No. 1.] ORGANIC VARIATION. 287 
The following four tables (KX V—XVIII) give respectively the 
percentage of those species and subspecies examined, in each 
family enumerated, showing an amount of individual variation 
of at least 2% in the particular dimension (culmen, wing, tarsus, 
or whole length). Only such families are computed, for which 
Ridgway’s data express individual variation in the particular 
dimension for at least ten species. 
TABLE XV. 
Comparative tabulation of percentage of species examined, with variation in the 
length of the cu/men of at least 2%. 




+ ocd 
og 
Famuy. | 222 | 0% | 5% | 1% | 10% | 20% | 30% 50% 
A % 
Vireonidz 18 side 
Tyrannidz 43 13.9 
Mniotiltidz 14 14.2 
Icteridz 31 16.1 
Corvidee 35 16.6 
Turdide 24 16.6 
Falconidz 64 17.1 
Fringillidz 109 17.4 
Troglodytide| 47 
Picidze 42 
Rallidz 16 
Paridz 10 
TasBLeE XVI. 
Comparative tabulation of percentage of species examined, with variation in the 
length of the wig of at least 2%. 


5.29 
oO 
FamILy. E 22 0% 20% | 30% | 40% 50% 
als 
Vireonide 26 ° 
Mniotiltida 71 fo) 
Paridz 26 fo) 
Turdide 32 fe) 
Icteridz 43 fo) 
Corvide 42 fe) 
Tyrannidee 63 fo) 
Fringillidze 181 
Troglodytide | 49 
Picide 48 
Falconidz 89 
Rallidz 16 






