new tent is formed and even the chrysalis is often hung within the last one. The eggs which were laid late in May develop into butterflies during July. These in turn lay eggs for the second brood of caterpillars most of which develop into butterflies late in August or early in September, but some of which apparently remain in the chrysalis stage unchanged throughout the winter, and mature as butterflies about the middle of the following May. This is the explanation of the fact mentioned at the beginning of this discussion that one can find late in spring and early in summer some butterflies which seem worn and frayed while others seem perfectly fresh. They are all the progeny of the midsummer brood of the previous summer, but some of them have been living as full-grown butterflies through eight long months of tempestuous weather, while others have just been disclosed from the protecting walls of the chrysalis. The world-wide distribution of this butterfly is shown in the statement that it occurs throughout Europe, and in North America from Newfoundland to Cuba and Guatemala. It is a safe guess that it is found in practically all localities where nettles grow. It is not alone the association between a butterfly caterpillar and its host plant which has been brought about during the long ages through which one generation has been succeeding another, but there have been also many developments of similar associations between the caterpillars and their parasitic enemies. The Red Admiral is a good example of such a development. During its long growth as a species it has been exposed to attack by vast numbers of tiny foes which live at the expense of other insects. Several of these foes have found in the bodies of the caterpillars good opportunities for growth, so that now the Red Admiral, as a species, has to reckon with many enemies among these tiny parasites. The interaction between caterpillar host and uninvited parasitic guest has much to do with the great irregularity in the numbers of the butterflies. It is simply another example of that complicated struggle for existence, by means of which nature keeps ever a fairly even balance of her myriad forces. =The Painted Beauty= _Vanessa huntera_ One of the most interesting phases of the study of butterflies is to learn how often they take advantage in their life-history of any peculiarity of the food plant which has a protective value. The Painted Beauty is an excellent illustration of this. The caterpillar feeds upon the leaves of the common Everlasting or Gnaphalium. This is an abundant and widely distributed plant, found along roadsides and in fields and pastures. It is notable for the woolly covering on stems, leaves, and flowers--this dry, hairy surface being so evident that the flowers will apparently continue in blossom when they have dried, hence its common name Everlasting or, as the French call a similar flower, Immortelle. (_See plate, page 161._)