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graecum, of tropical Africa and the Mascarene Islands; 
and Phalaenopsis, native in the East Indies and the Malay 
Archipelago. Other plants requiring the conditions here 
are the tropical or East Indian pitcher-plants, Nepen- 
thes, a collection of which will be found here. They 
are mostly vines, growing naturally on trees, their leaves 
curiously ie at the ends into hollow structures, 
provided with lids, and technically known as pitchers: 
which are often wrongly regarded as the flowers; these 
pitchers contain water and secrete from their sides a liquid 
which digests insects that fall or crawl into the pitchers; 
this form of nutriment is apparently not necessary at all, 
however, to the growth of the plants; the flowers are small 
but borne in large clusters arising from the stems and may 
often be seen in this collection. 
House No. ro. In this house is a large part of the 
collection of tropical ferns and their allies, and a part of 
the collection of cycads. The larger specimens of ferns 
and the tree-ferns will be found in houses 18 and 20, and 
the larger cycad plants in house 16. This house is the 
same size as No. 6. 
In so far as cultural conditions will permit, the ferns 
and their allies are arranged in families and genera, thus 
expressing relationships. The arrangement begins on 
the east side, as one enters from the central display house, 
and continues on and around the house, terminating on 
the west side opposite the point of starting. Among 
the larger fern genera here represented are: the maiden- 
hair ferns, Adiantum; the polypodies, Polypodium, and a 
few related genera; the brakes, Pteris; the shield-ferns, 
Polystichum and Dryopteris; the spleenworts, Asplenium; 
and the Boston fern and its relatives, derived from Nephro- 
lepis exaltata, a tropical species—an interesting group, 
showing the great diversity in forms which may result from 
a single species by selection and propagation. A large 
group, related to the ferns, is the selaginella family, repre- 
sented by many species; this family is largely tropical, a 
