EVOLUTION. 
Gen. /Sub. 61 
On modification of species : Hybrids, &c. ; Lataste (294). 
Proposed evolution-experiments, mainly as regards hybridisation ; 
Beiila (31). 
Third edition of Der Bau des Menschen ; Wiedersiieim (574). 
Spontaneous generation, as discussed by Henry Baker and Joblot ; 
Cazeneuve (80). 
b. Variation. 
Materials for the study of variation : Marshalling of facts as to 
meristic variation. Discontinuity of variation : “The discontinuity of 
which species is an expression has its origin, not in the environment, nor 
in any phenomenon of adaptation, but in the intrinsic nature of 
organisms themselves, manifested in the original discontinuity of varia- 
tion.” “The existence of new forms, having from their first beginning 
more or less of the kiud of perfection that we associate with normality, 
is a fact that disposes, once and for all, of the attempt to explain all 
perfection and definiteness of form as the work of selection.” Variation 
in domestication : Refutation of the common belief that variation is 
greater in amount in domesticated animals than in wild forms. 
Reversion : Criticism of the hypothesis of reversion, which is con- 
veniently, but without sufficient warrant, appealed to to explain the 
sudden occurrence of large and regular variations. Definiteness of 
variation : Bateson’s induction discloses a greater definiteness of 
variation that is suggested by the words “ fortuitous,” “ indefinite,” 
“in every part of the organism,” commonly used by Darwinians to 
describe variations. The suggestion is made that this definiteness is an 
expression of the physical limitations put upon variation by the condi- 
tions of organic stability ; Bateson (24). 
Definite lines of variation ; Osborn (398). 
Variation in flat-fishes : colours (of a brill) on dorsal and ventral 
borders have, so far as three spots are concerned, varied similarly and 
simultaneously, producing a result nearly symmetrical about the hori- 
zontal axis. Another case of plaice with posterior half of “ blind ” side 
fully pigmented and with thirteen spots, nine of which coincide with 
spots on the upper side ; Bateson (25). 
Reference to previously expressed conclusions as to discontinuous vari- 
ation. Evidence of leaps from one position of stability to another ; 
Galton (176). 
Discontinuous colour-variation ; Cockerell (96). 
The phrase organic stability “ used to express the well-substantiated 
fact that a race does sometimes abruptly produce individuals who have a 
distinctly different typical centre.” “ The inference or connotation is 
that no variation can establish itself unless it be of the character of a 
sport, that is, by a leap from one position of organic stability to another, 
or as we may phrase it, through ‘ transilient ’ variation.” “ If there be 
