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A difficulty that confronts the student with regard to periodicals 

 is how to find among the mass of material the items that relate to any- 

 particular insect. True, each volume has its index, but to consult the 

 indexes of 40 volumes each of three or four periodicals is no small under- 

 taking, particularly when the generic names change so often. Fortunately 

 in many families and genera of butterflies and moths, monographic papers 

 have been published giving full references to the bibliography with name 

 of author, volume and page and date of publication. Most catalogues 

 give reference to the original description, so our labours are lightened to 

 some extent. 



From some of these periodicals we may learn about the mourning 

 cloak butterfly: that it is to be found not only throughout North America 

 from Dawson City to Texas, but also in Europe and through Asia to 

 Japan; particulars are given of parasitic insects which keep it from be- 

 coming a serious pest to the trees; we also learn that the butterfly can 

 produce an audible scratchy sound by rubbing file-like roughened parts 

 of the wings together, and much other interesting information. But 

 there are many things the books won't tell us, for example, why the few 

 specimens that are taken in England never have the borders of the wings 

 a bright yellow, but dirty white. Neither do they tell us why we find 

 the early spring butterflies getting more and more tattered and torn as 

 April goes by, but early in June specimens in much better condition are 

 seen. The only book to go to is the Book of Nature, the free common 

 property of all, written in a language we can all understand, if w^e will 

 but study its pages and turn them over one at a time to find more and 

 more to lead one on. 



We are tempted out into the fields again a little later in the season, 

 say about Victoria Day, and the clouded sulphur butterfly, philodice, 

 is on the wing actively searching for clover on which the female lays her 

 eggs for the caterpillars to feed upon. The white imported cabbage but- 

 terfly, rapae, hovers about the roadsides and gardens ready to attack our 

 cabbage plants, lettuce, mignonette and nasturtiums; while the native 

 green-veined white, oleracea, is more apt to be seen in clearings in the 

 woods. Here and there also we see the black swallow-tail butterfly, as- 

 terias, sailing about over fields and gardens particularly where there are 

 parsley, carrot or any umbelliferous plants that its handsome caterpillar 

 feeds upon. These four butterflies belong to a different family from the 

 mourning cloak, and are to be found in our books a long way from our 

 previous acquaintances, and we are perhaps tempted to study the classi- 

 fication a little to see what distinguishes them. All insects have six legs 



