No. 1.] 
ORGANIC VARIATION. 
285 
TABLE XII. — Continued. 

SPECIES. 
. f. salicicolus (Ridgw.) 
. alicize Baird 
. a. bicknelli (Ridgw.) 
. ustulatus (Nutt.) 
u. swainsonii (Cab.) 
. aonalaschkez Gmel.: 
. a. auduboni (Baird) 
. a. pallasii (Cab.) 
. iliacus Linn. 
Merula migratoria (Linn.) 
H84888 48H 
M. m. propinqua Ridgw. 
M. confinis (Baird) 
M. flavirostris Swains. 
M. graysoni Ridgw. 
Hesperocichla nzvia (Gmel.) 
Cyanecula suecica (Linn.) 
C. wolfii Brehm 
Saxicola cenanthe (Linn.) 
Sialia sialis (Linn.) 
S. s. azurea (Baird) 
S. s. guatemale Ridgw. 
S. mexicana Swains. 
S. arctoa (Swains.) 
+O OF OHO 0303400 

eK 







MIGRATION. 
BREEDING AREA. 
M. Rocky Mts. 
E. M. Labr. to Arctic coast. 
E. M. Catskill Mts. to Nova 
Scotia. 
E. M. Pacific coast n. to Sitka. 
Ei. Me. NA na of Unis. 
M. coast from Cal. to Kodiak. 
M. Rocky Mts. 
M. n. e. U. S. northward. 
M. n. Eurasia. 
M.e. N. A. n. to Hudson Bay 
& Alaska. 
M. w. Us S.n. to) B. C.7e..to 
Rocky Mts. 
Ress Uacalt 
R. w. & s. Mex. 
R. Tres Marias Is. 
M.w. N.A.n.to Behring Strait. 
M. n. Eurasia. 
M. c. Europe. 
M. n. portions of N. Hemis- 
phere. 
M. e. U. S. w. to Rocky Mts. 
R. highlands of Mex. & s. Ariz. 
R. highlands of Honduras & 
Guatemala. 
Ri ws Ue Sin. toy be Cees ato 
Rocky Mts. 
M. Rocky Mts. n. to Gt. Slave 
Lake. 


The following table (XIII) represents the percentage of 
species and subspecies examined, of fourteen families, evincing 
variation of at least 1.5% in two dimensions. 
Only such species 
and subspecies enter into the computation for which Ridgway’s 
measurements express variation in at least three of the five 
dimensions ; and the percentages have been deduced separately 
for non-migratory, migratory, and extensively migratory species 
and subspecies. 
