226 



SCIENCE 



[N. S. Vol. LIV. No. 1393 



of the International Egg Laying Contest at 

 Storrs during the year 1913-'14 and 1914- 

 '15 ^ are laid beside those presented here from 

 the Vineland data. 



The essential constants appear in the ac- 

 companying table. This gives the per cent, 

 of the flock which did and which did not lay 

 during the months of the first year in which 

 any considerable projwrtion of the birds did 

 not lay. The average annual production for 

 these birds in the first year of both the Storrs 

 (1913-'14 and 191^' 15) and the Vineland 

 (1916-' 17) contests and in the second year 

 (1917-' 18) of the Vineland contest are shown. 

 While the actual differences in egg preduction 

 are the data of practical significance, com- 

 parison between the three series is facilitated 

 by expressing the differences between these 

 annual means for the birds of the two classes 

 as percentages of the actual annual average 

 productions'* of the flock. 



Considering first the records of the pullet 

 year we note that for the Storrs series the 

 birds which laid in any given month show an 

 average annual (pullet year) egg production 

 of from 27.4 to 82.8 eggs higher than those 

 which did not lay or from 17.9 to 54.1 per 

 cent. For the Vineland series the difference 

 in the production of the two groups ranges 

 from 36.7 to 65.5 eggs or from 21.1 to 37.6 

 per cent. Thus the difference in the annual 

 egg production of the birds which did and 

 which did not lay in any given month, as 

 well as the percentage of the birds which 

 are not laying, varies greatly according to 

 the month considered. During the months 

 of November, December and January the 

 percentage differences in the annual produc- 

 tion of the two gi'oups of birds is higher in 

 the Vineland than in the Storrs series 

 whereas for the other months of the eight 

 considered the reverse is true. The average 

 percentage difference is 30.4 in the Storrs 

 series and 26.6 in the Vineland series. 



3 Harris, Blakeslee and Kirkpatrick, loc. cit., 

 p. 42. 



* These are 153.19 eggs for the first year at 

 Storrs, 174.05 eggs for the first year at Vineland, 

 and 139.79 eggs for the second year at Vineland. 



Thus the constants show conspicuous differ- 

 ences of great practical significance in the 

 first (pullet) year records of birds which did 

 and those which did not lay during the 

 individual months of the first year. The 

 results for the first year records at Storrs and 

 the first year records at Vineland are in fair 

 agreement. 



Turning to the second year means we note 

 that for each of the eight months of the first 

 year used as a basis of selection for an in- 

 crease of second year preduction, the second 

 year record of birds is higher if they laid dur- 

 ing the special month under consideration in 

 the first year than if they did not lay in that 

 month. The differences between the groups 

 amount to about two dozen eggs or more per 

 bird in five of the eight months considered. 



It is clear, therefore, that so simple a 

 criterion as laying vs. non laying in the first 

 year may furnish a criterion of some value 

 for the selection of the birds to be retained 

 in the flock for breeding and for second year 

 production. 



J. Arthur Harris, 

 Harry E. Lewis 



THE AMERICAN CHEMICAL SOCIETY 



(contimied) 

 nrvisiON OF ixdustrial axd engineering 



CHEMISTRY 



H. D. BatcheloT, cliairman 

 H. E. Howe, secretary 



Symposium on Drying. Charles 0. Lavett, 

 chairman 



The rate of drying of solid materials: W. K. 

 Lewis. 



The theory of atmospheric evaporation: W. H. 

 Carrier. 



The compartment dryer: W. C. Carrier and A. 

 E. Stacet. a discussion of the relative merits 

 of the continuous and compartment dryers. 



Direct heat rotary drying apparatus: E. G. 

 Merz. The paper was treated under the following 

 heads: (1) The kinds and characteristics of di- 

 rect heat rotary dryers. (2) The fields of appli- 

 cation of such drying apparatus to the industries 

 where they can be used to advantage. (3) The 



