MONTHLY CALENDAR. 725 



these, however, must be considered. Heat, probably the prime mover, must 

 be supplied within certain limits, and regulated by the natui-al habitat of the 

 plant ; tropical plants must have tropical heat, unless they are natives of the 

 temperate climates, or of high mountains and table-land. Nothing that I am 

 aware of will grow in a temperature under 32°, or over boiling-point. A happy 

 medium of from 40° to 80° is best for most plants. 



2270. Light is most essential to the well-doing of plants of any kind ; the 

 want of it is sure to be indicated by a weak, pale, and spindling growth, 

 the result of placing the plants in a room far away from the glass : the more 

 directly overhead they receive light the better ; but the ordinary variations of 

 light and darkness are of no less consequence, since it is said that plants 

 inhale under the influence of light, and respire in the dark. 



2271. Moisture, again, so necessary for the support of plants, must be sup- 

 plied in proper quantities. When shall I water my plants ? is a vexed ques- 

 tion, yet one that will admit of no definite answer, as some plants want more 

 than others ; some more or less at certain times, or under particular circum- 

 stances. Observation and tact must be exercised, — useful qualities under any 

 circumstances, and particularly necessary in the cultivation of plants. 



2272. Ferns are by many considered to be a remnant of the vegetation of 

 a past era in the history of the earth, and associated with that rank luxu- 

 riant growth, some remains of which are seen at the present day. The treat- 

 ment they require would seem to confirm this view ; most of them delight in 

 a loose soil, abundant moisture, and a warm humidity in the air. Many kinds 

 are hardy ; some are native of our own climate : yet it is observed by expe- 

 I'ienced cultivators that those species which are found in temperate climates 

 grow much finer in tropical ones ; that sorts that live in England in the open 

 air grow luxuriantly in a stove ; showing that, under a higher temperature, they 

 become much more largely developed. However, in the cultivation of them, 

 it is not necessary to go beyond what is ordinarily done. Hardy sorts may be 

 grown out of doors, and those that will stand a greenhouse temperature are 

 as well grown in a greenhouse as anywhere : they will be none the better for 

 increased size, but rather the contrary. The serrature of the fronds, the form 

 and position of the fructification, would be less interesting if the fronds them- 

 selves were enlarged. Some kinds, indeed, are naturally large, and the 

 larger the more valuable, — as the Dicksonias or tree-ferns ; but these require a 

 large house to grow them properly. Our object is less to speak of particular 

 genera than to give a few hints for the culture of them as a whole. 



2273. In planting the fern-case, it is best to choose sorts of very dwarf 

 compact habit. This will allow for a little drawing up of the fronds from 

 confinement. A mixture of loam, leaf-mould, and sand, will be best for them 

 to grow in ; but it should be liberally mixed up with broken pieces of sand- 

 stone, or broken flowerpots, and small pieces ot charcoal. These will hold a 

 supply of moisture without stagnating ; but water should remain unabsorbed, 

 so that the cases must be pro\'ided with suitable drainage ; and although the 

 confinement of the case will agree with many Ifems, yet some ventilation is 



