432 



SCIENCE 



[N. S. Vol. XLI. No. 1055 



polar circle diagram. In translating Pro- 

 fessor Blondel's " Moteurs Synchrone," Mr. 

 Mailloux has rendered a valuable service to 

 English-speaking electrical engineers. 



Ealph E. Lawrence 



Storage Batteries. By Harry W. Morse. 



New York, The Macmillan Company. 1912. 



This little book of 263 pages on storage bat- 

 teries is based upon lectures given by Professor 

 Morse at Harvard University. It deals only 

 with the theory and the characteristics of 

 storage batteries. No attempt is made to dis- 

 cuss problems connected with storage-battery 

 engineering. The first chapters are devoted 

 to the laws underlying the action of storage 

 cells and to the consideration of the funda- 

 mental reactions. A short discussion of the 

 ionic theory and the energy relations in- 

 volved in the action of a storage cell is in- 

 cluded. Later chapters are given up to the 

 operating characteristics, efficiency and ca- 

 pacity, and to the general principles underly- 

 ing the methods of forming modern storage 

 battery plates. The diseases and care of stor- 

 age batteries are also discussed. In the last 

 chapter a few pages are devoted to the iron- 

 nickel-alkali cell. " Storage Batteries " is an 

 excellent little book for any one who wishes 

 a simple treatment of the theory, action and 

 care of lead-lead-peroxide storage batteries. 

 Ealph E. Lawrence 



SPECIAL AMTICLE8 

 correlation between egg-laying activity and 



YELLOW PIGMENT IN THE DOMESTIC FOWLJ- 



In the Leghorns and the so-called American 

 breeds, such as the Plymouth Eocks, yellow, 

 in the form of yellow fat,- is present in vary- 

 ing amounts in the legs and beak. In these 

 breeds, individual birds may undergo consider- 

 able change in the amount of the yellow pig- 

 ment visible. The paling or yellowing of the 



1 Paper presented before the American Society 

 of Naturalists, Philadelphia, December 31, 1914. 



2 Barrows, H. E., ' ' Histological Basis of Shank 

 Colors in Domestic Fowl, ' ' Bull. 232, Maine Agi'ic. 

 Exper. Station, 1914. 



legs has been attributed by poultrymen to vari- 

 ous environmental factors. Of recent years, 

 some individual poultrsrmen, however, have 

 claimed that paling of the legs is due to heavy 

 laying.^ The requirements of the " Standard 

 of Perfection," which controls judges in the 

 show room, as well as the common practise of 

 poultry breeders, are opposed to a belief in 

 any connection between laying and leg color. 

 Woods* under the title, " Has Leg Color Value 

 Indicating Layers ? " in the most recent dis- 

 cussion of the subject, concludes : 



Personally we believe that, as a practical guide 

 in the selection of heavy layers, . . . the leg color 

 of itself has no real value. 



So far as the writers are aware, no published 

 data are available which show in how far the 

 leg color may be of any value in selecting the 

 laying hen, and such suggestions as have 

 been made in this connection have confined 

 themselves almost entirely to a consideration 

 of the legs alone. The results tabulated in the 

 present paper show conclusively, it is believed, 

 that a close connection does in fact exist be- 

 tween the yellow pigmentation in a hen and her 

 previous egg-laying activity, and that, in Leg- 

 horns, the color of the ear-lobes is perhaps a 

 better criterion of laying activity than either 

 legs or beak and is more readily recorded. 



The hens investigated were in the egg-laying 

 contest at Storrs, Conn., and were handled 

 essentially alike. The influence of environ- 

 mental factors, therefore, can be largely neg- 

 lected. The amount of yellow was measured 

 by means of the Milton Bradley color top, 

 which, when spinning, acts as a color mixer. 

 The top readings were taken of the White 

 Leghorns listed in Tables I. and II. at three 

 different periods in October. 



In Table I., the records at the three differ- 

 ent readings have been used. A bird laying on 

 the day of record, or on a later day within the 

 month is considered to be laying and credited 



3 Rice, J. E., Circular 11, p. 42, N. Y. State 

 Dept. of Agriculture, 1910; Barron, Tom, Con- 

 necticut Farmer, September 12, 1914; Circular 

 499, Maine Agrio. Exper. Station. This is listed 

 as an abstract of Bull. 232. 



* Woods, P. T., Amer. Poultry Jour., p. 35, 

 January, 1915. 



