IN MODERN SCIENCE. 



207 



to 



through many generations of animals becomes 

 too intricate to be credible. Instinct must have 

 originated in a perfect condition, and with the 

 organism and its environment already estab- 

 lished. I may borrow here an apposite illus- 

 tration from recent papers on the unity of 

 nature by the Duke of Argyll, which deserve 

 careful study by any one who values common- 

 sense views of this subject. The example 

 which I select is that of the action of a young 

 merganser in its effort to elude pursuit : 



" On a secluded lake in one of the Hebrides, 

 I observed a dun-diver, or female of the red- 

 breasted merganser {Mergus serrator), with 

 her brood^ of young ducklings. On giving 

 chase in the boat we soon found that the 

 young, although not above a fortnight old, 

 had such extraordinary powers of swimming and 

 diving that it was almost impossible to capture 

 them. The distance they went under v»rater, 

 and the unexpected places in which they 

 emerged, baffled all our efforts for a consider- 

 able time. At last one of the brood made 

 for the shore, with the object of hiding among 

 the grass and heather which fringed the margin 

 of the lake. We pursued it as closely as we 

 could ; but when the little bird gained the 



