July 26, 1907] 



SCIENCE 



119 



Franklin Institute to Dr. Heyl is doubtless a 

 well-deserved honor, but when one reads in 

 Science for June 28, 1907, on page 1013, that a 

 definitive result is based upon the wholly un- 

 proved claim that " the distance of Algol is no 

 less than forty light years " it seems desirable 

 to emphasize the fact that in the present state 

 of our knowledge the approximate distance of 

 any particular fLxed star must still be regarded 

 as an unknown quantity. 



j. m. schaeberle 

 Ann Aeboe, 

 June 30, 1907 



SPECIAL ARTICLES 

 HENS THAT HAATE LAID TWO EGGS IN A DAY 



It is SO generally believed that it is not 

 possible for a hen to lay more than one egg 

 in a day that a few observations that show 

 this is not always true may be of interest. 



The number of eggs laid by a hen in a year 

 has been greatly increased, the maximum 

 number reported by Professor Gowell, of the 

 Maine Experiment Station, who has for a 

 number of years been breeding to increase the 

 yearly output, being 255. It would seem that 

 there is no known biological reason why the 

 maximum daily rate should be one each day, 

 any more than that the number of eggs per 

 year should be limited to a few broods. In 

 either case the ultimate limit of possibility 

 would seem to depend upon the ability of the 

 individual to assimilate and transform the 

 materials taken as food into the materials of 

 the eggs. There may be difficulties that are 

 not understood that would make it impossible 

 to develop a race of hens that would habitually 

 lay more than one egg in a day, as there have 

 been difficulties encountered in getting birds 

 that will lay every day in the year, but a 

 priori there seems to be no known biological 

 reason why a hen should not lay more than 

 one egg in a day. 



While experimenting on the fertility of eggs 

 it became necessary to keep a daily record 

 of the hens that laid. This was done by 

 means of trap nests that were arranged so 

 whenever a hen entered a nest a door was 

 dropped behind her that not only kept her 



prisoner until she was liberated by the at- 

 tendant, but excluded all others. That is, the 

 door was locked so it would not swing in 

 either direction. The ordinary numbered leg 

 bands were used to distinguish individuals. 

 The birds under observation were White 

 Wyandottes. 



The latter part of February or early in 

 March, 1906, a pullet that had recently begun 

 laying apparently laid two eggs in a day. 

 Although it seemed a clear case it was not 

 recorded as it was thought possible that a 

 mistake had been made in reading the num- 

 ber on the band. When the same hen again 

 laid two eggs on March 21, record was made 

 and to guard against possible errors in reading 

 the number on the band she was banded on 

 both legs, thus distinctly marking her, as no 

 other hen in the house had two bands. 



During March and April there are records 

 of five days on each of which this hen laid 

 two egg's. Although her record was carefully 

 kept for more than a year and a half, there 

 are no other records of her having laid more 

 than one egg in a day. It should be added 

 that the records of days on which she was 

 known to lay two eggs come during the months 

 of her greatest egg-producing activity. In 

 fact it will be seen that in the thirty-three 

 days listed in the following table the hen 

 actually laid thirty-four eggs. 



During the year and a half over which my 

 observations extend there have been a number 

 of instances of hens laying two eggs in a day, 

 but the records show that in most cases on 

 either the day before or the day after that on 

 which two eggs were deposited, no egg was 

 laid. Such cases may reasonably be accounted 

 for by supposing premature or delayed de- 

 livery, but this can not be true of the hen 



