344 THE ZOOLOGIST. 



Stair's grounds in Wigtonshire there were collected the day 

 after the storm the corpses of upwards of five hundred Books.* 

 Cyclones in the Pacific islands have tended to the disappearance 

 of some land birds. Mr. W. W. Gill, a South Sea missionary, 

 once well known to anthropologists, writes : " Some years ago, 

 for three successive seasons, cyclones devastated some of the 

 islands of this group (Rarotonga). Consequently the 'Kakirori ' 

 (a bird larger than a Sparrow, with bright brown plumage), two 

 species of which were once common, especially in the neighbour- 

 hood of the sea, was (it was believed) exterminated." t 



With all allowances, however, it cannot be denied that by 

 purely natural causes we can trace in our own time very much 

 destruction in animal life, destruction slowly, surely and fre- 

 quently leading to extinction. Just as we find in nature pro- 

 cesses which make for the survival of the fittest ; or, again, the 

 perpetuation of new varietal forms that arise in a suitable 

 environment, so we see other agencies tending to the utter 

 disappearance of species which have reached their zenith in 

 evolutionary adaptability. We may well study the death as well 

 as the origin of species. We are apt to only observe the devices 

 in nature by which many species survive, and often ignore the 

 constant natural phenomena which doom so many species to 

 destruction. The species, like the individual, has its limit in 

 time, I and may be said to only endure on nature's sufferance. 

 Estimating these natural calamities in the past by the observa- 

 tion of those occurring in the present, the extermination of so 

 many "missing links" is not a weakness, but a proof in the 

 conception of evolution, the net result of natural causation. 



[In ' Nature ' for August 31st (p. 434) an onslaught has 

 appeared in the form of an anonymous paragraph on our first 

 contribution on this subject. It is stated that " the article is 



* ' Memories of the Months,' p. 71. 



f ' Jottings from the Pacific,' pp. 127-8. 



I Prof. GL H. Darwin, in his recent Presidential Address to the British 

 Association at Cape Town, remarked : "The degree of persistence or perma- 

 nence of a species, of a configuration of matter, or of a State, depends on the 

 perfection of its adaptation to its surrounding conditions. If we trace the 

 history of a State, we find the degree of its stability gradually changing, 

 slowly rising to a maximum and then slowly declining." 



