BY THE EEV. CANON TRISTKA.M;. 19 



the water is open, but sometimes finding Mmself in a blind chan- 

 nel, yet nevertheless pushing onwards, and not ashamed to con- 

 fess that his vision and his directions have been often at fault. 

 Now the greatness of Darwin does not depend upon his theories, 

 which even his warmest admirers are ready to admit are often a 

 superstructure built on an uncertain basis of doubtfully interpre- 

 ted facts, but because he has developed a new system of observa- 

 tion and study, which has revolutionized biology by directing 

 attention to the general relations and the environments of plants 

 and animals. He has led us to ask why closely allied species 

 are seldom found together, why extinct animals are larger than 

 living ones, why flowers are so wonderfully varied, why male 

 birds are often so much more brilliant than their mates, and in- 

 numerable questions on the relations and variations of all crea- 

 tion. Perhaps that, which many years ago first directed Mr. 

 Darwin's thoughts towards his theory, when he was exploring the 

 Gralapagos Islands, is the most important of all in its bearing on 

 the records of creation, I mean the modifications and changes of 

 insular faunas and floras. To the ornithologist, the botanist, or the 

 student of the invertebrates, there is no subject more interesting 

 or attractive than the biology of oceanic islands. This is in fact 

 the living geological record of life on the globe. We may almost 

 fancy we can read its chronology as we mark the greater or less 

 divergence of island life from that of the nearest continents. 

 Mauritius and the Seychelles tell us on the one hand of their 

 connection both with India and Africa, and on the other of their 

 immense antiquity, by the differentiation of every form of life. 

 Again the comparison tells us how much longer Mauritius had 

 been isolated from Rodriguez than from Bourbon by the greater 

 divergence of their types. All these problems of insular and 

 geographical distribution in c'onnection with the development of 

 species have come into prominence within the last twenty years. 

 Now considering how utter was our ignorance twenty years ago 

 as to the probable mode of the development and modification of 

 species under varying conditions, we can hardly be surprised if 

 scientific men have been tempted to rush into the other extreme, 

 and to claim presumptuously an almost complete knowledge 



