Ee a a ee 
1884.] Zoölogy. 543 
be considered in its major and readily recognizable manifestations 
as a resultant of artificial selection, being a concomitant upon 
notable unstability of forms so produced; as it rarely, if ever, 
occurs in appreciable degrees in organisms which have been unin- 
fluenced by man’s fostering care. 
Because nature changes and develops her products so slowly 
from any of the requirements that preceded it; and the ten- 
cy is rather to gradually depart still further from the ancestral 
branch than to revert back towards it. 
and thus enable us, as has been done in the case of artificially 
exaggerated variability, to reason by analogy of its existence 
mg natural conditions and of its function and mode of action 
ere 
For while it is probably one of the most frequent and power- 
ve i 
confined within comparatively narrow limits, and 
nds rather upon continuous action, as with its collaborators, 
direct heredity and variability, each separate coéfficient, o 
which there may be several acting synchronously in the same 
individual, unites in producing evenly blending results with its 
nws, and is bounded by the first fixed varietal characteristics 
sree J in the immediate ancestral line. 
a domesticated varieties the nearest strongly fixed point, not- 
or ading the number of changes they may have undergone, 
€ length of time they have existed as such, is generally the 
lferal stock, which had become stable by reason of the 
This i7. of natural selection. 
be 18 especially manifest in the case of color for reasons to 
ü ‘ea further on. In nature its manifestations are so slight 
of escape the most critical observations, necessarily, from want 
or Conditions for study without trammeling and thereby 
ot ifying to a greater or less extent the species brought under 
Sre e characters produced by artificial selection, as 
mesticated organisms, become stable only in a 
their degree and by lesser causes, namely, on account of 
tinned ness to man, and are preserved only through his con- 
Mental peonision. That they would be, and are, as a rule, detri- 
cvident °° the Organisms if left to themselves, is, of course, self- 
character 0n quently, they can never become so potent as 
tics derived through the agency of natural selection, 
