assembled to facilitate the production of a monograph on 

 this family now in course of preparation by the Garden in 

 cooperation with the Carnegie Institution. In addition to 

 the plants in these houses, many hundreds of others are 

 located at the propagating houses. Nearly all these 

 plants are devoid of leaves, these organs, when present, 

 being mostly small and inconspicuous; in the genus Opuntia 

 they are usually present on the young growths as awl- 

 shaped bodies, while in some few species they are much 

 larger and remain for some time; in the genus Pereskia, 

 specimens of which will be found in house No. 8, the leaves 

 are large and well developed. The stems of the cacti are 

 fleshy and assume a great number of forms; in Opuntia 

 the stem is composed of joints, either cylindric or broad and 

 flattened. In Cereus and related genera the stems are 

 angled; in Carnegiea they are thick massive columns with 

 many longitudinal ribs; in Echinocactus the plant-bodies 

 are but little elongated, or almost globular, while in other 

 genera the plant-body is covered with rows of spirally ar- 

 ranged projections. The flowers of many cacti are ex- 

 quisite in form and color; they are borne on various parts 

 of the plant-body, in the turk's-head cactus on a curiously 

 modified portion of the top. 



In house 7 on the north bench and the north part of the 

 center bench is the genus Cereus and its many related 

 genera, Pachycereus, Cephalocereus, Leptocereus, Acan- 

 thocereus, Nyctocereus, Hylocereus, Selenicereus, Harrisia, 

 and others. Among these is the old-man cactus, Ce- 

 phalocereus senilis. On the west end of the center bench 

 and on the side bench opposite is a collection of the genus 

 Epiphyllum, often known as Phyllocactus. The broad 

 flattened parts of these plants are stems and not leaves, 

 the flowers being borne in the notches along their edges. 

 The flowers are very showy; many of them beautiful in 

 the extreme. On the south side of the center bench are 

 plants of the hedgehog cactus, Echinocactus, and also of 

 Echinocereus and Echinopsis. On the south bench is a 



