302 
CA UCALIS 
Caucalis Linn. (incl. Torilis Adans). Umbelliferae (8). 18 sp. N. 
Hemisph., S. Afr. 5 in Brit, (hedge-parsley, &c.). 
Cayaponia Silva Manso. Cucurbitaceae (in). 70 sp. trop. Am., 1 Afr. 
Ceanothus Linn. Rhamnaceae. 40 sp. Am., often cultivated as orna- 
mental shrubs. 
Cecropia Linn. Moraceae (in). 30 — 40 sp. trop. Am. Trees of rapid 
growth, with very light wood, used for floats, &c. The infl. is a very 
complex cyme (see Bot. Centr. 57, p. 6). C. peltata L. is the trumpet 
tree, so called from the use made of its hollow stems by the Uaupes 
Indians (Wallace, Amaz. ch. xn). The hollows are inhabited by 
fierce ants ( Azteca sp.) which rush out if the tree be shaken, and attack 
the intruder. Schimper has made a thorough investigation of this 
symbiosis (or living together for mutual benefit) of plant and animal, 
showing that there is here a true case of myrmecophily as in Acacia 
sphaerocephala (q.v.). These ants protect the C. from the formidable 
leaf-cutter ants. Several adaptations are to be seen in the tree. 
The intemodes are hollow but do not communicate directly with the 
air. Near the top of each however is a thin place in the wall. A 
gravid female ant burrows through this and brings up her brood 
inside the stem. The base of the leaf-stalk is swollen and bears food 
bodies (cf. Acacia) on the lower side, upon which the ants feed. 
New ones form as the old ones are eaten. Several other sp. 
show similar features. A very interesting point, that goes to show 
the true adaptive nature of these phenomena, is that in one sp. the 
stem is covered with wax which prevents the leaf-cutting ants from 
climbing up, and in this sp. there are neither food-bodies nor the thin 
places in the walls of the internodes. Cecropia trees that are not 
inhabited by ants fall an easy prey to the leaf-cutters. Miiller once 
observed a tree stripped by them whilst still inhabited by Azteca; 
investigation showed that it was because the cold had rendered the 
latter incapable of fighting. 
Cedrela P. Br. Meliaceae. 20 sp. trop. Many yield valuable timber, 
e.g. C. odorata L., the West Indian Cedar, used in making cigar- 
boxes, &c., C. Toona Roxb., the Cedar- wood of S. India, C. australis 
F. von Muell, the Australian red Cedar, &c. 
Cedronella Riv. Labiatae(vi. 3). 9 sp. N. Am., Japan, Canaries. 
Cedrus (Tourn.) Mill. Coniferae (Arauc. 1 b; see C. for genus charac- 
ters). 3 sp., C. Libani Barrel. (Cedar of Lebanon), C. atlantica 
Manetti (Atlantic Cedar; Algeria) and C. Deodar a Loud. (Deodar; 
Himalaya); all are probably varieties of one sp. whose distribution has 
become discontinuous (p. 146). They are handsome evergreen trees 
(often planted for ornament in Brit.) with needle leaves and both long 
and short shoots ; the latter may continue to grow for several years 
and may even develope into long shoots. Firs, solitary, in the 
position of short shoots. The cone ripens in 2 — 3 years. The wood 
is very durable and is highly valued for building, &c. 
