1891. ] Are Acquired Variations Inherited ? 199 
sent a plus-variation, in the other direction a minus-variation ; 
mediocrity is the state of rest or balance. When we examine 
any species in course of evolution in time and space we find, how- 
ever, that a mediocre character is a shifting quantity. An organ, 
for example, which is rapidly degenerating presents a certain 
“ mediocrity ” at one time and locality, and another “ mediocrity ” 
at a later time or another locality. There is, therefore, a clear dis- 
tinction between the above terms and the more general terms 
“ degeneration,” “balance,” and “ development,” which apply to 
characters which are either continuously static or in a downward 
or upward direction, not only in individuals but in whole species 
and larger divisions. Of course where regression ceases to exert 
its full gravitating force upon plus- or minus-variations, througha 
series of generations, development or degeneration respectively 
set in. 
Another source of confusion, which is inevitable in observation 
but not in theory, is the difficulty of distinguishing between 
“congenital” and “individual variations.” Weismann has 
marked the distinction by the useful terms “ blastogenic ” and 
“ somatogenic.” * Theoretically these congenital and acquired 
variations are quite distinct; but as some blastogenic variations 
do not manifest themselves until advanced life, it is extremely 
difficult in many cases to decide how far certain variations are 
really blastogenic and how far somatogenic in origin ; in other 
words, how far they are due to inherited predispositions and how 
far due to life habits.” , 
A war of words has recently been waging as to the meaning 
to be attached to such adjectives as “fortuitous,” “ chance,” 
“kaleidoscopic,” or “indefinite.” My understanding of these 
‘terms is that when we see characters fluctuating from mediocrity, 
in either the plus or minus direction, according to the ordinary 
laws of chance, we may describe them as in a state of indefinite 
variability; whereas, when they exhibit a tendency to fluctuate 
principally in one direction, we describe them as ina state of 
18 j. e., as arising from the germ-plasma and body respectively. 
1 In his review of Wallace's ‘‘ Darwinism” Lankester has pointed out this defect im 
some of Wallace's observations. Nature, 1889, p. 567. 
