VARIABILITY. 
125 
<b. 
Ap. 
Xiv. 
°f two ].- 
wliich insensibly graduate into each other, 
th e s • ’ s h’ght differences between all the members of 
ll(J s pecies, and more strongly-marked deviations 
' v itli r .° Ccur °fly occasionally. These latter are rare 
^ len transmitted to succeeding generations. 3 
c !tae 8 lr ’^ ess j it may be worth while to give the few 
^el <l!l j 1 °' a1 l ’T? chiefly to colour (simple albinism and 
lj ifcls ia a state of nature, and it is very doubtful 
ei they have often been preserved through selec- 
c °llf. et Sm ^eing excluded), which I have been able to 
of y is well known rarely to admit the existence 
8p 6e jg lttle Sj for he esteems very slight differences as 
^ Il0v ' r he states 33 that near Bogota certain hum- 
! Wi f j e; j ll .^ s belonging to the genus Cynanthus are 
f tOm ln to two or three races or varieties, which differ 
c 1 other in the colouring of the tail, — “ some 
6 
S, ttM are ftoquently regarded a3 distinct species. Of the latter, 
tia to be , vs that only ten ore really doubtful, and that the other fifty 
be a a lln j te d with their nearest allies ; hut this shews that there 
Iff* 8 ' It • 0n ® < t° ra t>le amount of variation with some of our European 
Au, e S R * so an unsettled point with naturalists, whether several 
'a 2 < **»esp oa )y n ^‘ rt ' s ought to be ranked as specifically distinct from 
^ _ ] 
| * 1 - C!iii c . f j riU l an| I strongly-marked deviations of structure, deserving 
, v ;<jtion, a n ??i 1Stl ' l,s ® es ’ ouuld seldom be preserved through, natural 
cin| dep eu V ” at *' 10 preservation of even highly-bendioial variations 
ta the; i n a certain extent on chance. I had also fully appre- 
o 'Pounce of mere individual differences, and this led i 
‘Orj,,.: ll,l S European species. 
C( I, duit" 01 ®l- iei '* t!s i' fifth edit, 18011, p. 104. I had always per* 
vj<; ^ strongly on the importance of that unconscious form of 
0- !l ) iH(H V j i j Uatl ’ w hich follows from the preservation of the most 
th. V th<, „i Uu * 8 each breed, without any intention on his part to 
l*.,'/ korti, n a ^ clra8 °I the breed. But until I read an able article in 
(March, 1867, p. 2S9, el seq.), which has 
of ia Review 
^ Use to me than any other Review, I did not see how 
33 , 0t stro n °i aS " ere a S a i us t the preservation of variations, whether 
* I niton. ^ y pronounced, occurring only in single individuals. 
Uct - to the Trochilida;,' p. 102. 
