434 Mast, L. J. Henderson on ,,The Fitness of the Environment". 



II. In jar of aquarium water + 2 drops of N/10 NaOH per 10 ccm water. 



No weed growths. 



III. In jar of normal aquarium water without weed growths 

 Fig 8. Photographed Mar. 27, X H/14. Typical animal from Jar I. 



After being photographed this individual was replaced in the aquarium. 

 The animals in Jars II and III were unchanged on Mar. 27. 



Fig. 9. Photographed April 11, X 3/4. Animal which had been removed from 

 Jar I to aquarium on Mar. 27. 



L. J. Henderson on "The Fitness of the Environment" 1 ). 



By S. 0. Mast. 



(From the Zoological Laboratory of The Johns Hopkins University.) 



In earlier days when design and special creation were topics 

 of the hour it was generally assumed that the environment had 

 been especially created for the needs of the organism, and the 

 foundation for many an argument favoring the existence and 

 omnipotence of an all-wise Creator was based on statements con- 

 cerning the fitness of its various factors. But with the appearance 

 of "The Origin of Species" in 1859 this attitude changed and it 

 came to be quite generally held that the organism had been grad- 

 ually so molded as to fit that part of the world in which it was 

 destined to live. Since that time this assumed molding process 

 has dominated practically all investigation bearing on the relation 

 between animate beings and their surroundings. Thus interest in 

 fitness and adaptation from the point of view of the environment 

 itself was all but lost. In the opinion of the reviewer the greatest 

 value of Henderson's stimulating book lies in the bearing it has 

 on again directing attention to the problem from this point of view. 



The book may be divided into three parts. The first part, 

 covering 72 pages, is devoted largely to a characterization of the 

 organism and its environment and a statement of the fundamental 

 problems concerning fitness. Our author recognizes that life has 

 various aspects. In his argument however he aims to consider it 

 only from the mechanical or physico-chemical aspect. He says 

 (p. 81), Life as we know it is a physico-chemical mechanism 2 ), and 

 it is probably inconceivable that it should be otherwise. *As such, 

 it possesses, and, we may well conclude, must ever possess, a high 

 degree of complexity." 



1) Published by The Macmillan Company, New York 1913, 317 pages. 



2) The term mechanism is frequently used to designate merely the material 

 parts of a machine. I assume, however, that Henderson uses the term in a 

 broader sense, that he intends to include in his statement, that life is a mechanism, 

 not merely the idea that it is a complex system of material parts, but that it is 

 such a system in action. If this assumption is valid his definition of life is somewhat 

 broader than that of Aristotle, Spencer and Brooks, in which they state that 

 the essence of life is adjustment. 



