47° BOTANICAL GAZETTE [JUNE 
of collectors and cactus growers, the importance of whose cooperation in this 
knotty group can not be overestimated. The work will appear in ten fascicles 
at intervals of two months, constituting when complete a handsome royal 
octavo volume of 600 pages or more. 
With the exception of a rather comprehensive introduction devoted to 
general morphology and geographic distribution, the work is purely syste- 
matic, with short, excellent, clear cut descriptions. In his chapter on distri- 
bution the author brings up the old but interesting question of the origin of 
old world forms. The original home of Opuntia vulgaris remains unsettled. 
The widespread occurrence of Rhipsalis in tropical Africa is logically 
accounted for through the instrumentality of bird migration, the mucilaginous 
juice of the berry suggesting the possibility of an occasional seed clinging 
to feathers for a considerable period. The “author’s index"’ presents a 
novel feature in the form of personal or biographical comment, furnishing to 
cactus lovers an interesting and useful compendium of information. 
The family is subdivided as follows: 
I. Subfamily CEREOIDE#. 
Tribe 1. Echinocactee.—Cereus, Piloceréus, Cephalocereus, Phyllocactus, Epiphyl- 
lum, Sie aN Echinocereus, Echinocactus, Melocactus, Leuchtenbergia. 
ribe 2. Mamillarig.— Mamillaria, Pelecyphora, Aniocarpus. 
c. 3. Piticlden Pfeiffera, Hariota, Rhips 
Il. Subfamily OPUNTIOIDE. 
Tribe 4. Opuntig.— Opuntia, Nopalea, Pterocactus. 
IIL. Subfamily PErRESKIOIDE#. 
Tribe 5. Peireskiee—- Peireskia. 
It will be noticed from the above that twenty genera are recognized, of 
which one is new. Cephalocereus (Pfeiff.) em. K. Sch. has for its typical 
representative our Mexican “ old man cactus,” Cephalocereus senilis. Ptero- 
cactus K. Sch., from Argentina, is a most remarkable representative of the 
i Opuntioidex, being Gistmg wished not only nee ae other genes of its — 
bohestiiiaing all other Cactacee, by its d bro 
i 
. e: urther particulars a far as sndap are of i eas sds interest, will 
_ be mentioned from e parts appear 
—E. B. Unine. 
” heated wadding: 
apie first described in — by Brongniart, 
sh ‘numerous studies have been made of the nectar glands of the 
of 
xamination as ee 
Sine ect ae Nee ea 
Bey es SS SO Dee se ee 
