92 



SCIENCE 



[N. S. Vol. LII. No. 1334 



WMle it is known that the larvse of these flies are 

 parasitic in their habits, very little is known of 

 their host relations. 



An intensive ornithological survey of a typical 

 square mile of cultivated prairie: Arthur E. 

 Abel. 



'Bird records of the past two winters, 1918-19IS0, 

 in the upper Missouri valley : T. C. Stephens. 



A study of sociality in the phylum Coelenterata: 

 H. J. Wehman and Gertrude Van Waoenen. 



On the parasites of the xmios of the Lake OTcoioji 

 region: Harry M. Kelly. 



The 1919 outbreak of armyworms and variegated 

 cutworms in Iowa: H. E. Jaques. 



The pathology of lethargic enceplialitis : Henrietta 

 Calhoun. 



Descriptive notes concerning the American hold 

 eagle: Ben Hur Wn,soN. 



Some impressio7is obtained from a review of Pro- 

 fessor Nutting's narrative of the Barbados- 

 Antigua expedition : A, C. Trowbrejge. 



Archeology 

 The material for a study of Iowa archeology: 



Charles Keuben Keyes. 

 The Keokuk type of stone ax: Charles Reuben 



Keyes. 



General 

 The oomparastive stability of colors in wallpaper: 



J. M. LiNDLY. 



Iowa Secticm Mathematical Association of America 

 Note on a generalisation of a theorem of Baire: 



E. W. Chittenden. 



A celebrated theorem of Baire states that the 

 neoessary and sufficient condition that a function 

 F(x) defined on a closed set P in space of )i-dimen- 

 sions be the limit of a sequence of continuous func- 

 tions defined on P is that if Q be a perfect subset 

 of P, then F(x) has a point of continuity in every 

 portion, however small, of the set Q. Professor 

 Chittenden calls attention to the fact that a proof 

 of this theorem g:iven by Vall6e-Pouasin can be ex- 

 tended without difficulty to the case of a set P in 

 an abstract space of a type studied by FrSchet. As 

 a special instance, P may be a perfect set in a 

 compact space of infinitely many dimensions. 



Notes on the history of indeterminate equations: 



E. B. McClenon. 



Professor McClenon traces the history of some 

 indeterminate equations found in the writings of 

 Leonardo of Pisa, showing the contributions that 



had been made to their solution by the Hindus and 

 AralM, as well as their further development by 

 later writers, down to modern times. 



A pseudo velocity-resistance graph for low angle 



firing: M. E. Geaber. 



Mayevski's law for air resistance is unsatisfac- 

 tory 'because the discontinuities introduced render 

 numerical integration difficult. Professor Graber 

 presents a smooth curve law for the velocity-resist- 

 ance relation between the velocities of 750 ft./sec. 

 and 1700 ft./sec. and compares it with a psendo 

 velocity-resistance standardization curve. 



What is number? C. W. Wester. 



An attempt to state in a simple way some of the 

 outstanding differences between current definitions 

 of numiber, especially between what may be called 

 the mathematical and the metaphysical definitions ; 

 and to suggest the lines along which a working 

 agreement may 'be reached as to what shall be 

 thought of as number in elementary mathematics. 



The teaching of limits in the high school: J. V. 



McKelvey. 



In this paper Professor McKelvey discusses cer- 

 tain popular misconceptions in regard to limits and 

 outlines a point of view from which a rigorous and 

 usable understanding of this seemingly bewildering 

 subject may be obtained. No plea is made either 

 for or against the teaching of limits in prepara- 

 tory schools. 



The taxonomy of algebraic surfaces: E. P. Baker. 

 The integration of th-e indefinite integral in the 



first course : W. H. Wilson. 

 A problem in summation of series: John P. Eeilly. 

 A geometric construction for the regular 17-gon: 



Linn Smith. James H. Lees, 



Secretan-y 



Des Moines, Ia. 



SCIENCE 



A Weekly Journal devoted to the Advancement of 

 Science, publishing the official notices and pro- 

 ceedings of the AmericEin Association for 

 the Advancement of Science 



Published every Friday by 



THE SCIENCE PRESS 



LANCASTER. PA. GARRISON, N. Y. 



NEW YORK. N. Y. 



Entered ia the post-office at Lancatter, Pa., aa tecond clau matter 



