146 Slouj' Citij Academy of ^eiviicG and Letters. 



from another. Von Baer, one of the great students of 

 embryology, is quoted by Darwin as follows: "In my 

 possession are two little embryos in spirits, whose names 

 I have omitted to attach, and at present I am quite un- 

 able to say to what class they belong. They may be 

 lizards, or small birds, or very j^oung mammanlia, so 

 complete is the similarity in the mode of formation of 

 the head and trunk in these animals. The extremities, 

 however, are still absent in these embryos. But, even if 

 they had existed, in the earliest stage of their develop- 

 ment we should learn nothing, for the feet of lizards and 

 mammals, the wings and feet of birds, no less than the 

 hands and feet of men, all arise from the same funda- 

 mental form." 



From what has already been said, we can see a de- 

 velopment in parallel lines following after each other. 

 The first was begun myriads of ages before the second 

 one, and was a development of the inorganic world. 

 There was a breaking up, ai separating of the materialsi 

 of the rocky crust by the agency of heat and water, and 

 a gathering together of the detritus under new combina- 

 tions and in new places and conditions to prepare for 

 the organic life, which was, in the future, to come into 

 being. In this development or change of the inorganic 

 materials of our earth, there must have been produced 

 that which is the foundation of all life, from the lowest 

 to the highest, protoplasm. This word is a compound of 

 two Greek words, protos, first, and plasma, moulded. It 

 is a half -fluid, sticky material full of numberless minute 

 granules, in ceaseless and rapid motion. It is a complex 

 union of the elementary substances, carbon, hydrogen, 

 oxygen and nitrogen. From this protoplasm was devel- 

 oped, when the proper conditions had arrived, the second 

 line of development, organic life, plant life could have 

 been developed and have existed in the seas while their 

 waters were still very much too hot to have supported 

 any kind of animal life. Dana says that in the hot 

 springs on Pluton Creek, Cal., Prof. W. H. Brewer ob- 

 served confervae in waters of 140° to 149° F., and similar 

 algae in water at 200° temperature. Such a heat as this 

 would be fatal to animal life of any kind. 



