62 MAYNIE R. CURTIS. 



them. This bird had laid on each of the three preceding days, 

 but did not lay on either of the two following days. The pro- 

 duction of the two eggs in one day in this case may have been 

 due to a shortening of the time between the last two ovulations 

 in the clutch although it is also possible that it was due to the 

 early expulsion of the last egg. 



An authentic record of a White Wyandotte pullet which showed 

 a rate of production high enough to cause several instances of 

 the production of two eggs in a day has been published by Drew. 1 



Other cases have been recorded where two separate eggs have 

 been produced at the same time. As in the preceding case all 

 such records must be most critically investigated since an egg 

 may have been overlooked the last time the nest was used or a 

 bird may have entered a nest, laid and gone out while another 

 bird was standing on the open trap door. A second bird may 

 later be found in the nest with two eggs. Therefore, no record 

 of two eggs at one time is accepted at this plant unless the two 

 eggs so closely resemble each other and differ so decidedly from 

 the average eggs of the breed that there can be no doubt that 

 they were produced by the same bird. Four such undoubted cases 

 of the laying of two separate normal eggs at one time have oc- 

 curred at this plant. Two of the birds producing these had 

 laid on the preceding day but did not lay on the following. 

 These cases then must be accounted for by the unusually rapid 

 succession of the second egg. One of the birds produced an 

 egg on both the preceding and following days. In this case 

 also the only possible explanation is an abnormally rapid period 

 of egg production. In the fourth case the bird produced an egg 

 on the following but not on the preceding day. This case may 

 represent abnormally rapid production, or it may simply be that 

 the first egg failed to be discharged from the duct until the second 

 one was completely formed. These cases all show that an egg 

 may overtake its predecessor after they are both completely 

 formed. In some cases this is most probably due to a decrease 

 in the normal minimum time between ovulations, although the 

 same effect (i. e., production of two eggs at the same time) is 



1 Drew, Gilman A., " Hens that have Laid Two Eggs in a Day," Science, Vol. 26, 

 N.S., pp. 119-120, 1907. 



