98 MY LIFE [Chap. 



both zoological and palaeontological discovery were advancing 

 with great rapidity, while new and improved classifications of 

 some of the great classes and orders were in constant progress. 

 But though many of the details given in these volumes would 

 now require alteration, there is no reason to believe that the 

 great features of the work and general principles established 

 by it will require any important modification. Its most 

 severe critics are our American cousins, who, possessing a 

 " region " of their own, have been able to explore it very 

 rapidly ; while from several references made to it, I think it is 

 appreciated on the European continent more than it is in our 

 own country. 



While this work was in progress I wrote a considerable 

 number of reviews and articles, published my book on 

 "Miracles and Modern Spiritualism," and wrote the article 

 " Acclimatization " for the " Encyclopaedia Britannica." 



In 1876 I sold the house at Grays and removed to Dorking, 

 where we lived two years. But finding the climate relaxing, 

 we moved next to Croydon, chiefly in order to send our 

 children first to a kindergarten, and then to a high school, 

 and remained there till May, 1881. 



During this period, besides my usual reviews and articles, 

 I prepared my address as president of the Biological Section 

 of the British Association at Glasgow, wrote the article on 

 " Distribution — Zoology" for the "Encyclopaedia Britannica," 

 and prepared a volume on "Tropical Nature," which was pub- 

 lished in 1878. In this work I gave a general sketch of the 

 climate, vegetation, and animal life of the equatorial zone of 

 the tropics from my own observations in both hemispheres. 

 The chief novelty was, I think, in the chapter on " climate," 

 in which I endeavoured to show the exact causes which pro- 

 duced the great difference between the uniform climate of 

 the equatorial zone, and, say, June and July in England, 

 although at that time we receive actually more of the light 

 and heat of the sun than does Java in June or Trinidad in 

 December. Yet these places have then a mean temperature 

 very much higher than ours. It contained also a chapter on 



