A DAY WITH TUE SWALLOW-TAIL. 387 



pillars, whicli yet are supplied with no apparatus for driving 

 them away. This organ, whatever purpose it may subserve, 

 gives forth a very strong odour, much resembling that of 

 fennel, and so powerful that even in the open air it can be 

 perceived at some distance. 



The colour of this splendid Butterfly is almost entirely 

 yellow and black. On the lower wings, however, there is a row 

 of six cloudy blue spots, sprinkled with yellow dots, and at the 

 anal angle of each lower wing is a large red spot with a slight 

 blue crescent on the upper part. This Butterfly was once spread 

 over a considerable part of England, but now seems to be 

 restricted to the marshy parts of Cambridge, Huntingdon, and 

 Norfolk. It has been taken in many other places, but I believe 

 that in all those instances it was not native to the place, but 

 had been artiticially introduced. I once saw a specimen in a field 

 by the Cherwell, close to Oxford, and chased it for some time, 

 but unsuccessfully. Whether or not this was an introduced 

 specimen, I have no means of ascertaining. 



I was never fortunate enough to have a day's Machaon- 

 hunting, but my friend, Mr. D. J. French, has sent me an 

 account of a very successful day's hunt : — 



'Saturday, July 10, 1871, will always be a red-letter day in 

 my annals of natural history. 



' My brother and I drove off, amid the rain-like mist, along 

 one of those everlastingly flat Cambridge roads, till we sighted 

 the whitewashed front of the old public, with the conspicuous 

 sign of " Five miles from anywhere." In a few minutes more 

 we were over the ferry, and stepping off to the fens with some- 

 what hopeful feelings, for the sun was peeping out. The ditch 

 was soon cleared by the help of the jumping-pole, kept at the 

 aforesaid inn for the use of entomologists. My brother was 

 over first, and before I could follow a hearty shout informed me 

 that a Swallow-tail was captured. In less than three minutes, 

 at 1.5 P.M., three hm-rahs rang through the fens, as I beheld, 

 for the first time in my life, a self-captured Papilio Machaon 

 within my net. Oh, 'twas a pleasant sight to see ! 



' The next two hours were exciting ones indeed, for no sooner 

 had I pinned an insect than another was seen. Although 

 ready to drop through the heavy chase just completed, off we 

 dashed, disturbing from their nests and passing unheeded 



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