34^ Raymond Pearl 



it be a gradual change according to some definite curve, loga- 

 rithmic or other, or would it be a sudden and entirely irregular 

 change from the abnormal to the normal ? To answer these 

 questions the attempt was made to save every egg laid by this 

 bird over a considerable period of time. With the exception of 

 one egg (the 15th laid) every egg laid before July i, 1908, was pre- 

 served. During the period this hen laid 87 eggs. 



The appearance of the first 12, and the i8th, 30th, 42d, and 54th 

 of these eggs is shown in Plate I. After the first dozen eggs the 

 change of the egg form was so gradual that it does not seem advis- 

 able to take the space to reproduce a photograph of each individ- 

 ual egg. Instead it has been deemed sufficient to take for illus- 

 tration every 12th egg beginning with the i8th. 



The length, maximum breadth and length-breadth-index (100 

 times the breadth divided by length) of each egg, together with 

 date of laying, are shown in Table I. 



From the data of Table I, and the photographs in Plate I the 

 following points are to be noted : 



1 The first egg laid by hen No. 183 had a greater length, a 

 smaller breadth, and consequently a lower index, than any other 

 egg which she ever laid. Since the abnormality of this hen's egg 

 in general existed chiefly in these dimensions it may be said that 

 the first egg laid deviated more widely from the normal than did 

 any other egg laid by the hen. 



2 In the eggs successively produced by this hen there is in gen- 

 eral a decrease in length and an increase in breadth, leading to an 

 increase in the value of the index. In other words, the eggs laid by 

 this hen become progressively more nearly normal in form with 

 continued production. 



FOOTNOTE TO TABLE I 



*The measurements of the eggs were made for the most part with a micrometer cahper reading to 

 hundredths of a millimeter, and the dimensions were recorded to the second decimal place. In some 

 instances it was necessary to make the measurements with a caliper reading only to tenths of a milli- 

 meter. In all cases in making the divisions for the index the lengths and breadths were used to the 

 total recorded number of decimal places. In preparing Table I length and breadth have been recorded 

 to the nearest tenth. It is possible under these circumstances that the second decimal place in the index 

 may not exactly agree with what is obtained by dividing the tabled breadth X lOO by the tabled length. 



