OF INTELLIGENCE AND INSTINCT. 89 



made exceedingly comfortable. Others show very great in- 



:lty in concealing their nests from the eyes of their ene- 



. or in placing them beyond their reach. There is a small 



bird in the East Indies, the tailor bird (Sylvia sutoria), which 



works wool or cotton into threads, with its feet and beak, and 



t to sow together the leaves of trees for its nest. 



197. The nest of the fiery hang-bird (Icterus Baltimore), 

 dangling from the extremity of some slender, inaccessible 

 .-. is familiar to all. The beautiful nest of the humming- 

 bird, seated on a mossy bough, and itself coated with lichen, 

 and lined with the softest down from the cotton-grass or the 

 mullein leaf, is calculated equally for comfort and for es- 

 caping observation. An East Indian bird, (Ploceus Philippi- 

 nus,) not only exhibits wonderful devices in the construction, 

 security, and comfort of its nest, but displays a still further 

 advance towards intelligence. The nest is built at the tips of 

 long pendulous twigs, usually hanging over the water. It is 

 composed of grass, in such a manner as to form a complete 

 thatch. The entrance is through a long tube running down- 

 wards from the edge of the nest; and its lower end is so 

 loosely woven, that any serpent or squirrel attempting to enter 

 the aperture, would detach the fibres, and fall to the ground. 

 The male, however, who has no occasion for such protection, 

 builds his thatched dome similar to that of the female, and by 

 its side ; but simply makes a perch across the base of the 

 dome, without the nest-pouch or tube. 



198. But it is among insects that this instinctive solicitude 

 for the welfare of the progeny is every where exhibited in the 

 most striking manner. The bees and wasps not only prepare 

 cells for each of their eggs, but take care, before closing the 

 cells, to deposit in each of them something appropriate for the 

 nourishment of the future young. 



199. It is by the dictate of instinct, also, that vast num- 

 bers of animals of the same species associate, at certain periods 

 of the year, for migration from one region to another ; as the 

 swallows and passenger pigeons, which are sometimes met 

 with in countless flocks. 



200. Other animals live naturally in large societies, and 

 labour in common. This is the case with the ants and the 

 bees. Among the latter, even the kind of labour for each 

 member of the community is determined beforehand, by in- 



