64 White. 



implies that such a classification is very simple, which is very far from 

 the case as the following pages will abundantly testify. Characters, as 

 we have come to use the term, are definite morphological realities. 

 We divide a plant or animal up into parts, more or less arbitrarily, 

 using function, origin, form, or some other criterion as a basis, depending 

 on the special phase of biology in which one is most interested. A horn, 

 a pattern, an organ, become, through continuous familiarity with this 

 thought, absolutely definite entities, entirely separated, in our minds, 

 from the remainder of the organism. In this way, we come to think 

 of the brown eye in man, not as two or more separate character- 

 entities, but as one distinctive character, whereas from the standpoint 

 of genetics, the color and the remainder of the eye must be considered 

 separately. As systematists , it becomes hard for us to adopt the 

 physiologist's or perhaps the chemist's basis of classification, founded 

 as it is upon experimental evidence, the methods and nature of which 

 we find rather strange. We are prone to think of the inheritance of 

 characters as though they were actually handed on from cell generation 

 to cell generation, a conception very foreign to fact, for the character 

 is the combined expression of a bit of protoplasm and a specific 

 environment. 



In dividing characters into hereditary and non- hereditary classes, 

 I realize I am adopting an arbitrary classification which represents but 

 a part of the whole truth. But it represents that phase of the question 

 in which I am most interested in a clear manner. As I understand 

 the term, heredity simply implies that a given material under a given 

 specific condition or environment presents certain physical phenomena 

 which we describe as characters. We start with a standard material, 

 and if other material under the same conditions does not present this 

 character phenomena, wc hold it to be absent, but if under other con- 

 ditions it can be induced, we call it an environmental effect, and contend 

 that it is not inherited because under its normal (usual) conditions, 

 the offspring will not reproduce it. 



Looking at the character fasciation from this standpoint, it 

 becomes comparatively easy in many cases to distinguish between the 

 inherited and the non-inherited forui, but in certain cases, the difficulties 

 of classification are very greatly increased through our general ignorance 

 of the nature of the material and the various combinations of material 

 and environment necessary to produce fasciation. Environmental and 

 hereditary effects are apparently hopelessly mixed. 



