FOURTH REPORT OF THE DIRECTOR \goy 57 



Among Other large problems that suggest themselves in reviewing 

 our knowledge of Devonic fishes are those relating to the habits 

 and mode of life of the creatures represented, their adaptation to 

 physical environment, the effects of such adaptation as manifested 

 in their structural modifications and subsequent racial history, and 

 finally the important topics of migration and geographical distribu- 

 tion. All of these issues, though subsidiary to the main theme, offer 

 nevertheless fruitful fields for exploration. It would take us too 

 far astray from the immediate purpose of this paper to consider all 

 of these matters seriatim, particularly as materials are already at 

 hand for those who may wish to pursue them further. For instance, 

 in regard to the habits and mode of existence of ancient forms of 

 fish life, many suggestive hints are contained in the writings of 

 Claypole, Dollo, Jaekel, Kemna and others. 



A large and very important literature exists on the subject of 

 faunal migrations in general, and geographical distribution, which 

 will be referred to later. The question of adaptation to environ- 

 ment has been less fully treated than others in the above category, 

 since, from the nature of the case, our information is more deficient 

 in this respect. The viewpoint, however, is exceedingly instructive, 

 and such light as is obtainable from it is most welcome. That we 

 have not overstated the truth must be clear to all who have gained 

 a right understanding of the working of this principle in analogous 

 cases. As convenient an illustration as any is furnished by human 

 history. One of the notable phenomena in the annals of mankind, 

 and one of the mo'st beneficent in its subtle and far-reaching conse- 

 quences, is the marvelous civilization attained by the ancient 

 Hellenes. Yet the unfolding and superb blossoming of the flower 

 of Greek genius, together with its rare beauty while it lasted — this 

 surprising spectacle utterly fails of comprehension except as we take 

 account of influences of heredity and environment. To un^lerstand 

 Athenian character and habits, or to attempt to account for that 

 civilization which flourished, as Milton says. 



Where on the Aeg^ean shore a city stands 

 Built nobly, pure the air, and light the soil, 



it is above all things imperative to understand the conditions of Attic 

 soil and climate. For as soon as one inquires critically into the 

 physical surroundings of the classical Athenian, one discovers that 

 his culture is not primarily dependent upon his peculiar character, 

 but is very largely the resultant of his outward circumstances, and 

 influenced to a marked degree by his climate. One perceives, there- 

 fore, that ample justification exists for the following statement, 

 taken from a very readable work on classical antiquity (Tucker's 

 Life in Ancient Athens), with which we will conclude our remarks 

 on this head : 



" From the bare facts that the Athenian lived in a land which 

 supplied a frugal and simple, but sufficient and wholesome diet, in 

 a climate which makes for sociable outdoor life without producing 

 languor, in an atmosphere which sets off whatsoever things are 



