Contents. xxxiii 



VII. 



Phyktic Development of the Markings of the Sphingida. Summary 

 and Conclusion, p. 370. 



The oldest Sphingida were devoid of marking, 370. Longi- 

 tudinal stripes the oldest form of marking, 371. Oblique striping, 

 373. Spot markings, 375. The first and second elements of 

 marking are mutually exclusive, but not the first and third, or the 

 second and third, 377. Results with reference to the origin of 

 markings; picture of their origin and gradual complication, 380. 

 General results; rejection of a phyletic vital force, 389. 



II. 



ON PHYLETIC PARALLELISM IN METAMORPHIC 



SPECIES. 



Introduction, p. 390. 



I. 

 Larva and Imago vary in Structure independently of each other, p. 401. 



Dimorphism of one stage only, 402. Independent variability of 

 the stages (heterochronic variability), 403. Constancy and varia- 

 bility are not inherent properties of certain forms of marking, 407. 

 Heterochronic variability is not explained by assuming a phyletic 

 vital force, 410. Rarity of greater variability in pupae. Greater 

 variability more common among caterpillars than among the 

 imagines. Causes of this phenomenon, 412. Apparent independent 

 variability of the single larval stages. Waves of variability, 416. 

 Saturnia Carpini an instance of secondary variability, 419. Causes 

 of the exact correlation between the larval stages and its absence 

 between the larva and imago, 429. 



II. 



Does the Form-relationship of the Larva coincide with that of the 

 Imago? p. 432. 



Family groups, 432. Families frequently completely congruent 

 435. Exception offered by the NymphalidcB, 435. In transitional 

 families the larvae also show intermediate forms, 441. Genera ; 

 almost completely congruent ; the Nymphalideous genera can be 

 based on the structure of the larvae, 444. So also can certain sub- 

 genera, as Vanessa, 445. Incongruence in Pterogon, 450. Species; 

 in congruence very common ; ,5". Ocellatus and Populi, 451. Species 



