August 30, 1901.] 



SCIENCE. 



317 



try or the kinds of habitat, and the proper 

 number might take the place of the varietal 

 or sub varietal name. Thus the northeast- 

 ern skunk might be designated Mephitis 

 mephitica 74 and the southeastern skunk ' 

 Mephitis mejMtica 75 (adopting the Dewey 

 system of numerals). • The Maine skunk 

 would then be 741 ; that of New York 

 747, and so on. This much for a sugges- 

 tion. 



So likewise for the morphologist the 

 coming century will bring new aims and 

 new methods. No longer will the con- 

 struction of phylogenetic trees be the chief 

 end of his studies, but a broad understand- 

 ing of the form producing and the form 

 maintaining processes. The morphologist 

 will more and more consider experiment a 

 legitimate method for him. The experi- 

 mental method will, I take it, be extended 

 especially to the details of cytology, and 

 here cytology will make some of its great- 

 est advances. 



Not only will the old subjects be studied 

 by new methods, but we have every reason 

 to believe that new sub-sciences will arise 

 during the twentieth century as they did 

 during the nineteenth. Of course we can- 

 not forecast all these unborn sciences, 

 as cj^tology and neurology could hardly 

 have been forecast at the beginning of 

 the nineteenth century. But we can see 

 the beginnings of what are doubtless to be 

 distinct sciences. Thus comparative phys- 

 iology is still in its infancy and is as yet 

 hardly worthy of the name of a science ; 

 there is no question that this will develop 

 in the coming decades. Animal behavior 

 has long been treated in a desultory way, 

 and many treatises on the subject are 

 rather contributions to folk-lore than to 

 science. But we are beginning to see a 

 new era — an era of precise, critical and ob- 

 jective observation and record of the in- 

 stincts and reactions of animals. One day 

 we shall reach the stage of comparative 



studies, and shall have a science of the 

 ontogeny of animal instincts. This will 

 have the same importance for an interpre- 

 tation of human behavior that comparative 

 anatomy and embryology have for human 

 structure. 



Prominent among the advances of the 

 century will be the ability to control bio- 

 logical processes. We shall know the fac- 

 tors that determine the rate of growth and 

 the size of an animal, the direction and 

 sequence of cell- divisions, the color, sex 

 and details of form of a species. The 

 direction of ontogeny and of phylogeny 

 will be to a greater or less extent under 

 our control. 



The study of animals in relation to their 

 environment, long the pastime of country 

 gentlemen of leisure, will become a science. 

 Some day we shall be able to say just what 

 conditions an animal's presence at anyplace; 

 and, more than that, we shall be able to 

 account for the fauna — the sum total of ani- 

 mal life of any locality — and to trace the 

 history of that fauna. This is at least one 

 of the aims of animal ecology. It is a re- 

 proach to zoology that the subject of ani- 

 mal ecology should lag so far behind that 

 of plant ecology. When zoologists fully 

 awaken to a realization of what a fallow 

 field lies here this reproach will quickly be 

 wiped out. As it is, we have a notion that 

 the factors determining the occurrence of an 

 animal or of a fauna are too complicated to be 

 unraveled. As a matter of fact, the factors 

 are often quite simple. Let me illustrate 

 this by some studies I have made this sum- 

 mer on the Cold Spring Beach. This beach 

 is a spit of sand, 2,000 feet long and 50 to 

 75 feet broad, running from the western 

 mainland into the harbor and ending in a 

 point that is being made several feet a year 

 through the cooperation of wave, tide and 

 a silt- transporting creek of fresh water. On 

 the outer harbor side is a broad, gradually 

 sloping, sandy and gravelly beach, covered 



