cause, as well as to the preceding, that I am led to attribute the extraordinary multiplication of so many species during the three last summers, which were separated by severe winters.  Last winter was mild, and there is therefore no reason to expect that there will be another multiplication; but I hope that the harm done by such a season will be slight.  It is the progressive multiplication of the destroyers, joined to the correlative disappearance of the victims caused by a series of temperate seasons, that is to be feared.

In support of the proposition that I maintain, I may mention still another fact.  While this district (Pembroke, Wales) is relatively poor in species whose larvae feed and hibernate in the open air a few species of Noctuellae, whose larvae live buried in the earth, are always abundant.  The country is relatively rich in spices of Tortrix, which develop and hibernate in the stalks or roots of plants.  It is also worthy of remark that very few of our species seem to be incapable of enduring a severe winter.—­C.G.  Barret, in Science et Nature.

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SILK WORM EGGS.

Prof.  C.V.  Riley, entomologist, announces that the Department of Agriculture, Washington, will purchase during the coming summer such quantities of silk worm eggs as may be deemed necessary for the distribution that it is proposed to make for the season of 1886.  So far as found practicable, the eggs will be purchased of American producers.  There are certain precautions, however, that must be taken to insure purchase.  Eggs of improved races only (preferably of the French or Italian Yellow Races) will be bought, and the producer should send one or two samples of pierced cocoons with the eggs.  In addition to this the producer must conform to certain rules to be hereafter explained, so that an examination may be made that will serve to show the degree of purity of the eggs.  No silk culturist should use his crop for the production of eggs unless the worms have shown, until they began the spinning of their cocoons, every sign of perfect, robust health.  Any indication of the disease called flacherie, from which the worms so often die after the fourth moult and turn black from putrefaction, or of any other disease from which silk worms suffer, should be considered as ample reason for not using the cocoons for the purpose in question.  They should, on the other hand, be sold for the filature.  If the worms have all the indications of health until the spinning period, then the cocoons may be used for the production of eggs.  The following brief instructions will prove of service to those who which to secure sound eggs: 

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