82 MAYNIE R. CURTIS 



SUMMARY. 



1. During the last six years more than three thousand' 

 different domestic fowls, which have been kept at least one year 

 at the Maine Agricultural Experiment Station, have laid but 

 three triple-yolked eggs. 



2. Each of these eggs wa^ laid by a different individual 

 and in each case the triple-yolked egg was one of the first eggs 

 pioduced by a young pullet. 



3. Young pullets also show a decided tendency to produce 

 double-yolked eggs when they first begin to lay. About 20 per 

 cent, of the pullets which lay before they are seven months old 

 lay among their first eggs one or more with two yolks. 



4. Nearly 80 per cent, of the individuals of the flock never 

 lay a double-yolked egg. 



5. Mature birds also sometimes produce double-yolked eggs; 

 but most such birds have also produced one or more when they 

 were young pullets. 



6. There has been no bird in the experiment station flock 

 with which the laying of double-yolked eggs wat> "habitual" 

 although there are some which have produced several such eggs. 



7. The production of an egg with two or three yolks repre- 

 sents the extreme of rapid egg production, other forms of which 

 are found in the production of TWO eggs united by a membranous 

 tube; two eggs at the same time; two eggs at different times on 

 the same day and a daily egg production where the eggs are laid 

 earlier on each successive day. 



8. The two yolks of a double-yolked egg may have all the 

 egg envelopes in common, indicating that they have passed the 

 entire length of the duct togethei ; or each may possess one or 

 more separate envelopes. There are also all the possible inter- 

 mediate forms indicating that the two yolks in a common shell 

 may unite at any point between the mouth of the funnel and 

 the isthmus. When two eggs come together after the first has 

 entirely passed the anterior end of the isthmus the result is the 

 production of two eggs at the bame time. 



9. Various disturbances of the normal processes of egg pro- 

 duction may bring two yolks together in the oviduct. Double- 

 yolked eggs evidently do not always represent simultaneous- 



