2 THE POPULAR SCIENCE MONTHLY. 



ravages of insects. Now, however, it is the pivot on which the doc- 

 trine of man's origin hinges. The worlds themselves are too old to 

 study, though tbe spectroscope reveals the existence of celestial pro- 

 toplasm as their physical basis. The rocks are too rigid and the time 

 too immense to come within tbe compass of our minds, but the living 

 facts of evolution are with us to-day in these graceful forms and their 

 constant changes, while the records more or less preserved in past times 

 give us a clew to things hinted at in the earlier changes of present ex- 

 isting forms. It seems, therefore, at the present time, that a review 

 of the work accomplished by American students for the doctrines of 

 natural selection might be acceptable for several reasons, and first 

 among them might be mentioned the fact that thus far no general re- 

 view of the kind has been made; and, secondly, that with few excep- 

 tions all the general works upon the subject are from English or Ger- 

 man sources, and filled with the results of work done there oftentimes 

 to the exclusion of work done elsewhere. The oft-repeated examples in 

 support of the derivative theory belong to Europe. The public are fa- 

 miliar with these facts only, and come naturally to believe that these 

 examples alone exist, and from their remoteness do not carry the 

 weight of equally or perhaps more suggestive facts which lie concealed 

 in the technical publication's of our own societies. A review of the 

 work accomplished by American students bearing upon the doctrine 

 of descent must of necessity be brief. Even a review of a moiety of 

 the work is beyond the limits of an address of this nature. And for 

 obvious reasons I must needs here restrict it to one branch of biology, 

 namely, zoology. For material, the scientific publications of the coun- 

 try have been scanned, and an attempt has been made to bring to- 

 gether the more prominent facts bearing upon natural selection. In 

 this review the zoological science of the country presents itself in two 

 distinct periods : The first period, embracing as to time-limits the 

 greatest portion, may be recognized as embracing the lowest stages of 

 the science ; it included among others a class of men who busied them- 

 selves in taking an inventory of the animals of the. country, an im- 

 portant and necessary work to be compared to that of the hewers and 

 diggers who first settle a new country, but in their work demanding 

 no deep knowledge or breadth of view. And so the work to be done 

 in tabulating the animals has more often been done by specialists who 

 neither knew nor cared to know the facts lying beyond the limits of 

 their studies ; a work often prompted by the same spirit that one sees 

 among children in the collection of birds'-eggs and postage-stamps. 

 The workers in this class were compared by Agassiz to those who 

 make the brick and shape the stone for the edifice, an indispensable 

 work, but with it was raised not the edifice but an almost insuperable 

 barrier against the acceptance of views more in accordance with rea- 

 son and common-sense. So thoroughly interwoven with this work 

 were certain conceptions believed to be infallible, that overpowering 



