SIZE, SHAPE AND PHYSICAL CONSTITUTION OF THE EGG. I2JT 
Utter. It has also shown that the variation in successive eggs 
is as great at the end of the second as at the beginning of the 
first year’s laying. 
Discussion of Results. 
Only a beginning of the analysis of the factors which produce 
variation in the eggs of the domestic fowl is possible from 
the results of this investigation. 
Since the individual variation in egg characters is less than 
race variation, and since the association of various pairs of 
egg characters is greater within the egg of an individual than 
within the eggs of the race, it is concluded that an individual 
inherits or, at least, possesses at sexual maturity, the tendency 
to lay eggs of a certain particular and individual shape, size 
and physical constitution. 
The seasonal and cyclic fluctuations in the eggs of the indi- 
vidual on the other hand show that this predisposition toward 
eggs of a particular type and size may be influenced by physio- 
logical and possibly also environmental conditions. 
That the individuality in egg characters is related to individ- 
uality in other characters seems certain. The fact that r he 
large varieties of hens lay larger eggs than bantams indicates 
that within broad limits the size of the egg is related to body 
size. The insignificance of the correlation coefficient between 
egg size and body size for the egg of the individuals studied 
however shows that this relation does not necessarily obtain 
within narrow limits. It is not possible to decide the limits of 
the relation of body size to egg size from so small a number 
of individuals. The point is open to further investigation. 
In the study of egg characters it must be kept in mind that 
eggs are quite different material than is usually employed in 
biological studies of variation. They are not organs or parts 
of ^organs that owe their size and shape to growth, i. e., the 
proliferation of the cells of which they are made up. Each 
egg is one modified cell and represents the accumulated results 
of the activity of a great many cells, not a part of it. The 
different parts of the egg arise from different organs or parts 
of organs (the ovary and the parts of the oviduct) and by 
quite distinct physiological processes (yolk deposition and 
albumen, membrane, and shell secretion.) 
