We believe cool houses - houses in which plants are merely to rest during the winter for summer use - will come into great favor. In a recent visit to Tower Grove Park, St. Louis, we were pleased to find the cool house, erected a few years ago, a great success. The house is a parallelogram, built of brick, the walls hollow, with a few narrow windows along the walls. The roof is partially opaque. The aim is to keep the temperature about 45°, so that they shall rest and not grow; although in this restricted light, some autumn blooming plants, were charmingly in flower. A large specimen of Malvaviscus mollis was especially gorgeous. Mr. Shaw, the controller of the Park, feels proud, as he has good reason to be, of the great success of the house. The cost of fuel for such structures, as well as the care required is very little indeed.