64 Heredity and Environment 



first to bring order out of chaos by dealing with traits or char- 

 acters singly instead of treating all together. He made careful 

 studies on the inheritance of weight and size in the seeds of 

 sweet peas, and on the inheritance of stature, eye-color, intel- 

 lectual capacity, artistic ability and certain diseases in man. At 

 the same time that Galton was thus laying the foundations for a 

 scientific study of heredity by dealing with characters separately, 

 another and an even greater student of heredity, Gregor Mendel, 

 was doing the same thing in his experiments with garden peas, 

 but inasmuch as Mendel's work remained practically unknown 

 for many years, Galton has been rightly recognized as the founder 

 of the scientific study of heredity. 



Of course, neither Galton nor anyone else who has followed 

 his method of dealing with the characters of organisms singly, ever 

 supposed that such characters could exist independently of other 

 characters and apart from the entire organism. This is such a 

 self-evident fact that it may seem needless to mention it, and yet 

 there have been critics who have believed, or have assumed to 

 believe, that modern students of heredity attempt to analyze or- 

 ganisms into independently existing characters, whereas in most 

 cases they have done only what the anatomist does in treating 

 -separately the various organs of the body. 



HEREDITARY RESEMBLANCES AND DIFFERENCES 



The various characters into which an organism may be analyzed 

 show a greater or smaller degree of resemblance to the corre- 

 sponding characters of its parents. Whenever the differential 

 cause of a character is a germinal one the character is, by defini- 

 tion, inherited ; on the other hand, whenever this differential cause 

 is environmental the character is not inherited. While it J*s true 

 that inheritance is most clearly recognized in those characters in 

 which offspring resemble their parents, even characters in which 

 they differ from their parents may be inherited, as is plainly 

 seen when, in any character, a child resembles a grandparent or a 



