21 



Air will prevent the plants from being drawn up 

 weak, and causes them to have a fine green colour, 

 with thick, firm, robust leaves. {Mills on Pine 

 Apple i 31.) 



In the winter months, advantage ought to be taken 

 of ail bright days, even should the frost be intense in 

 the night, by opening the sashes or ventilators a 

 little ; one sash or ventilator in every three should 

 be tilted or let down, at top or back of the house or 

 pit ; and as the season advances, a proportionately 

 greater quantity of external air must be admitted. 

 In summer, when the minimum temperature of the 

 external atmosphere is never greater than 52 degs., 

 the sashes of the pits may be left a little raised in the 

 night. This will be found to strengthen the young 

 plants astonishingly ; and when the sun is bright, 

 every sash should be elevated six inches, front and 

 back alternately ; which will prevent the plants from 

 becoming long and narrow-leaved, and give them a 

 robust and stocky character. {Grlendinning on Fine 

 Apple ^ 45.) 



Mr. Mills' observations upon this point are excel- 

 lent, and his directions most practically correct, with 

 the exception of keeping his temperatures rather too 

 high. He says — 



There is no doubt but, like the cucumber, pine 

 plants do best wdien kept moist all night by steam or 

 otherwise, and also by being dried during the day ; 



