1899] THE EVOLUTION OF IMMUNITY 103 



natural selection, and (6) the living of a healthy life, along with which 

 may be included the hygienic devices which make for the elimination 

 of microbes. Our author believes that carefully discriminated statistics 

 show a decrease in the number of severe and fatal attacks. The cry 

 " Back to a more natural life " is, he says, an instinctive one, which is 

 becoming more and more general, and it is the voice of reason. It is 

 plain, however, that there is another side to the question, which Hay- 

 craft emphasised in his " Darwinism and Eace Progress " — If the race 

 eliminates its own eliminators (the disease germs) which have at least 

 helped to make it what it is, if it becomes no longer susceptible to 

 their eliminative action, what selective agents — even more discrimi- 

 nating, let us hope — are to take their place ? But how the human 

 race is to get along when bacteria have ceased from troubling is not a 

 pressing problem, and Dr. Eeibmayr does not raise it in his " Wort zur 

 Beruhigung." 



Photographic Process Colour Printing. 



The publication of the well-known series of coloured photographic 

 process views of scenery made it evident that similar processes would 

 be soon employed for the illustration of zoological books, and we have 

 just seen what we believe to be the first application of this method of 

 illustration to birds. The pictures in question appear in " Birds that 

 Hunt and are Hunted," by Neltje Blanchan, which was published in 

 1898 by Doubleday and M'Clure, of New York. Forty quarto plates 

 of birds, with 360 pages of text, are issued at the low price of two 

 dollars. The illustrations leave little to be desired, and some of them 

 are perfectly lifelike, notably the Pintail Duck and the Teal, while the 

 coloration of the Passenger Pigeon is perfect. These plates are pro- 

 duced by the Nature Study Publishing Company of Chicago, and are 

 well worthy the attention of those who publish similar books in this 

 country. All the exquisite pencilling of the feathers is shown in a 

 way far superior to that produced by lithography, while the cost is 

 infinitesimal as compared with that of an artist. We are sorry that 

 the lithographic artist will have to go, but we are glad that birds can 

 at last be presented with an accuracy that renders their identification 

 easy. 



A Noble Gift. 



The Annual lieport of the Curator of the Museum of Comparative 

 Zoology at Harvard College has just come to hand. It is impossible 

 to scan its pages without feelings of sadness and of admiration. For 

 the last time in his official capacity as Director, Prof. Alexander 

 Agassiz, the worthy son of an illustrious sire, renders account of his 

 stewardship. This alone would make for sadness were it not lightened 



