COSMIC PHILOSOPHY 



peripheral membrane. As this membrane con- 

 tinues to thicken by the integration of adja- 

 cent materials, it differentiates into two layers, 

 wrapped the one within the other, like two coats 

 of an onion. The outer layer, or ectoderm, ab- 

 sorbing larger quantities of nitrogenous matter 

 than the other, is the one which by further im- 

 mense differentiation is destined to produce the 

 bony, muscular, and nervous systems ; while the 

 inner layer, or endoderm, is destined to pro- 

 duce the digestive apparatus. Between these 

 two, by a further differentiation, arises a vascu- 

 lar layer, the rudiment of the circulatory sys- 

 tem. Now on the interior surface of the endo- 

 derm appears a grooved channel, of which the 

 edges gradually rise and fold over towards each 

 other until joining they form a tube, — the 

 primitive alimentary canal. At first nearly uni- 

 form, this channel becomes slowly more and 

 more multiform. Near the upper end it bulges 

 so as to form a stomach, while the long lower 

 portion, variously wrapped and convoluted, is 

 differentiated into the small and large intestines. 

 From various parts of the now heterogeneous 

 canal there bud forth variously organized se- 

 creting glands, — those which make saliva, and 

 those which make gastric juice, bile-cells, pan- 

 creatic cells, and intestinal follicles. While from 

 the exterior coat of the endoderm, thus won- 

 derfully transformed, there shoot out, near the 

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