120 UNIVERSALITY OF DEGENERATIVE EVOLUTION 



the vertebral column but is arrested at the first 

 lumbar vertebra. There a considerable number of 

 special nerves leave it, forming a mass of branches 

 like a horse's tail. Along the centre of these 

 nerves, in the middle line, a slender filament 

 represents the spinal cord to the extremity of the 

 coccyx. This filament is the flum terminate, the 

 spinal cord in a condition of degeneration. 



5. The Digestive System. The caecum and its 

 vermiform appendage, are well known to be organs 

 which have degenerated. 



6. The Vascular System. In quadrupeds the 

 intercostal veins are vertical, the blood consequently 

 flowing against gravity. These veins contain valves 

 which indirectly facilitate the upward and onward 

 flow of the blood by preventing it from running 

 back. Man, being a biped with a vertical thorax, 

 is provided with intercostal veins that are almost 

 horizontal. The ancestral valves being no longer 

 indispensable are in a condition of degeneration. 



7. Sense Organs. In the olfactory organ there 

 remains a degenerate Jacobson's organ. In the 

 organ of sight there is a third eyelid in a state 

 of degeneration. In the organ of hearing there 

 remains on the shell of the ear a kind of point 

 (Darwin's point) which is the last remaining vestige 

 of the ancestral elongated and pointed ear. 



8. Genito-urinary System. There is a whole 

 series of rudimentary organs in the genito-urinary 

 system of the higher animals. As is well known, 



