(147) 



placed here, in order to show the relationship of the orchid 

 family to the other endogenous ones. Curious among 

 the exogenous plants is the horsetail knotweed {Polygonum 

 equisetiforme), of southern Europe. Others of curious 

 interest are the pitcher-plants (Sarracenia), of the south- 

 eastern United States. The pitchers contain a liquid in 

 which the insects are drowned, the fluid resulting through 

 their decay being absorbed by the pitchers; these struc- 

 tures form a part of the leaves and are a modification of 

 the petiole. The sundews (Drosera) are also insectivorous 

 plants; they secrete a sticky substance from the glandular 

 hairs on their leaves, which can digest insects and other 

 animal matter. A plant useful as a ground cover in a 

 temperate house is Helxine Soleirolii, a member of the 

 nettle family. It grows rapidly and soon forms a beautiful 

 carpet of green. 



House No. 16. This house is about 28 feet wide and 43 

 feet long. Here is a collection of sago palms or cycads; 

 others will be found on the south end of the center bench in 

 house 10. This family of plants is represented by large 

 specimens of Cycas revoluta, from Japan; Cycas circinalis, 

 from the Molucca Islands; a single plant of the rare 

 Stangeria eriopus, from southern Africa, where it is known 

 as the kaffir's-head; the American genus, Ceratozamia, 

 named on account of the horns on the scales of the cone — ■ 

 Ceratozamia mexicana and Ceratozamia Miqueliana, both 

 from Mexico, are in the collection; a number of specimens of 

 the genus Zamia, including the small Florida coonties; 

 the kaffir-bread (Encephalartos) , from Africa; Macrozamia 

 Moorei, from Australia; and the Mexican genus Dioon. 

 The stems and trunks of plants of this family contain much 

 starch, which is extracted, in the countries in which they 

 grow, by crushing and washing, and passes into commerce 

 under the name of sago starch. On the walls are specimens 

 of aroid vines. 



House No. 18. This house is about 68 feet long; it 

 contains a part of the collection of tree-ferns, specimens of 



