38 FOOT-NOTES TO EVOLUTION. 
All of these questions, and thousands more which will 
suggest themselves at once to every student of embry- 
ology, are problems which receive no adequate explana- 
tion on the supposition of special creations. With the 
theory of evolution as a basis, the answers are easy. 
They are inheritances from ancestral conditions. In 
the terms of evolution they remain because the history 
of the individual is a more or less detailed recapitula- 
tion of the history of the race. 
“ The truth of this assumption is easily tested. The 
conclusions of embryology must be in full accord with 
those of geology, or one or the other must be wrong. 
In the rocks we have an indisputable record of the suc- 
cession of the forms of life, and the conclusions of em- 
bryology must point to a similar succession. 
“While neither our limits nor the character of the 
present article will allow anything like a discussion of 
the embryological evidence in support of evolution, a 
few examples will serve to indicate its character. 
“In the development of all eggs the earlier stages 
are essentially alike, or easily reducible to a common 
type. It is only in the later stages that 
the variations occur that are to convert 
one egg into a fish, another into a 
chicken. There are, it is true, minor 
differences from the start, but these are largely to be 
explained on mechanical grounds. An egg differs from 
the other cells in the tissues of the parent chiefly in its 
capacity to reproduce the species. It divides again and 
again, and the resulting cells build anew the parent 
form, but in the character of this division or ‘segmenta- 
tion’ many variations are recognised. In some the 
eggs are small and composed entirely of protoplasm, 
and here the segmentation is regular, but other eggs are 
larger, and this increase in size is due to the addition of 
Similarity of 
early stages in 
embryonic life. 
