140 .CHARLES 



ancestors of humanity as aquatic animals, allied to the 

 mudfish ; for our lungs are known to consist of modified 

 swim-bladders, which must once have served our remote 

 progenitors in the office of a float. The gill-clefts on 

 the neck of the human embryo still point to the spot 

 where the branchige once, no doubt, existed. Our prim- 

 ordial birthplace appears to have been a shore washed 

 twice a day by the recurrent tides. The heart then took 

 the shape merely of a simple pulsating vessel ; and a 

 long undivided spinal cord usurped the place of the 

 vertebral column. These extremely primitive ancestors 

 of man, thus dimly beheld across the gulf of ages, must 

 have been at least as simply and humbly organised as 

 that very lowest and earliest of existing vertebrates, the 

 worm-like lancelet. 



From such a rude and indefinite beginning natural 

 selection, aided by the various concomitant principles, 

 has slowly built up the pedigree of man. Starting 

 from these remote half-invertebrate forms, whose vague 

 shape is still perhaps in part preserved for us by the soft 

 and jelly-like larva of the modern ascidian, we rise by 

 long stages to a group of early fishes, like the lancelet 

 itself. From these the ganoids and then the lung-bearing 

 mudfish must have been gradually developed. From 

 such fish a very small advance would carry us on to the 

 newts and other amphibians. The duck-billed platypus 

 helps us slightly to bridge over the gap between the 

 reptiles and the lower mammals, such as the kangaroo and 

 the wombat, though the connection with the amphibians 

 is still, as when Darwin wrote, highly problematical. 

 From marsupials, such as the kangaroo, we ascend 

 gradually to the insectivorous type represented by the 



