HAIRS ETC. 
ii5 
standing armies of fighting ants. Such plants are said to be myrmeco- 
philous (see Acacia, Cecropia, &c.). In this connection mention maybe 
made of the honey-drev so common on leaves (see Acer, Pithecolobium, 
&c.), and of the domalia or little dwellings inhabited by mites, usually 
constructed of hairs, or sometimes in little hollows or grooves of the leaf 
(see Fraxinus, Anamirta). 
Resin-passages are large canal-like intercellular spaces in the tissues of 
certain plants, e.g. Coniferae. Into them the plant secretes resin ; this 
appears to be a waste- product, though it may have an incidental value 
in protecting the wood from decay, or in other ways. 
Oil-cavities containing oils of various sorts, are frequent in various 
plants, especially in the leaves, where they show as translucent dots when 
held up to the light. They occur in Rutaceae, Guttiferae, &c. 
Glands are organs secreting fluids upon the surface of a plant (or 
sometimes internally). Water-pores and nectaries may be included under 
this head, and other glands secrete oils, &c. 
8 
2 
