II. 



An Evolutionist in East Africa. 



IT was the late Richard Jefferies, I think, who said that one of the 

 greatest charms of Gilbert White was that he had no theory : 

 he was not full, while he observed, of evolution, degeneration, and 

 the like. Yet under the present circumstances, it is hardly possible 

 to observe at all without ultimately testing the bearing of some of 

 one's observations on the problems that constantly agitate biology, 

 and during my recent short stay in East Africa I came across some 

 facts which seemed to me worthy of record in this connection. 



Shakespeare has observed "how use doth breed a habit in a 

 man " ; and certain observations I was enabled to make during 

 my voyage out would seem to suggest that it has a similar effect 

 upon lower bipeds. When arriving on board, the ship's ducks 

 looked miserable enough to give rise to a proverb ; they were unclean, 

 and had not yet accommodated themselves to the resting-place 

 afforded by the raised barred floor of their coop. Their squalor 

 disappeared by washing pretty frequently ; and before the end of 

 the voyage, I noticed that when they were let loose on deck after 

 this operation several of them, being so used by this time to perching, 

 selected anything handy, like a rope or a pipe, as a standing-place. 

 On reaching Zanzibar, I had a further instance of the versatility 

 of the mallard. Domesticated here, in a climate unnatural to it, 

 and where almost all the water accessible is extremely salt, this bird 

 has adopted terrestrial habits, and runs actively about on the mud 

 of a tidal swamp under a tropical sun at mid-day, retreating from the 

 water instead of taking refuge in it when approached. Even on the 

 sandy ground among the huts where there was no sea-water, these 

 ducks appeared comfortable and healthy enough, so that it is quite 

 possible that Anas hoschas will supplant the Muscovy duck {Cairina 

 moscliata), the usual domestic duck on this coast, which is naturally 

 less aquatic and a tropical bird. What modification may take place 

 in consequence of this change of habit should be an interesting 

 question. All that can be said at present is that the Zanzibar 

 mallard seems, if anything, slighter and more erect than the European 

 domestic duck, and that the males were, in the first week in August, 

 mostly in full plumage in Zanzibar, while at home at that time one 

 might vainly seek in fen or farmyard for a drake in complete 



