ON THE CELLULAR THEOEY OF DEVELOPMENT. 101 



uuable to appreciate the full significance of the facts he de- 

 scribed in their bearing on the question of the origin of nerves. 

 Piatt approximated to the truth with regard to the third nerve 

 in her account of it as growing from the ciliary ganglion to the 

 brain, but retained the error of her predecessors in regarding 

 it as a cellular object, and not as a diflPerentiatiou of the reti- 

 culum. 



Minot has a characteristic comment on Piatt's statement. 

 He says (' Human Embryology/ p. 639), " This view rests 

 probably on erroneous interpretation of observation, for it 

 cannot be admitted that a motor nerve is formed by 

 ganglionic fibres"! (The italics are mine, as is also the 

 note of admiration.) 



