296 ANIMAL INTELLIGENCE. 



huge nest for the whole society. L. Valiant's account has been 

 fully confirmed by other travellers. He says : ' I observed on the 

 way a tree with an enormous nest of these birds, which I have 

 called republicans; and as soon as I arrived at my camp I de- 

 spatched a few men with a waggon to bring it to me, that I might 

 open and examine the hive. When it arrived, I cut it in pieces 

 with a hatchet, and saw that the chief portion of the structure 

 consisted of a mass of Boshman's grass, without any mixture, 

 but so compact and firmly basketed together as to be impene- 

 trable to the rain. This is the commencement of the structure, 

 and each bird builds its particular nest under this canopy. But 

 the nests are formed only beneath the eaves, the upper surface 

 remaining void, without, however, being useless ; for as it has a 

 projecting rim, and is a little inclined, it serves to let the water 

 run off", and preserves each little dwelling from the rain. Figure 

 to yourself a huge irregular sloping roof, all the eaves of which 

 are covered with nests, crowded one against another, and you 

 will have a tolerably accurate idea of these singular edifices. 

 Each individual nest is three or four inches in diameter, which 

 is sufficient for the bird ; but, as they are all in contact with one 

 another around the eaves, they appear to the eye to form but 

 one building, and are distinguishable from each other only by a 

 little external aperture which serves as an entrance to the nest; 

 and even this is sometimes common to three different nests, one 

 of which is situated at the bottom and the other two at the 

 sides. This large nest, which was one of the most considerable 

 I had anywhere seen in the course of my journey, contained 

 320 inhabited cells, which, supposing a male and female to each, 

 would form a society of 640 individuals ; but as these birds are 

 polygamous, such a calculation would not be exact.' 



The following is quoted from Couch ( ' Illustrations of 

 Instinct,' p. 227 et seq.~) : 



Mr. Waterton says there is a peculiarity in the nidification 

 of the domestic swan too singular to be passed over without 

 notice. At the time it lays its first egg the nest which it has 

 prepared is of very moderate size ; but as incubation proceeds 

 we see it increase vastly in height and breadth. Every soft 

 material, such as pieces of grass and fragments of sedges, is laid 

 hold of by the sitting swan as they float within her reach, and 

 are added to the nest. This work of accumulation is performed 

 by her during the entire period of incubation, be the weather 

 wet or dry, settled or unsettled ; and it is perfectly astonishing 

 to see with what assiduity she plies her work of aggrandisement 



