chap, xil] COMPLEX EYE-SPOTS. 299 



on right side, while on the left the same spot is reduced as shewn 

 in the figure, the centre being of the colour normally constituting 

 the third band. 



In connexion with the above cases it should be mentioned that 

 in another species, Morpho sulkowskii, one of the more transparent 

 species, the spots a 1 , a,, and g x are all normally present. The spot 

 c is however sometimes absent in this species. In M. psyche the 

 spot c is normally absent, though present in one specimen examined. 



Complex ocelli. 



Besides the simpler ocelli there are other forms of ocelli of 

 more complex structure, having two or more centres around which 

 the coloured zones are disposed without an accurate symmetr} 7 . 

 Such ocelli may be seen in Vanessa io or in Junonia, and it is 

 noticeable that they are no less variable than the simpler forms. 

 The following examples may be given. 



Vanessa io. Looking at the eye-spot on the fore wing of the 

 Peacock-butterfly one can readily see that it is not a structure of 

 the same nature as the other ocelli that have been already con- 

 sidered. The eye-spot of the hind wing does not materially differ 

 from other eye-spots, being essentially a black spot surrounded by 

 a pale band and containing an irregular and incomplete centre of 

 blue. The eye of the fore wing on the contrary is not actually 

 made up of concentric markings but is quite exceptional, being 

 formed of a combination of patches of different colours. But 

 whether the eye of the fore wing is a true ocellus or not it is 

 nevertheless certain that its formation mav vary with that of the 

 eye of the hind wing, as the following examples testify. 



451. Specimen, British; reared from a larva in captivity, having all the 

 eye-spots deficient (Fig. 82). On the fore wings the series of white 

 spots along the margin (on the creases) are present. The three which 

 lie within the field of the normal eye-spot are longer than usual. The 

 costal black mark is extended so as to cover the greater part of the 



Fig. 82. Vanessa io, the Peacock butterfly, having all the four eye-spots 

 deficient (No. 451). (From Newman.) 



