

 concentration variations from which materially de- 

 crease the crop. One is unwarranted stating this 

 or that substance is indispensable until the best 

 synthetic medium is developed. 



A correction of two previous papers: 1. Bate of 

 recovery from the action of fluorite rays. S. Sen- 

 sitization to heat due to exposure to light of short 

 wave lengths. The graphical representation of hy- 

 drogen ion concentration. Notes concerning formol 

 titration of nitrogen: W. P. Bovie. 



Charles L. Parsons, 



Secretary 

 (To be continued) 



THE SUMMER MEETING OF THE AMER- 

 ICAN MATHEMATICAL SOCIETY 



The twenty-seventh summer meeting and ninth 

 colloquium of the American Mathematical Society 

 were held at the University of Chicago on Septem- 

 ber 7-11. The meeting was preceded on Septem- 

 ber 6 by a meeting of the Mathematical Associa- 

 tion of America and extended over three sessions, 

 lasting until noon on September 8. On the after- 

 noon of that day the colloquium opened. The col- 

 loquium consisted of two courses of five lectures 

 each, on "Dynamical Systems" by Professor G. D. 

 Birbhofif, of Harvard University, and on "Topics 

 from the theory of functions of infinitely many 

 variables" by Professor P. E. Moulton, of the 

 University of Chicago. The attendance at the col- 

 loquium was eighty-eight, exceeding by nearly 

 twenty the previous record for attendance at a 

 colloquium. 



The attendance at the regular sessions of the 

 Society included more than one hundred and twenty 

 persons among whom were nearly one hundred 

 members of the society. One hxmdred and 

 sixteen persons were present at a joint dinner 

 of the society and the association held on the 

 evening of September 7. Excellent accommo- 

 dations had been provided at Hitchcock and 

 Beecher Halls, and at the Quadrangle Club, which 

 was most generously put at the disposal of at- 

 tending members. A resolution expressing to the 

 department of mathematics of the University of 



