January 24, 190S] 



SCIENCE 



149 



(1-4), -when we attempt to determine at what 

 point in tlie chain of processes a new character 

 is set in motion, in course of investigation of 

 the initiation or origin of new characters. 



Diagram ilhistratiiig the reciprocal influences 

 of heredity, ontogeny, environment and selection. 

 Arrows across the circle would represent these 

 relations still more completely. 



1. For example, as concerns heredity, con- 

 sider the slow " mutations of Waagen " or the 

 rapid " mutations of De Vries." According 

 to an internal theory the point of origin 

 would he expressed by a formula presenting 

 the theory that mutations originate in 

 heredity, namely : 



ff o E s . 



The experiments of MacDougaP and others 

 in the New York Botanical Gardens showing 

 that mutations are sometimes set in motion 

 externally or through environment, would be 

 represented by the formula: 

 H= o E' s . 



2. Similarly, as concerns ontogeny^ the 

 theory of the phenomena of " organic or coin- 

 cident selection " might be represented by the 

 following successive f oiTaiilse : 



H O^ E s =^ first or ontogenetic phase. 



ffO'ES ^second phase, or phase of coincidence 

 of heredity with ontogeny. 



H° 0' E S' = third phase, in which coincident onto- 

 genetic adaptations and hereditary 

 predispositions are selected. 



Here again the originating cause may be 

 the environment, 'in which case the formula 



° MacDougal, " Heredity find the Origin of Spe- 

 cies," The Monist, January, 1906. Rept. Dept. 

 Bot. Research (extract from fifth Year Book, 

 Carnegie Inst., pp. 119-135), p. 129. 



should be written ES 0^ ff, S*. This is a 

 further example of the constant operation of 

 the " inseparable law." 



3. The initial influence of environment in 

 the origin of new characters (or revival of 

 ancestral characters) has been well illustrated 

 recently in the interesting experiments of 

 Beebe* in the New York Zoological Park, in 

 which the eggs of the same mother bird 

 (Scardafella, the scaly dove) were subjected 

 to two extremes of environment, all other 

 factors being excluded, with two types of 

 plumage resulting. Here the formula is 

 clearly : 



H 0= E' s . 



4. Finally, as concerns selection, while it is 

 admitted that this factor originates nothing, 

 there are periods of intense struggle for exist- 

 ence when selection takes most active part in 

 the perpetuation of certain characters and 

 elimination of others and is thus indirectly 

 initiative. 



We are forced to the conclusion that all 

 hypotheses which treat of these four processes 

 as separable in a state of nature are unsound; 

 that all methods of investigation which pro- 

 ceed on such assumption are unsound. At 

 the same time investigation and experiment 

 may proceed to test two working hypoth- 

 eses: First, that while inseparaile from the 

 others, each process may in certain conditions 

 become an initiative or leading factor; second, 

 that in complex organisms one factor may he 

 initiative in one group of characters while 

 another factor may at the same time he initia- 

 tive in another group of characters, the in- 

 separable action bringing about a continuously 

 harmonious result. 



Application op this Law to the Titano- 

 THERES. — The hypothesis of the simultaneous 

 operation of several factors on different groups 

 of characters could only suggest itself to a 

 paleontologist working upon a very complex 

 organism in which an almost countless num- 

 ber of characters is simultaneously evolving. 

 The analysis of these processes as applied to 



* Beehe, C. William, " Geographic Variation in 

 Birds, with Especial Reference to the Effects of 

 Humidity," Zoologica-, N. Y. Zool. Soc, Sept. 25, 

 1907, pp. 1-41. 



