TEE PROGRESS OF SCIENCE. 



95 



tion is not strictly proportional to 

 accelerating force and that kinetic 

 energy is not strictly proportional to 

 the square of the velocity of a moving 

 body. 



Up to the present time a very promi- 

 nent feature of physical science has 

 been the reduction of every kind of 

 phenomenon to mechanics. Tlie no- 

 tional elements out of which nearly 

 every theory is built up are essentially 

 mechanical in their nature, if one may 

 use the term mechanical in a broad 

 sense to signify all kinds of geometric- 

 al, kinematical and dynamical rela- 

 tions. The reason for this preponder- 

 ating role of mechanics is that, 

 hitherto at least, only those theories 

 are effectively useful which are built 

 up out of sensuous elements, and 

 nearly all our complicated sensations 

 refer to space relations as perceived 

 with the eye and to dynamic and space 

 relations as perceived by the sense of 

 touch and by the so-called muscular 

 sense. It is not likely that the trans- 

 fer of mechanics to an electromagnetic 

 foundation will greatly affect the pre- 

 ponderating role of concrete mechanics 

 in physical science. 



TENDENCIES IN ZOOLOGY. 

 Zoology also has its fashions. The 

 publication of the 'Origin of Species,' 

 by establishing a new standpoint and 

 new problems, led zoologists to an ever 

 minuter study of comparative morphol- 

 ogy, already made fashionable by the 

 work of Cuvier, Johannes Miiller and 

 Owen. On the discovery of the chordate 

 affinities of the Tunicates by Kowalew- 

 sky, in 1866, an impulse was given to 

 the investigation of comparative em- 

 bryology, in the hope of further infor- 

 mation, which, viewed in the light of 

 the biogenetic law, might add other 

 links to the phylogenetic chain. And 

 later, when the science of cytologj' came 

 into definite existence, the embry- 

 ologist, who at first was content to 

 carry his studies back only so far as 

 the gastrula, was incited to delve more 



deeply, and for a time cell-lineage be- 

 came the fashion, while, following 

 quickly in the footsteps of this, exper- 

 imental morphology became a vogue. 

 Not that this last was an entirely new 

 department of investigation, but rather 

 a revival under new conditions and 

 points of view of the methods of study 

 employed by Trembley and Spallanzani 

 whose experimental researches on 

 Hydra and the earthworm respectively 

 have reached the dignity of classics. 



The latest fashion, nature-study, as 

 it is called, is likewise a revival of 

 older methods. It is a rejuvenescence 

 of the natural history of the ancients, a 

 return to the methods of Gilbert White, 

 methods which, while they have never 

 failed to attract, have unfortunately 

 been sadly neglected of late by the pro- 

 fessional zoologist. The developments 

 of his subject have been towards ever- 

 increasing esoterism, until the stage 

 has now been reached when the laity 

 has lost touch with the professional 

 and fails to appreciate the results 

 which he elaborates in the privacy of 

 his laboratory, surrounded by his com- 

 plicated engines for cutting sections 

 and his multitudinous reagent bottles. 

 In so far as this new revival of natural 

 history methods may serve to bring 

 about again a rapprochement of the 

 amateur and the professional, it is to be 

 welcomed, and important additions to 

 our knowledge of the habits and in- 

 stincts of animals and the significance 

 of these may be expected when men, 

 specially trained in the methods of 

 biological investigation and thought, 

 turn their attention to these phe- 

 nomena. 



But the enthusiasm which usually 

 accompanies investigation along a new 

 line must not blind to the danger which 

 lurks beneath. The hope which lies in 

 the departure is that it will tend to 

 place the study of instincts and habits 

 on a scientific basis and yield scientific 

 results founded on careful and accurate 

 observations, that, in a word, it will 

 bring order into the chaos of observa- 



