VI 



The present list comprises 1116 species and varieties of 

 ferns and 97 of fern allies ; this is exclusive of British 

 ferns, of which 536 varieties are in cultivation. 



The collection falls into three great groups : — (i.) 

 Tropical ; (ii.) Temperate ; and (iii.) Hardy Ferns. 



The Tropical Ferns are cultivated in No. II. House. 



The Temperate Ferns are cultivated in No. III. ; the 

 Filmy Ferns have a separate House (No. II. A), con- 

 structed for the special treatment which they require. 

 The fine collection of Temperate Tree Ferns is contained 

 in the Temperate House. 



The Hardy Ferns are arranged on and about a small 



7 

 rockery, ™ of the Key Plan, and forming the south 



boundary of Lawn L. 



The structural development of the buildings in which 

 the collection is housed has kept pace with its growth. 

 Their history may be given briefly. 



The Tropical Fern House (No. II.) is a span-roofed 

 house 129 feet long, 34 feet broad, and 15 feet high in the 

 centre. It has a wide transept on the south side, 40 feet 

 long. 33 feet wide, and 19 feet high. 



In 1841 the site of this house was occupied by two 

 lean-to houses used for miscellaneous collections of stove 

 plants. They are enumerated in Dr. Lindley's Report to 

 the Treasury (1838) as Nos. 2 and 3 ; the former stood to 

 the west, and was 50 feet long ; the length of the other 



