32 THE MAGAZINE OF HORTICULTURE. 



Plants as Purifiers of the Air within Doors. — Some people are 

 not yet able to understand the different or even opposite effects of the leaves 

 and the flowers of plants upon the air we breathe. The flowers, like ani- 

 mals, absorb oxygen and give out carbonic acid gas : the leaves, on the con- 

 traiy, absorb carbonic acid gas, and give out oxygen. Hence, in this re- 

 spect, house plants, when not in flower, tend to purify the air of the room in 

 which they are kept, and might advantageously be cultivated to a certain 

 extent for this very purpose. But there is still another point to be consid- 

 ered in relation to this matter. The leaves of plants not only serve to re- 

 generate the atmosphere of a room by absorbing the noxious gases emitted 

 from the lungs of human beings, and giving out that vital quality which 

 supports our respiration, but they also evaporate into the air a great quan- 

 tity of moisture. It is customary with those who warm their rooms by 

 means of a close stove, to place a vessel of water upon it, in order to sup- 

 ply any deficiency of atmospheric moisture occasioned by the heated stove. 

 If we reflect a little upon the enormous quantity of moisture taken up from 

 the earth, and evaporated into the air by almost every growing plant, we 

 should be convinced that a few geraniums, rose bushes, or any othor decidu- 

 ous plants, would supply a room with a sufficient abundance of this health- 

 ful moisture. House plants, therefore, cannot be too highly recommended, 

 for their utility in promoting the wholesomeness of our indoor atmosphere, 

 as well as for purposes of ornament. The only precaution necessary to be 

 given, is, that whenever a plant is in flower, it should during that period be 

 removed from our sleeping rooms. 



A Curious Fact. — What is in common language termed a bulbous root 

 IS by Linnaeus termed the Hybernacle, or Winter Lodge of the young plant. 

 These bulbs in every respect resemble buds, except in being produced 

 under ground, and include the leaves and flower in miniature, which are to 

 be expanded in the ensuing spring. By cautiously cutting, in the early 

 spring, through the concentric coats of a tulip root, longitudinally from the 

 top to the base, and taking them off successively, the whole flower of the 

 next summer's tulip is beautifully seen by the naked eye, with its petals, pistil 

 and stamens : the flowers exist in other bulbs, in the same manner, but the 

 individual flowers of others being less, they are not so easily dissected, or 

 60 conspicuous to the naked eye. In the buds of the Daphne Mezereon, 

 and in those of the Hepatica, and at the base of the Osmunda lunaria, a 

 perfect plant of the future year may be found, complete in all its parts. 



Changes in Plants. — It may be observed that many flowers are fur- 

 nished with the remains of parts that once existed, and which have become 

 abortive. Thus the Verbena of England has four stamens, while that of 

 Sweden has only two. There is a similar circumstance belonging to the 

 class of insects which have two wings, the Diptera. Two little knobs are 

 found placed each on a stalk or peduncle, generally under a little arched 

 scale, which appear to be the rudiments of hinder wings ; and are called by 

 Linneeus, halteres, or poisers, a term of his own introduction. Other ani- 



