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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 modified 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. 10. 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, Poly podium, 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 



