1889-] 0?i Variation. 1077 
cestain amount of independence, yet subject to a general subordi- 
nation, so that, according to Haeckel and Schmidt, we are deal- 
ing neither with individuals nor colonies in the ordinary sense of 
the words. 
" As Schmidt well says : ' From the variability of all the charac- 
ters, our idea of an organism as a limited or centralized individual 
disappears in the sponges, and in place of an individual, or a col- 
ony, we find an organic mass, differentiated into organs, while the 
body, which feeds itself and propagates, is neither an individual 
nor a colony.' " 
We turn again for a few moments to the " Origin of Species " 
to show the recognized variability in a genus of plants. Darwin 
refers in considerable detail to the work of De Candolle upon the 
oaks of the whole world, pointing out his wealth of material, and 
the great care he took in the discrimination of species. He 
mentions that in this work De Candolle notes the many points of 
structure which vary, and " specifies above a dozen characters 
which may be found varying even on the same branch, some- 
times according to age and development, sometimes without any 
assignable reason." Though not regarded as of specific value, 
they are yet such as often enter into specific descriptions. The 
rank of species is given in this case only to forms which differ in 
" characters never varying on the same tree, and never found 
connected by intermediate states." De Candolle remarks : " They 
are mistaken who repeat that the greater part of our species are 
clearly limited, and that doubtful species are in a feeble minority. 
This seems to be true so long as a genus was imperfectly known, 
and its species were founded upon a few specimens, — that is to 
say, were provisional. Just as we come to know them better, 
intermediate forms flow in, and doubts as to specific forms aug- 
ment." He goes on to say, adds Darw^'in, " that it is the best- 
known species which present the greatest number of spontaneous 
varieties and sub-varieties. Thus Quercus robur has twenty-eight 
varieties, all of which excepting six are clustered round three 
sub-species." The forms connecting these are rare, and if they 
were to become extinct, "the three sub-species would hold 
exactly the same relation to each other as do the four or five 
