24 BURNING OFF THE GEASS. Chap. I. 



immense crops of tall grass, here a nuisance, however valuable 

 elsewhere. A white cloud was often observed to rest on 

 the head of the column, as if a current of hot damp air 

 was sent up by the heat of the flames and its moisture was 

 condensed at the top. Bain did not follow, though theorists 

 have imagined that in such cases it ought. 



Large game, buffaloes, and zebras, were abundant abreast 

 the island, but no men could be seen. On the mainland, 

 over on the right bank of the river, we were amused by the 

 eccentric gyrations and evolutions of flocks of small seed- 

 eating birds, who in then- flight wheeled into compact 

 columns with such military precision as to give us the 

 impression that they must be guided by a leader, and 

 all directed by the same signal. Several other kinds of 

 small birds now go in flocks, and among others the large 

 Senegal swallow. The presence of this bird, being clearly in 

 a state of migration from the north, while the common 

 swallow of the country, and the brown kite are away beyond 

 the equator, leads to the conjecture that there may be a 

 double migration, namely, of birds from torrid climates to the 

 more temperate, as this now is, as well as from severe 

 winters to sunny regions ; but this could not be verified by 

 such birds of passage as ourselves. 



On reaching Mazaro, the mouth of a narrow creek which 

 in floods communicates with the Quillimane river, we found 

 that the Portuguese were at war with a half-caste named 

 Mariano alias Matakenya, from whom they had generally 

 fled, and who, having built a stockade near the mouth of 

 the Shire, owned all the country between that river and 

 Mazaro. Mariano was best known by his native name Mata- 

 kenya, which in their tongue means " trembling," or quiver- 

 ing as trees do in a storm. He was a keen slave-hunter, and 



