206 THE QUANTITATIVE METHOD IN BIOLOGY 



gradation. Comparison between the effects of Mendelian dis- 

 sociation, plasticity, gradation and individual development. 

 Example of segregation by gradation : the primordium downy 

 in the sheaths of the leaves of Holcus (p. 45). A similar 

 example is described in my paper on Mnium, p. 20, Remark IV. 



(2) § 49 (6) (p. 61) : Comparison of the curves of develop- 

 ment of several primordia according to the method followed 

 (§ 140, second example, and § 141) for the comparison of grada- 

 tion curves. 



(3) § 52 (fifth example, p. 68) : Influence of gradation on 

 certain properties of the leaves of Mosses. (See also my paper 

 on Mnium.) 



(4) § 71 (P- S6)  Any axis is a line of segmentation, differ- 

 entiation and gradation. Gradation in the erect branches of 

 Pseudochcete gracilis, in an egg of Spirogyra, in a hair. 



(5) § 79 (p- 96) * Alteration of a chess-board system by 

 gradation. 



(6) § 82 (p. 100): Gradation in a chess-board system in the 

 direction of the axes NS and EW ; complicated effects (Fig. 13, 

 p. lOl). 



(7) § ^3 (P- loi) : Continuous and discontinuous gradation 

 (differentiation). Antenna of Carabus. Epidermis of Allium 

 porrum. 



(8) § 84(p. 104) : Curvature of compound axes a consequence 

 of gradation. 



(9) § ^5 (P- 107)  Gradation a cause of disorder in biaxial 

 systems. 



