Proofs of Ei^olutlon. 297 



the body are developed. When an egg is formed by a mnl- 

 tiplicity of cells, it separates into three distinct layers, 

 called the ecto-blast, the endo-blast, and the nieso-blast, 

 from which are developed by differentiation the three great 

 life-centres, namely, the nervous system, the nutritive sys- 

 tem, and the blood system; and from these follow the mul- 

 titiidinous branchings to the highest stage of differentiation 

 in the ontogenic series. Tracing any one of these grou})s, 

 as the nervous system, we find it differentiates once more, 

 forming the cerebro-spinal and ganglionic systems, each 

 having different functions. The cerebro-spinal again differ- 

 entiates into two systems, the voluntary and reflex,— these 

 still again branching out into sensory and motor centres 

 and fibres. The sensory -fibres branch out into the five 

 senses with their separate functions. Take any one of the 

 senses, as touch, and we observe that the nerve-fibres are 

 not all alike. Some are sensitive to heat and cold ; others 

 to pressure. The nutritive and blood systems have, like- 

 wise, their special lines of differentiation, culminating in 

 all the different organs, parts and functions of the animal 

 body. And this is the process of every life and every 

 birth. 



One of the most startling as well as one of the strongest 

 proofs of evolution, is found in the fact that in Embryonic 

 growth, each individual i)asses through all the successive 

 stages which have ])receded in the line of its tribal history. 

 In other words, philogeny is repeated in ontogeny ; the race 

 in the individual. At a certain point, the embryo ceases to 

 personate its ancestors, and commences to take on the form 

 peculiar to its own kind. Professor Haeckel, in his " Evo- 

 lution of Man," has given a series of plates showing the 

 development of the embryos of the fish, salamander, tor- 

 toise, chick, hog, calf, rabbit, and man. At certain stages 

 in their ])re-natal development, there is an exact resemblance 

 of form among them all, each becoming specialized as it 

 approaches the time of birth. At one period of its growth 

 the human embryo has the long, free, swinging tail of the 

 races below it. 



Whither does all this array of facts lead ? What expla- 

 nation can the creationist give ? If man was fashioned at 

 once, why drag him to nativity through all the forms of 

 the brute-creation ? Why mascpierade liim in tlu; guise of 

 the dumb, ferocious, and soulless l)rut('s ? There is no 



