1915] BAILEY & SHEPARD—SANIO’S LAWS 67 
The writers recently had occasion to test the validity of SANroO’s 
first two laws in connection with an investigation undertaken in the 
endeavor to secure a simple method for segregating long and short 
“fibers” in the manufacture of raw wood pulp. The following 
North American conifers were studied: Pinus Strobus L., P. palus- 
tris Mill., Picea rubens Sarg., Tsuga canadensis Carr., and Abies 
concolor Lindl. and Gord. Chips of wood were removed from the 
specimens and were macerated by the use of a 5 per cent solution 
of equal parts of chromic and nitric acid. The tracheids were 
separated after maceration by being shaken with water and glass 
beads, insuring minimum breakage. They were then kept in a 
mixture of 95 per cent alcohol and chloroform to prevent softening. 
The measurements were made with a micrometer eyepiece, 50 
measurements from each chip. The results obtained are shown in 
the following tables: 
EFFECT OF AGE ON THE LENGTH OF TRACHEIDS 
TABLE I 
Pinus Strobus, 120 ANNUAL RINGS, CROSS-SECTION I FOOT FROM GROUND 
TR scrtcneeeees|| TRACHEID LENGTHS —MILLIMETERS 
ANNUAL RING ] ANNUAL RING 
Max Min. Av. | | Max. Min. Av. 
BO) 3.35 1.60 2.65 he aD 5.10 2.65 4597 
Xe 3.65 2.45 3.02 OOivi seas 4.60 2.50 3-79 
40... ee, 4.80 2.55 3.64 LOO. 2s fy i 4.65 2.50 3.85 
$9... 266.4. 4.20 2.35 3.30 RIO ey 4.45 3.20 3-91 
Ma eae bons + 4.65 2.45 3.47 T20.20;-5551 5.40 3-45 20 
Ls Ra or | 4.80 2.65 3.52 
TABLE II 
Abies concolor, 80 ANNUAL RINGS, ELEVATION OF CROSS-SECTION UNKNOWN 
| TRACHEID LENGTHS—MILLIMETERS ‘ TRACHEID LENGTHS—MILLIMETERS 
ANNUAL RING ANNUAL RING 
Max. Min. Av. Max. Min. Av. 
i ee 3.50 4.20 2.75 SO. ae ee) 5.45 3.30 4-45 
BOs can s's 2.40 490 OO. ss vessee 5.48 3-55 4.64 
Beer. ere: 4.90 2.50 3.65 ie Raglip ee at 6.30 3.50 5.02 
sed dese 5.65 2.15 es a) Rega ean 6.45 3.85 5.20 
