THE THEORIA GENERATIONIS. 275 



ing, unorganized substance, and the paths along which it flows 

 become the lumina of the uriniferous tubules and the ureter. 



We know that Wolff's main error lay in grossly underestimat- 

 ing the complexity of the problem he attempted to solve. This 

 has always been a great pitfall in attempting an explanation of 

 life. Perhaps it is well that it is so, for Wolff would hardly have 

 had the heart to attempt it if he could have seen the problem with 

 our eyes. And may not we, too, daily commit the same blunder 

 when we lend a willing ear to those who regard living protoplasm 

 as nothing more than a " complex chemical compound " ? 



Wolff accepted a simple substance as the basis of life because 

 he was unable to detect structure in the embryo beyond a cer- 

 tain limit which happened to coincide with the limits of magni- 

 fication of his lenses. We should suppose that Wolff would 

 have longed for a better lens and have at least suspected the 

 possible existence of some kind of structure beyond that which 

 he could detect. Instead of doing this, however, he writes the 

 following remarkable sentences which will draw a smile from 

 the modern searchers after centrosomes ^: "No one has ever 

 yet, with the aid of a stronger lens, detected parts, which he 

 could not perceive by means of a weaker magnification. These 

 parts either have not been seen at all, or they have appeared 

 of sufficient size. That parts may remain concealed on account 

 of their infinitely small size and then gradually emerge, is a 

 fable." There it is in cold Latin ! Was Wolff merely nodding 

 when he wrote this, or was he trying to hoodwink the pre- 

 delineationists into believing that he had seen everything that 

 was worth seeing in the embryo .-' 



In the closing paragraph of his great work on the develop- 

 ment of the intestinal tract, a work which appeared in 1768, 

 some nine years after the Theoria, Wolff seems to rise to a 

 clearer perception of the complexity of the problem. He 

 appears to be far more doubtful concerning the way in which 

 simple matter becomes organized. Referring to the develop- 

 ment of the anterior body wall, he says 2; "This is one of the 



1 Theoria, Sect. 166. 



2 Wolff, C. F. Ueber die Bildung des Darmkanals im bebriiteten Huhnchen. 

 Uebersetzt von J. F. Meckel. Halle, 1812, p. 245. 



