413000 |++ 
22 BEI LI 72 le n= 
4 ++rr4+0000 
10000 p +++++sooeee 
g DEIEZIZ 22222 
8 0000000+44m++++++++B 850 PT“ 
7 00000000000+++44++++ +++0 000 0 E90 az 
6 0000000000060 000+4++4h4+++. +++ LITT IT) 2202 
5 00000000 0060000000+ + +++++++-+H +++ 000000000000 
4 0 00000 000000 0000 0000000 0000000|4++++++44+h+++4+++++B 00 
3 000 0000000060000000040000000000l000+++t+++h+++++++++4 + ++0000 0 
2 a srrrtrrrthrrrranne 
4000 Jooo0o0000 000000600000 00006 000000++H+++++++ ++ H+++20000 0 
feet 
500 0000000 0000000000000 00000000l0 00004 ++++H+++++t+ tt eeoS0000 Me 
0 EUR SAT LI U AR rt 
10 20 30 40 50 60 70 Species. 
Diagram No. III. 
Showing the numbers of Southern, Sonoran and Nearctic species which occur at 
the altitudes from O to 13000 feet. 
For instance at the level of 9000 feet oceurs 1 Southern, 6 Sonoran and 9 Nearetie 
species (cf. with Diagram No. I and with Lists A, B, C©). 
climate different from that of their respective home conditions. 
Taken as a whole, the Northerners are either hardier (indifferent 
