ON THE PINES OF AUSTRALIA. 167 
gradually becoming less and less, and no steps are being 
taken for its propagation. 
Transverse tests of specimens of C. glauca of standard 
size (38 in. by 3 in. by 3 in.) made by Mr. James Nangle, at 
the Technical College, gave the following results:— 
le 196 III. 
B=8:02" B=2:968" B=8-005" 
aS {p =3:03"” D=3:025”" D=38-02" 
L=36” i367 Nij=36" 
Size of specimen 
Area of cross section, square inches 9°15 8:998 9°06 
Breaking load in tbs. per square inch 4850 4.290 3050 
Modulus of rupture in tbs. per sq. in. 9448 8529 6010 
Modulus of elasticity in tbs. per sq. in. 1,016,470 1,183,160 875,675 
Rate of load in tbs. per minute ... 485 451 210 
Three smaller pieces 12 in. by 1 in. by 1 in. gave the 
following results:—1. broke at 900 tbs, deflection °37 in. ; 
2. broke at 850 ths., deflection °28 in.; 3. broke at 690 ibs., 
deflection °20 in. 
(b) Histology.—Very little if anything appears to have 
been done to investigate the anatomical structure of the 
timber of Australian Callitris, or at any rate our researches 
through the Conifer literature at our disposal revealed 
little or nothing. The data now given should therefore 
prove of interest in the future study of this genus. Phylo- 
genetically the results are of some value, for a connecting 
link so to speak was found to exist between these living 
Callitris and the fossil pine woods of North America, in that 
the tracheids of the xylem contain a similar substance; a 
circumstance that will be touched upon in a later paper. 
A transverse section of the timber viewed under a low 
magnification as in Fig. 16, shows a more or less irregu- 
larity in the diameter and thickness of the tracheidal walls 
in the several medullary rows. This figure is interesting 
in that there is quite an absence in the picture of resin’ in 
+ Although the term resin is used for the dark substance in tracheids 
of the xylem, a name generally applied to this body, yet in view of the 
chemical constituents present, and the absence of resin in the timber, it 
is very doubtful if it is correct to call it a resin. 
