ORCHID-HOUSE. 



695 



in this simple way rears abundance of plants. 

 Water, when applied to keep the soil in a proper 

 degree of moisture, must be applied with the 

 greatest care, and administered with the finest 

 perforated cap on the syringe or watering-pot 

 possible, else the seeds will run a great risk of 

 being washed off. It is well in all cases to 

 cover the surface on which the sporules are 

 sown with hand or bell glasses, and to allow 

 them to remain until the plants have attained 

 a size nearly fit for potting off. After they are 

 transferred to the pots, even these should be 

 again covered for some time, as the young plants 

 are extremely delicate, and require to be grown 

 for a time in a still humid atmosphere. 



The vapour arising from carbonate of ammonia 

 has been applied to orchids with marked advan- 

 tage, causing them to assume a much more 

 healthy and vigorous appearance. It may be 

 applied by dissolving about two ounces of car- 

 bonate for a large house, and sprinkling the 

 hot-water pipes or flues about twice a-week. A 

 strong ammoniacal smell will be immediately 

 perceptible, similar to that of stable manure in 

 a high state of fermentation. 



Insects and diseases. — The most destijuctive of 

 the former are the cockroach, fig. 265, and the 

 woodlouse, fig. 266 ; the latter is the most to be 

 dreaded on account of its powers of multiplying 

 and the dificulty of combating it. They are sel- 

 dom seen during 



26S. / *^^ ^y' "■"^ °°'y 



feed during the 

 night, or in the 

 dark, and secrete 

 themselves in the 

 warmer parts of 

 the house, gene- 

 rally in the vici- 

 nity of the boiler 

 or under the 

 hot-water pipes. 

 They also find 

 their way within 

 the pots, locat- 

 ing themselves 

 amongst the 

 crocks, and feed- 

 ing upon the 

 roots unseen. 

 They dislike wa- 

 ter, and may be 

 dislodged if the 

 plant is plunged 

 in that element. 

 We find keeping 

 the places near 

 the boiler and 

 imder the pipes 

 saturated with 

 water prevents 

 them taking up 

 theirabode there, 

 while it also se- 

 cures the amount 

 of humidity necessary in the atmosphere of the 

 house. The slug, snail, white scale, brown 

 scale, mealy bug, black and green aphides, thrips 

 and red-spider, all attack them, but none are so 



much to be dreaded as the two first. Indeed, 

 the aphides, thrip, and red-spider only appear 

 upon them when something is wrong in the art 

 of culture. Excessive heats, droughts, &c., are 

 the cause, the appearance of the insects the 

 effect. Not so with the two former, and espe- 

 cially as regards the cockroach, for every addi- 

 tional plant added to the collection may carry 

 with it, if not the perfect insect, its eggs ; and 

 this is very much the case when orchids are 

 imported, it not unfrequently happening that 

 whole cases of these plants are entirely devour- 

 ed by these insects during their passage home. 

 On the arrival of plants from abroad, the utmost 

 vigUance should be exercised in searching for 

 such dangerous enemies. We, in general, after 

 examining the plants of orchids carefully, and 

 after removing all dead or decaying matter 

 attached to them, plunge them two or three 

 times in water heated to 100°, and afterwards 

 wash them thoroughly in tepid water, using a 

 brush for the removal of their eggs, which 

 water at any temperature less than would 

 destroy the plant would not effect. Cases of 

 imported plants should never be unpacked in 

 or near any of the hothouses, but in some place 

 distant from them in winter, and in summer 

 the operation may be carried on even at a dis- 

 tance from the garden. Amongst traps, we have 

 used common hyacinth glasses, half-filled with 

 sugar and water, or any sweet mucilage, a 

 little of it being smeared round the mouth of 

 the glass, set amongst the plants, but placing a 

 narrow slip of wood as a bridge between the 

 plants and the bottle. The cockroaches or 

 beetles, attracted by the sweetness, fall into the 

 water. Poison is also resorted to, and a mixture 

 of lard, honey, and arsenic is formed into paste, 

 and small pieces of it laid about on the shelving 



Fig. 266. 



Thb Cockrcvch. 

 Male and Female. 



or other parts of the house. Bell-glasses in- 

 verted, plunged in sand to the rim, and half 



