286 WILLIAM LAWRENCE TOWER. 



for their practice and theory, because of the fact that the char- 

 acters of organisms often stand out sharply and behave with 

 distinctness in the processes which follow reproduction. 



That many of the characters in organisms are distinct and 

 behave in the sharp, alternative fashion described by the 

 Mendelians, there can be no reasonable doubt. To deny the 

 existence of these sharply defined, predicable behaviors in in- 

 heritance is to deny the evidence of our senses, and accuse a 

 considerable body of reputable workers of inability to make 

 accurate observations. The fundamental question is, do these 

 unit characters, or lesser entities, occupy in the organism the 

 mosaic relation and have the capacity for the mosaic rearrangement 

 which is assumed hy most Mendelians and by the followers of De 

 Vries? 



We must not be diverted from the main question by any fancied 

 injury to our biological orthodoxies by the Neo-Mendelians' array 

 of factors, determiners, allelomorphs, gametic couplings, latencies, 

 etc., because these represent only the symbols of processes at 

 present unknown, although the results of these unknown processes 

 are observable, predicable, capable of control and modification. 



Many, unable to accept the consequences which they believe 

 to be the logical outcome of the unit character conception and 

 the mosaic composition of organisms, take refuge in speculations 

 in which the organic individual is compared to inorganic crystals, 

 and state their position as follows: 



In the inorganic world the attributes and qualities of a par- 

 ticular substance are due to the interaction of the component 

 molecules and atoms, resulting in manifestations of one kind or 

 another, which, as far as the mass is concerned, are essentially 

 equivalent to the characters found in organisms. That is to say, 

 in a crystal of copper sulphate the crystalline form and blue color 

 are not due to a series of representative particles, or to unit 

 characters, but they are due to the arrangement of the component 

 molecules of copper sulphate and water of crystallization; in 

 short, to a host of complex interactions of the component mole- 

 cules. Copper sulphate crystals, in order to retain their specific 

 identity, must consist of a definite proportion and arrangement 

 of these molecules, and there is no a priori reason why it is any 



