THE ASCENT OF THE BODY, 71 



for an analogue will readily find it. It is a circum- 

 stance of extraordinary interest that there should be 

 living upon the globe at this moment an animal 

 representing the actual transition from Invertebrate 

 to Vertebrate life. The acquisition of a vertebral 

 column is one of the great marks of height which 

 Nature has bestowed upon her creatures ; and in the 

 shallow waters of the Mediterranean she has pre- 

 served for us a creature which, whether degenerate 

 or not, can only be likened to one of her first rude 

 experiments in this direction. This animal is the 

 Lancelet, or Amphioxus, and so rudimentary is the 

 backbone that it does not contain any bone at all, but 

 only a shadow or prophecy of it in cartilage. The 

 cartilaginous notocliord of the Amphioxus nevertheless 

 is the progenitor of all vertebral columns, and in the 

 first instance this structure appears in the human 

 embryo exactly as it now exists in the Lancelet. But 

 this is only a single example. In living Nature there 

 are a hundred other animal characteristics which at 

 one stage or another the biologist may discern in the 

 ever-changing kaleidoscope of the human embryo. 



Even with this addition, nevertheless, the human 

 infant is but a first rough draft, an almost formless 

 lump of clay. As yet there is no distinct head, no 

 brain, no jaws, no limbs; the heart is imperfect, the 

 higher visceral organs are feebly developed, every- 

 thing is elementary. But gradually new organs loom 

 in sight, old ones increase in complexity. By a magic 

 which has never yet been fathomed the hidden Potter 

 shapes and re-shapes the clay. The whole grows in 

 size and symmetry. Resemblances, this time, to 

 the embryos of the lower vertebrate series, flash out as 



