THE BULB BOOK 



available. Of course, the amount of moisture in the atmosphere will 

 be regulated largely according to the season, and the plants that are 

 grown. During the spring and summer months, for example, the 

 thermometer will often register over 90'' and 100^ F. in a stove 

 during the daytime, and the humidity of the atmosphere will be 

 palpable to anyone entering, especially when spectacles are worn, as 

 the vapour immediately condenses on the cooler glasses. 



Notwithstanding the heat and moisture, it is essential to have 

 such hothouses properly ventilated, otherwise the air would become 

 so foul and stagnant that neither plants nor gardeners would be able 

 to live in it. The modern horticultural builder, in conjunction with 

 the gardener, knows exactly how to arrange the boilers, pipes, and 

 ventilators, so that a maximum amount of heat may be secured at 

 the least cost. At the same time, by proper ventilation, the air will 

 be purified, and but little heat will be allowed to escape. 



The "greenhouse" is a glass-house also supplied with hot-water 

 pipes and boilers ; but as plants requiring less heat and moisture are 

 grown in it, there is no necessity to maintain such high temperatures. 

 During the summer months, say from April till October, no fire-heat 

 whatever need be used, as the glass will retain during the night-time 

 much of the heat acquired during the day. During the winter months, 

 from October till the end of March, a certain amount of artificial heat 

 must be infused so as to maintain a night temperature of 45'-55'^ F. 

 "When some plants that are on the border line between hardy and half- 

 hardy, or somewhat tender, are grown, very little artificial heat is 

 required during the winter season, just sufhcient to keep the frost out. 

 Plants of this character are often wintered in cold frames and given 

 plenty of air and light on all favourable occasions, the only protection 

 they require being a mat or two thrown over the glass at night when 

 the frost is likely to be severe. 



The following genera embrace bulbous, tuberous, or rhizumatoua 

 plants that are usually grown under glass either in a " stove " or 

 "greenhouse." The genera marked with an asterisk (*) are all 

 monocotyledons, and have true bulbs or corms. The cultural details 

 are given under each genus in the body of the work : — 



Achimcnes. Androcymbium. *Blaiidfordia. 



*Albuca. Anigozantlios. Boussingaultia. 



Alocasia. *Anoigantlius. *Bo\viea. 



Alpinia. Arisieiua. *Brunsvigia. 



*Arnmocliari.s. A.s])idistra. *Buphane. 



Ainouiuiii. Begonia. Burbidgea. 



Aniorphophallus. Beschorneria. Caladium. 



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