THE CANADIAN ENTOMOLOGIST 63 



while other species make a similar exit and leave a portion of the 

 epidermis over the opening, there is no apparent design in the matter. So 

 the most gentle push will swing this portal from within, and, unfortunately, 

 a similar pressure will answer from without, a fact soon discovered by the 

 vulgar herd. But maritima has never had any experience with the outside 

 world, and soon its handiwork is destroyed by the scores of stragglers that 

 are ever seeking the seclusion afforded by such a commodious chamber, and 

 a perfect door is rarely opened by the moth for which it was intended. 

 Conditions which make maritima especially favourable for observation are 

 directly traceable to the food-plant, and it is a pleasure to conceive we can 

 now see it at work in a manner that prevailed primitively. In Helianthus 

 giganteus we meet a plant which flourishes many years from its root-clump 

 without change, sending up rugged stems, often a dozen or more, to the 

 height of eight feet, each succeeding year. It is one of those strong, 

 coarse weeds that easily work out their salvation in the competition with 

 their neighbours, and is naturally well disseminated. While a plant of the 

 open, it attains greatest perfection in those semi-swampy conditions that 

 prevail where the fresh-water streams of long ago have met the arms of the 

 sea and deposited at tide-water level the rich humus and peat formation 

 that have been the accumulations of centuries. The north shore of Long 

 Island Sound presents innumerable instances of this nature, and from their 

 underlying peaty deposits and the slightly saline character, a certain 

 portion of these areas is immune from the advance of an arboreal growth, 

 and the primitive forest never claimed them. Here the flora is naturally 

 somewhat unique, and the insect life, of course, conforms to it. Our 

 Papaipema species have not been slow to avail themselves of such con- 

 ditions, an evidence of their aristocratic proclivities, and flourish here 

 according to a more or less prearranged schedule. Furthest out where 

 the salt-meadow conditions prevail and where the spring tides overflow 

 the soil twice monthly, grows a luxuriant fringe of Solidago sempervirens, 

 its roots deep in the meadow muck and containing P. duovata. Immedi- 

 ately inside this Helianthus giganteus begins to appear where a handful 

 of upland soil serves to temper the muck, and maritima will be found in 

 the outermost vanguards. From the moment upland proper begins there 

 is a revel of those rank plants which perennially hold their own ; the 

 coarse Aster umbellatus tenanted by P. impecuniosa, Lilium superbum a 

 choice tit-bit for cataphracta, Cicuta maculata containing marginidens, 

 and Thalictrum polygamum with its ever-present frigida. As we come to 



