THE PATH OF EVOLUTION 



life does, in the fertilized, almost microscopic, cell, 

 without visible difference between it and the corre- 

 sponding germ cell of other mammalia. This cell, 

 at first about ^ qf an inch in diameter, as it grows, 

 divides and redivides, as an amoeba might do; then 

 a grouping of these cells into a long, narrow disk that 

 folds over into a tube-like shape, marks the com- 

 mencement of the spinal marrow. The form thus 

 made, the lowest vertebrate, the "Amphioxus," per- 

 manently retains. The further metamorphoses are 

 essentially similar to those described in the hatching 

 of a fowl's egg, the embryo as it matures passing 

 successively through stages in which it is nearly un- 

 distinguishable from the embryo of a fish, tortoise, 

 chicken, dog or other vertebrate in relatively the same 

 stage of development. The length of embryonic life 

 being so much longer in man than in the above- 

 named vertebrates, the similarity referred to continues 

 so much the longer in the advancing stages, in pro- 

 portion to their nearer resemblance to him in their 

 general structure. The birth of every man is thus a 

 type of his evolution through long past ages. 



When born, man, is of all animals, the least de- 

 veloped and the most helpless. Without even the 

 power of moving, with less apparent intelligence 

 than an Ascidian, he is dependent more than any 

 other animal, for many months for life itself, abso- 



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