442 



DOMESTIC NOTICES. 



treatment as was conferred on other tropical 

 plants, once having ascertained they came from a 

 tropical country, without making any inquiry as 

 to their habitats, or the nature of the atmosphere 

 in which they luxuriated. The changes of tem- 

 perature and season they experienced never oc- 

 curred to the grower as a matter worthy of in- 

 quiry; consequently, plants whose natural habi- 

 tats, or places of growth, were branches of trees, 

 when submitted to such unnatural treatment, soon 

 ceased to exist. 



Mr. Cattlf.y having succeeded, to some ex- 

 tent, others viewed his collection with an admiring 

 eye, and also embarked in the same culture, still 

 improving on the method adopted by the tirst cul- 

 tivators; so that, after a short period, a few of 

 them were to be found in every good plant collec- 

 tion, till they at length became what Mr. Dow- 

 ning, in his note to our former letter, calls the 

 ultimatum of British culture. Many difficulties 

 have been thus removed ; and it is now ascertained, 

 from experience, that they will not thrive without 

 a soil, drained so as to prevent any stagnant 

 moisture remaining about their roots, and in some 

 cases a high temperature, and an atmosphere 

 nearly approaching the point of saturation. 



Having given some account of the difficulties 

 early cultivators had to encounter, we wish now 

 to caution those of your readers, that may possess 

 some of them, against high night temperature; as 

 it is the greatest evil attending their cultivation. 



That all plants require a season of rest, is a 

 subject that no judicious plantsman will question. 

 We are informed, that in the mountainous islands 

 of the Indies, the air upon the mountains becomes, 

 soon after sunset, chilled, and condensed; and 

 owing to its superior gravity, it descends and dis- 

 places the warm air of the valleys. Therefore, 

 nature and reason point out to us the propriety 

 of a lower temperature for all plants at night tlian 

 in the day time. The best time for this resting 

 season is from the beginning of November to the 

 end of February. All the Brazilian orchids seem 

 to be an exception to this rule ; as they are found 

 most active in their growth from the month of 

 November to April, and must then have their 

 season of rest. 



The temperature of the orchidaceous-house, 

 during this time, should be kept from 60 to 65 

 degrees, during the day, and from 50 to 55 de- 

 grees at night. It is necessary that the tempera- 

 ture of all plant houses be kept much lower during 

 the night than in day time. The reason is evi- 

 dent. If heat and moisture be applied to a plant 

 in a growing state, it must of neeessit)' grow in 

 proportion to the amount of those agents ; as it is 

 in day light only that plants can digest their food, 

 and harden their texture, the amount of digestion 

 and hardening will be in proportion to the inten- 

 sity of the light they receive. If they are com- 

 pelled to grow in the dark, they are filled with 

 undigested sap, and their wood becomes watery 

 and soft. 



The following extract, from the Theory of Hor- 



ticulture, fully coincides with these remarks: " The 

 eti'ect of cold is, to diminish excitability of heat to 

 stimulate it ; but if the latter stimulus be con- 

 stantly equal, it may be conceived, that the ex- 

 citability would soon become impaired or expended. 

 Nature has, however, provided against this result ; 

 not only by the fluctuations of temperature, that 

 occur at difl'erent periods of the day, but more 

 particularly by the periodical fall of temperature 

 at night, and its rise during the day. An ar- 

 rangement intimately connected with all the vital 

 actions of vegetation. 



In the day, when light is strongest, and its eva- 

 porating and decomposing powers are most ener- 

 getic, temperature rises and stimulates the vitality 

 of plants, so as to meet the demand thus made 

 upon them. As light diminishes, and with it, the 

 necessity for excessive stimulus, temperature falls, 

 and reaches its minimum at night, — the time when 

 there is the least demand upon the vital forces of 

 vegetation. So that plants, like animals, have 

 their diurnal seasons of action and repose. During 

 the day, the system of a plant is exhausted of 

 fluid, by the aqueous exhalations that take place 

 under the influence of sunlight. At night, when 

 little or no perspiration occurs, the waste of the 

 day is made good by the attraction of the roots; 

 and by morning, the sj'stem is again fllled with 

 liquid matter, ready to meet the demand to be 

 made upon it on the ensuing day. No plants will 

 remain in a healthy state unless these conditions 

 be observed." 



Orchidaceous plants, while dormant, require no 

 more water than what will keep their pseudo 

 bulbs and foliage from shriveling; particularly 

 those in pots, as the preservation of their roots 

 in winter is of the greatest importance. And 

 those in pots are found more difficult to keep than 

 when other modes of cultivation are adopted ; 

 owing, no doubt, to their being in immediate con- 

 tact with moisture. As the size of a plant is in 

 some measure proportional to the surface of the 

 organs that are destined to convey food to it, and 

 as a plant gains an additional mouth with every 

 libre of root; and though those mouths, or spon- 

 gioles, become dormant or drop off in winter, the 

 preservation of the roots is of the utmost impor- 

 tance. For when they are left to perish, the 

 plant becomes sickly ; the amateur is disappointed ; 

 he watches in vain to see them expand their 

 bloom, — the only return for his outlay. 



Wood-lice are also very injurious to Epiphytal 

 orchidacea, as they eat the spongelets, or young 

 extremeties of the roots, by which absorption takes 

 place; consequently, the plants often receive a 

 check by the destruction of those organs when 

 they are in a growing state. Every means should 

 be resorted to in order to destroy them. The best 

 way we know of, is to look over the plants at 

 night with lamplight, and kill as many of them as 

 can be found. A small spring tweezers is very 

 useful for the purpose. After dark, they come 



