860 THE KVOLl'TlUN TlllOOKY 



we can prove that many ha-vi' already .siicriimlied in the strn^'^'le 

 with man, and we antieipnle tlie externiinatidii ol' otluM\s. l-iiit tlie 

 reason M'hy tliey are no ivadily exteiminaled obviously lien in tiie fact 

 thattliey have surrendered tlie ad\jiiita,n'e j;i\en to tlieni hy their bird- 

 nature, by adaptini;- theuitclves to terrestrial lil'e, and (hat (liey are 

 not able to regain it, at least not in the .sliort time that is at- their 

 disposal if they are to be saved from exteriiiinatiou. The be.st 

 example of this is the Dodo (D/iIuk liir/iltiK). 'VWm remarkable-look- 

 ing bird, of about the size of a, swan, lived in flocks njion the island of 

 IMauritius until about the end of the sex'ontecnth et'utury. \l had 

 small wings with short (juills which were useless for High!.. As it 

 could neither escape by flight nor through the watei-, and eotdd only 

 move clumsily and awkwardly upon kind with its sliort legs and 

 heavy body, it was hopelessly doomed as soon as a stronger enemy 

 made his appearance. It fell a victim to the sadors who lirst huided 

 on the island and clubbed it with sticks in huge numhora. Uiilril tliat 

 e\ent it was without doubt excellently adapted to life on thai^ fertile 

 island, I'or on a ^■oleanic island in the middle of the ocean there were 

 no large enemies, and it was therefon^ not de])(uulent on the powei' of 

 flight for safety, and could pick up al)undant food from the ground. 

 But when man suddenly ap])eai-ed on tlio scene and began to jier- 

 secute it, it was not the 'senile rigidity' of its organization that 

 prevented it from making use of its wings again ; it was the slowness 

 of variation and c()nse(|ueu(ly of selection, which is conniion to all 

 species, which im]i(!lled it to extinction. The same fate will ]iroba,bly 

 overtake the fCiwi of New Zealand {A plcvjij' aiit^I'ml'iK) in the neai' 

 future, for though it has so far escaped the ari-ows of tliu aborigines, 

 it is not likely in its wingless condition to be able to hold out long 

 against European guns, unlei-s ekjse times and ]ii'eser\ed forests ai-e 

 instituted for it, as they have been for our chamois. 



Even sadder From tlie biologist's point of view than such (ixter- 

 mination of individual species thi'ough the \aiidalism and greed of dui- 

 own race is the disturbance of whole societies of a.nimaJs and plants 

 by man that is going on or has been accomplished on most of the 

 oceanic islands, and we must bridly notices these cases whiliMve are (heal- 

 ing with the deoack'iice of species. I refer to the crowding out of the 

 usually endemic animal and plant popula.tioii on such islands through 

 cultivation. The first step in this woi'k of ' cultivation ' is always tlio 

 cutting down of the forests which for thousands ol' yeai's lia,v(^ elotjied 

 these islands as with a mantle of grcjen, have regulated their rainfall, 

 secured their fcM'tility, and allowed a medley of indigenous aninuds, 

 usually peculiar to the spot, to arise. We have already siioken of 



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