CocKBURN-HooD. — Xeir Zealand a Poxt-ijlacial (.'fittre nf Creation. 13 



elaboration of new species, by the "aimless action of Natural Selection," 

 necessitates the granting of tlikty times the number of millions of years 

 physical considerations render it possible to allow, as Dr. Tait states the 

 question, the difficulty of the position will not be lessened by Herr Haeckel's 

 bold assertion, that " we have not a single rational ground for conceiving 

 the time requisite to be limited in any way." 



This writer, although he deems very slow progress to have been the 

 rule, leaves his readers to believe in the possibility of exceptions to it. 

 Notwithstanding the small advances made during the recent period in any 

 line of life (how the cats, the dogs, and the pigeons of the days of the 

 earliest Pharoahs remain represented but by pure cats and dogs and 

 pigeons still, not one attempt at j)assing beyond the limit of its class 

 having been made by any of these creatures, whose development has 

 received such attention and studied assistance from man), they are not to be 

 daunted by the proposition that in new centres of creation, such as New 

 Zealand, the derivative process was by some means marvellously hastened 

 in its accomplishment. 



Recurring periods of heat and cold extending simultaneously over the 

 greater pai't of the world, may be convenient agents to call into requisition 

 for the purpose of explaining the disappearance of many forms of organic 

 life. The vanishing of others for a time, and their return to the same 

 localities, displacing very different ones that in the interim had flourished 

 there, is, no doubt, due to such cause. But had these cycles been repeated 

 more frequently than even according to the views of Mr. Croll they have 

 been — views much more within our grasp than the consideration of pro- 

 cesses requiring ceons paralyzing to- the minds of most men who attempt to 

 dwell upon them — they would not account for many of the events which we 

 know have taken place in the history of animal life. 



Ten thousand or twenty thousand years may be deemed by evolutionists 

 generally, periods altogether too short for the accomplishment of any of the 

 processes of divergence and development necessary to the establishment of 

 species, for which millions have been asked ; but much could be done 

 during such a vast lapse of years in the way of perfecting various families 

 and the extinction of others. The recurring joeriods of the reign of frost 

 over particular areas in alternate hemispheres, which have evidently taken 

 place, would cause no violent changes, advancing as they must have done 

 with slow enough steps to afford ample opportunity for the migration of 

 existing forms of life to suitable situations, so long as any such remained 

 for them to migrate to, which during this Glacial Epoch of Professor 

 Haeckel were certainly reduced to a minimum. 



There was no ice-sheet enveloping their ancient haunts, which destroyed 



