feeding vermin does not add to their numbers, in the same or any future season, for insect life is so strangely dependent on certain conditions of temperature, &c, that if the season is not favourable to a particular kind it will be scarce, no matter how plentiful it may have been in a previous year.  In the case of the Turnip Fly, feeding is frequently the cheapest and surest way of saving the crop.  It is customary with Dahlia-growers, and, indeed, with the growers of florists’ flowers generally, to sow Lettuces where the flowers are to be planted, for so long as Lettuces are on the spot Slugs and Snails will prefer them to other food.  As the Lettuces themselves serve the purpose of traps, the Snails and Slugs congregated about them may, towards evening, be caught and destroyed.

In using a mixture for the first time, it is advisable to try it on one plant only, and that, of course, the worst in the collection affected.  If the preparation is too strong, the truth will be declared by the state of the plant within twenty-four hours; thus a little caution may prevent a great loss.  Another good rule is to employ the several remedies in a rather weak state until experience has been gained, for not only has the strength of the medicine to be considered, but the management of the patient before and after it is administered.  It is above all things important to be thorough in the cleansing of plants, because they succumb rapidly to the attacks of insects, and should be effectually and promptly cleaned or consigned to the fire.  If left in a foul state they spread the infection to all around.  In the space at our command it is only possible to notice a few of the garden pests, and we begin with one of the most frequent and troublesome of plant foes.

==Aphis== in some form or other is the most persistent and perplexing of plant pests.  The Green Fly is the enemy of the softer kinds of vegetation, and the Blue and the Black Fly are common plagues of the Peach-house and the orchard.  The tender body of the Aphis is instantly affected by conditions unfavourable to its life, and it is therefore easily killed; but its marvellous power of reproduction renders its extinction impossible, for in every instance a few escape, and very soon re-establish their race.  Two methods for the destruction of Aphis are in vogue.  One is fumigation by tobacco, either pure or in some of the numerous preparations offered, including several popular insecticides which have nicotine as a basis.  These are both clean and effective.  When a houseful of plants is infested no time should be lost, and the evening is most suitable for dealing with the pests.  The plants ought to be quite dry and the house closely shut.  A dense cloud of smoke without flame is required.  Allow the smoke to do its deadly work during the night.  Early next morning syringe the plants freely, and in the course of an hour or so give air.  The other remedy is to use one of the many liquids which are inimical to the life of