752 THE POPULAR SCIENCE MONTHLY. 



plants, or I might shortly say, of all living creatures to one an- 

 other. It used to be assumed that the highest plants and highest 

 animals were to be compared together, but all attempts to make 

 this comparison rationally were unsuccessful ; and it was only 

 when an old member of this society, Mr. Charles Darwin, pointed 

 out that animals and plants had sprung from one common an- 

 cestor and had diverged in different directions that the various 

 relationships became intelligible. I well remember that when 

 learning botany it puzzled me greatly to understand why the 

 shape of the ovary, the nature of the ovule, and the position of 

 the embryo should be such important characters in determining 

 the genus of plants, and I devoutly wished that plants had been 

 made in such a way that one could settle their nature by charac- 

 ters visible to the naked eye and not requiring a pocket micro- 



Fig. 1. — Chick. Fig. 2.— Tortoise. Fig. 3. — Hog. Fig. 4. — Man. 



(After Haeckel.) 



scope. Bat the reason for all this at once became evident when 

 the Darwinian doctrine showed that it is in these embryonic 

 characters that relationships are to be discovered and that it is in 

 later development that differences occur. As Haeckel has shown, 

 the embryos of the fowl, the tortoise, the hog, and the man, are all 

 nearly alike in the early stages of fcetal life (Figs. 1, 2, 3, and 4), 

 utterly different as these creatures may be when they have at- 

 tained their full development — the Darwinian doctrine has 

 thrown a flood of light on the relationship of plants and animals, 

 and shows us that when animals have got as it were on the 

 wrong track, however far they may go in it, they never come to 

 anything very good. 



Nobody expects much of a jellyfish. Its soft, pulpy substance 

 is incapable of anything but the simplest movement, and no ani- 

 mal that has not something hard to steady it can greatly excel 

 the jellyfish. The soft mollusks which use their hard casing only 

 for protective purposes, like the oyster and the snail, are bound 

 to stay low in the scale of existence, and the highest mollusk (the 

 octopus) appears to be striving after something better, but only 



