29 THE STORY. OF THE BIRDS. 
— 
surfaces without any nest. In order that they might 
roll around in a circle and not roll away or off of a 
bluff, ete., one end is made larger than the other. Of 
course the most pointed egg would be the safest, and 
hence the tendency would be increased. It is a fact 
that this style of egg tends to prevail among the flat 
reck builders of to-day. 
Again, it has been found that certain plover 
forms, which lay very pointed eges, always keep the 
three or four in their nest with the points to the cen- 
ter—replacing them when disturbed—so that the nar- 
row breast may better cover them; or possibly, as 
among some fowl forms (quails) where many eggs are 
laid, they may be made pointed so as to lie closer 
packed in two layers. It may be noticed by the 
reader in the kinship diagram (Chapter XXX) that 
these pointed eggs, running from fowls through ploy- 
ers, gulls and auks, tend along a line of strong con- 
secutive kinships. 
The pigeons lay eggs alike at both ends, but 
roundish and much elongated, while the grebes lay 
likewise equally ended eggs, but both very pointed. 
The structure and grain of the shell also bear on 
the relationship of birds, but this and other interest- 
ing things about the development of the egg and its 
hatching, ete., are beyond our scope. 
