400 SUGGESTIONS OX PLANT HOUSES. 



Cinerarias : — from Mr. W. Lee, Albion Road, Hammersmith : 

 Albion, a variety heavily tipped with deep rosy-purple ; and from 

 Mr. LiDGARD, Hammersmith : Morning Star, slightly tipped 

 with rosy-purple. They were both inferior sorts. 



Cyanotis vittata argentea : — from the Society's Garden. 

 This is a pretty little trailing plant, presented to the Society by 

 W. W. Saunders, Esq., Treas. RH.S. It quite resembles in 

 habit the older form of the species which is familiar in gardens 

 under the name of Tradeseantia zehrina, and has the leaves' of 

 similar colours, but the grey marking of the upper surface is 

 much more distinct and decided ; and it was hence considered a 

 desirable substitute for the older kind. 



Primulas :— from the Society's Garden : a collection of well- 

 flowered plants of different varieties of these very ornamental 

 spring flowers, among which the new salmon-red variety, called 

 very attractive. 



LV.— SUGGESTIONS ON THE CONSTEUCTION 

 OF PLANT HOUSES WITH A VIEW TO THE 

 ECONOMISATION OF SOLAE HEAT. 



By Thomas Morris, M-I.B.A-, 12, Megent Street. 



{Read before the Floral Committee, February Uth, 1861.) 



Heat being a natural principle or influence of the highest 



importance in horticultural pursuits, its consideration becomes au 



derived from the great source of natural heat that it is here 

 proposed to treat. The laws of optics, by which light is 

 governed, are applicable in many points; and, especially with 

 respect to reflection, they apply to heat also. The great defect 

 in the construction of many buildings for horticultural purposes 

 appears to me to have arisen from the neglect of such governing 

 natural laws. 



It is not my intention to dispute the vast, it may be, primary, 

 importance of light in buildings of this nature, but to show that 

 there is a practicable medium by which the greatest benefits of heat 

 and light may be associated. Light, however, has been so largely 

 insisted on by horticultural writers, that the employment of glass 

 has been carried to the utmost possible limit, plant houses having 



