country, " huariqui " (Ibervillea sonorae); during the rainy- 

 season green stems arise from these large woody plant-bodies, 

 which at other times remain in a resting condition. 



A group of the lily family will be found in the central 

 portion of this house. This comprises members of the genera 

 Aloe, Yucca and Dasylirion. A group of cacti will also be 

 found here, the most imposing figure of which is the giant 

 cereus, Cereus giganteus, known as " suwarro" by the Mexi- 

 cans and Indians of its native country, Arizona and Sonora. 

 The plants here shown were obtained by an expedition sent 

 to those regions by the Garden in 1902, and they represent 

 perhaps the largest specimens in cultivation in the east. 

 Several large specimens of the hedgehog cactus, secured at 

 the same time, form part of this group. The Indians in 

 the desert often secure a supply of drinking water from these 

 plants by cutting off the top and macerating the interior 

 substance. A number of other large and rare cacti secured 

 by a Garden expedition of 1906 have recently been added to 

 this collection. On the remaining corner benches will be 

 found the fig marigolds, from southern Africa, desert mem- 

 bers of the pineapple family, and representatives of the 

 spurge family. 



House No. «! Many families are shown here, the repre- 

 sentatives of which are tropical. The members of the mimosa 

 and senna families, largely represented in this house, are 

 curious in their sleep movements ; as daylight wanes the 

 leaves begin to droop and the leaflets to fold up. Belong- 

 ing to the senna family may be mentioned : the logwood tree 

 (Haematoxylon camjjechianum) , widely distributed through- 

 out tropical America; the copaiba tree (Copaiva officinalis), 

 one of the trees from which copaiba is obtained ; and the 

 tamarind tree (Tamarindus indica), valuable for its fruit. In 

 the mimosa family the humble or sensitive plant (Mimosa 

 ■pudica), whose leaves fold at the least touch, is of peculiar 

 interest. The mahogany tree (Swietenia Mahagoni), and the 

 cocaine plant (Erythroxylon Coca), from South America, are 

 important economic plants. In the custard-apple family are 



