CEMENTERS. 95 
scribed; and it must be confessed that it was a work 
truly admirable, considering the instruments of the 
little mechanics.”* 

CHAPTER IX. 
CEMENTERS, 
One of the old classifications of birds ranged them 
in three divisions, the first comprehending those 
which muddled in the dust; the second, those which 
Washed in the water; and the third, those which did 
both. A division, something upon the same princi« 
ple, with regard to the building of nests, would com- 
prehend, in the first class, birds which used no sali- 
vary cement; in the second, those which did; and 
in the third, those which used it only in a portion, 
not the whole of their structures, In no circum- 
stance of nest-building has there been more error 
promulgated in books of natural history than with 
respect to this cement, few naturalists seeming to 
be aware of its existence ; but finding nests so neat- 
ly compacted, and their parts adhering firmly to 
one another as well as to walls and boughs of trees, 
authors think it requisite to name some adhesive 
material by which this is accomplished ; and, when 
there is no clay in the edifice, spiders’ web is the 
substance generally fixed upon. We do not indeed 
deny that both the webs of spiders and of the social 
caterpillars are partly employed by some birds; 
but this is by no means an occurrence common to 
all the small, neatly-built nests of our song-birds and 
some others, as we are taught in books to believe. 
As this very point involves one of the most curious 
discussions connected with the subject of nests, we 
* Oiseaux d’Afrique, iii., 77, é&c. 
