xxxii Contents. 



IV. 



Biological Value of Colour, p. 289. 



General prevalence of protective colouring among caterpillars, 289. 

 Polymorphic adaptive colouring in C. Elpenor, C. Porcellus, P. 

 QLnothera, D. Vespertilio, D. Galii, >. Livornica, D. Hippophaes, 

 295. Habit of concealment primary; its causes, 298. Polymor- 

 phism does not here depend upon contemporaneous but upon 

 successive double adaptation; displacement of the old by a new 

 adaptation; proof in the cases of D. Hippophaes, D. Galii, D. 

 Vespertilio, M. Stellatarum, C. Elpenor, and S. Convolvuli, 300. 



V. 



Biological Value of special Markings, p 308. 



Four chief forms of marking among Sphingidcz, 309. Complete 

 absence of marking among small caterpillars and among those living 

 in obscurity, 310. Longitudinal stripes among grass caterpillars, 

 312. Oblique striping. Coloured edges are the shadows of leaf 

 ribs, 317. Eye-spots and ring-spots. Definition, 326 : Eye-spots not 

 originally signs of distastefulness, 328; they are means of alarm, 

 329; experiments with birds, 330; possibility of a later change of 

 function in eye-spots, 334. Ring-spots. Are they signs of dis- 

 tastefulness? Are there caterpillars which are edible and which 

 possess bright colours ? 335; experiments with lizards, 336. In D. 

 Galii, D. Euphorbia, D. Dahlii and D. Mauritania the ring-spots 

 are probably signs of distastefulness, 341. In D. Niccza they are 

 perhaps also means of exciting terror, 342. The primary ring-spot 

 in D. Hippophaes is a means of protection, 344. Subordinate 

 markings. Reticulation, 347. The dorsal spots of C. Elpenor and 

 C. Porcellus, 348. The lateral dots of S. Convolvuli, 348. Origi- 

 nation of subordinate markings by the blending of inherited but 

 useless markings with new ones, 349. 



VI. 



Objections to a Phyletic Vital Force, p. 352. 



Independent origination of ring-spots in species of the genus 

 Deilephila, 352. Possible genealogy of this genus, 358. Inde- 

 pendent origination of red spots in several species of Smerinthus, 

 360. Functional change in the elements of marking, 365. Colour 

 change in the course of the ontogeny, 367. 



