76 Qen.Sub. 
I. GENERAL SUBJECTS. 
(4). — Inheritance of acquired characters may not be directly demon- 
strable, nor physiologically explicable, but indirect evidence of it is 
cumulative ; Haacke (273). — In acquired characters there is still an 
hereditable factor which renders it impossible to draw any satisfactory 
distinction between them and non-acquired characters : Bennett (35). — 
Suggestion that organ-arrangement, colour-marking, &c., is rather indi- 
vidually acquired in the course of metabolism than hereditarily fixed ; 
Graf (255). — Formation of a structural character, a fifth toe on a guinea 
pig, and its inheritance ; Saint-Loup (612, 613). — General considera- 
tions on h8teromorphic heredity ; Hanot (283). 
9. Evolution. 
a. General. 
Delage (145), Dorman (155). — A primer of evolution ; Clodd(113). — 
First principles of evolution ; Nicati (489). — The Darwinism of Darwin, 
and of the post- Darwinian schools; Romanes (586). — The method of 
organio evolution ; Wallace (727). — “ Artung und Entartung ” ; Arndt 
(10). — Lord Salisbury’s addross on evolution; Spencer (664). — Prosont 
problems of organio evolution ; Cope (116). — The present phase of the 
theory of evolution ; Thomson (691). — Mathematical contributions to the 
theory of evolution. Skew variation in homogeneous material ; Pearson 
(514). — What is a tendency ? Bennett (35).— Utility of specific 
characters ; Romanes (586). — “ The questions raised by the Darwinian 
hypothesis are purely statistical, and the statistical method is the only one 
at present obvious, by which that hypothesis can be experimentally 
checked ; Weldon (742). — Darwinism and race progress ; Haycraft 
(289). — Teratogenic experiments ; Fj£r^ (190). — Collection to illustrate 
evolution ; Carpenter (93). — Palaeontology and the biogenetic law ; 
von Zittel (775). 
For question as to “ Epigenesis or Evolution ” in development, see 
under Embryology , p. 69. 
b. Variation. 
Classification of variations : (a) fluctuating, individual or continuous 
variation, modifying the relative number of the different kinds of 
pangenes ; (b) specific variation, in which the division of pangenes is 
qualitatively diverse ; de Tries (719, 720). — I. Primary, or somatogenic, 
due to external influences (environment and functional) on the body. ii. 
Secondary or germinal, arising either (a) apart from amphimixis and 
selection, or (b) in association with these ; Rohde (583). — Classification 
and analysis of variations ; Eigenmann (172, 173). 
Variation, exposition of ; Brandt (65). — Causes of variation : Varia- 
tions arise by the blending of molecular dynamical systems of different 
initial potential strengths, by the conjugation of sex-cells (reciprocal 
