294 



MERISTIC VARIATION. 



[part I. 



be determined by the manner of stretching of the wing-membranes. 

 It must still be remembered that in the great majority of cases of 

 ocellar variation there is no change in the neuration. 



As to the function of ocellar markings nothing is known, and I 

 am not aware that any suggestion has been made which calls for 

 serious notice. 



Evidence as to Variation of Ooelli in Lepidoptera. 



General variability of ocelli. 



The following are chosen to illustrate the general variability of 

 ocelli in Satyridae. Any of the common forms, such as C. darns, 

 P. megaira, &c. shew similar variations. Generally speaking the 

 condition is bilaterally symmetrical, but somewhat asymmetrical 

 examples are not rare. 

 *443. Hipparchia tithonus : from some 80 specimens taken in one 





Fig. 76. Hipparchia tithonus <? , cases illustrating Variation in number of ocelli. 

 I. In f. w. the upper half of the large ocellus has a pupil, the lower has none : 

 in h. w. no ocellus. II. Both halves of large ocellus of f. w. have pupils, and the 

 h. w. has one ocellus. III. Pupils of large ocellus of f. w. are larger : h. w. has 

 two ocelli. IV. F. w. has a new ocellus and the large double ocellus is half- joined 

 to a second new ocellus. H. w. has two ocelli, one being placed otherwise than in 

 III. V. F. w. has two ocelli without pupils as well as the large double one. H. w. 

 has three ocelli. The wings of the other side corresponded neai'ly though not 

 accurately. II. is the most frequent form. 



(This figure was drawn with especial care from the specimens by Mr Edwin 

 Wilson.) 



