90 Dr. F. A. Dixey on the 2)hylof/enetic 



Moreover with reference to the study of these mark- 

 ings in especial, it must not be forgotten that the 

 investigator is deprived of the assistance usually afforded 

 to similar enquiries from the side of embryology, for the 

 characters in question spring as it were at once into 

 perfect being at a definite stage in the life of the 

 individual ; they have, so to speak, no growth, no 

 embryology.* Nevertheless, in spite of these limita- 

 tions, it would seem worth while to examine the evidence 

 available from this source with as much accuracy as 

 possible, to see how far it will go towards indicating 

 lines of probable development, and to determine the 

 direction in which such lines appear to lead. The 

 conclusions so reached will no doubt need to be checked 

 and corrected by evidence derived from other quarters, 

 but ought, nevertheless, to be allowed their due weight 

 in any settlement that endeavours to be final. 



The amount of material available for the construction 

 of a phylogeny of the Nymphalidce as a whole has 

 received a notable addition in an elaborate memoir by 

 W. Miiller (' Siidamerikanische Nymphalidenraupen '), 

 published in the 'Zoologische Jahrbiicher,' Bd. I., 1886, 

 pp. 417 — 678. His conclusions, however, as there given, 

 extend in the main only to groups of higher importance 

 than genera ; and the sole data on which they rest are 

 the facts of the larval and pupal ontogeny and habits, 

 the perfect form being left out of account altogether. 



In comparing the evidence of kinship derived from 

 the study of immature stages with that obtainable from 

 adult forms, it must not be forgotten that in cases such 

 as the present, in which the immature stages have a 

 separate and independent existence of their own, the 

 conditions amid which the earlier periods of life are 

 passed will have their own special influence upon the 

 larval form and development, without necessarily pro- 

 ducing any corresponding effect upon the form ulti- 

 mately assumed ; and that consequently the affinities 

 disclosed by the larva do not always exactly correspond 

 with those indicated by the perfect organism. This 

 point, to which attention had in some degree been 



'■= A possible exception to this general statement may exist in the 

 pigmentation of the wings of certain pupae. This point needs 

 further investigation. See below, pp. 125 — 128. 



