48 



knowledge. 



February, 1913. 



a moment the use of the peculiar pattern on the 



underside of the hind wing. The butterfly is 



settled on an umbel of wild chervil and anyone who 



wants a specimen of an 



Orange Tip has only to 



wait in a lane full of that 



plant and he will soon 



find one coming along, if 



it be May or June, though 



he may look in vain for 



one in the adjoining 



fields. 



The resemblance is so 

 complete that the butter- 

 fly in the midst of the 

 umbel can hardly be 

 discovered at all, and if 

 the photograph could 

 have been done in colours, 

 the concealment would 

 only have been more 

 completely shown ; the 

 white parts of the wing 

 representing the flowers, 

 and the green parts 

 representing the stalks, 

 involucres and other 

 green parts of the plant 

 as well as the background 

 of grass or hedge in the 

 distance. The conspicu- 

 ousness of the specimen 

 whose wings are not 

 drawn together proves 

 the point to perfection. 



Now the pattern (we 

 might call it the design) 

 so completely conceals 

 the resting Orange Tip is, 

 it will be seen, continued 

 at the tip of the fore wing 

 and this continuation of 

 the pattern is precisely 

 outlined by the very curve 

 which the end of the hind 

 wing makes. The}' fit 

 exactly ! But the orange 

 spot is completely con- 

 cealed. 



But there is more than 

 this, for it will be observed 

 that the front margin and 

 even the thin, sharp edge 

 of the fore wings (this 

 edge being often some- 

 what rounded) have mark- 

 ings of the same type, so 

 that, looked at ;';/ front, 

 the protective resem- 

 blance to the flower is 

 continued, in place of a 

 white line which would 



otherwise appear and be 

 Nature's details in this m 

 But there is yet even 



1. Large Cabbage White. 



2. South European Brimstone. 



3. Foreign Species. 



49. 



4. Small Copper. 



5. Foreign Species. 



6. Foreign Orange Tip. 



on the hind wing which the curves fitting so truly 



Figure 50. 



1 & 4. Green-veined White. 6. Painted Lady. 



2. Small Cabbage White. 7. Pearl-bordered Fritillary. 



3. Silver-washed Fritillary. 8 &99. Grayling. 

 5. Orange Tip. 10. Small Heath. 



dangerous — so minute are 

 atter. 



more. It will be seen on 

 examination that the 

 pattern on the tip of the 

 fore wing is somewhat 

 run into lines (as may be 

 seen in Figure 50, 

 number 5). This repeats 

 a tendency to the same 

 thing at the margin of 

 the hind w ing : and it 

 thus imitates in connec- 

 tion with the background 

 of green, and just at the 

 right place, the appear- 

 ance which the edges of 

 the umbel present. 



The completeness and 

 exactness of the continu- 

 ation of the pattern are 

 even more clearly shown 

 in the butterfly Figure 49, 

 number 6, a foreign 

 relative, I think, of our 

 Orange Tip. In this the 

 imitation of the pattern 

 on the hind wings is 

 much more exact, as will 

 be easily seen. 



The economy of Nature 

 is wonderfully illustrated 

 in these cases, since there 

 is precisely as much of 

 the needed pattern on the 

 fore wings and no more — 

 — of the hind wing and of 

 the fore wing design. 



Just the same sort of 

 pattern and its repetition 

 arc seen in the " Bath 

 White," Figure 48. 



A brief review of the 

 illustrations will suffici- 

 ently demonstrate the use 

 of this arrangement of 

 colour and markings. 



Figure 49, number 1, 

 and Figure 50, number 2, 

 show the large and small 

 Cabbage Whites. In 

 both the greenish-yellow 

 of the hind wing is 

 repeated at the tip of 

 the fore wing. The 

 colour is close to that of 

 the cabbage flower, but 

 it more closely still 

 resembles that of a dead 

 piece of cabbage leaf, 

 which, when faded, 

 takes exactly this colour. 



