186 
successfully maintained, flowering every year in late spring and 
early summer (Journ. N. Y. Bot. Gard. 3: 96-98). During our 
study of the North American Cactaceae, which has now extended 
over several years, the species included by previous students in 
the genus Cereus have been critically examined; most of them 
have been seen in the living state, and living specimens are now 
in the conservatories of the New York Botanical Garden, and in 
those of the United States Department of Agriculture at Wash- 
ington. As these specimens have come into flower from time to 
time it has become increasingly evident that the conception of 
the genus Cereus by previous authors has been altogether too 
broad. This was inferred at the outset of the investigation from 
a study of the published descriptions and illustrations, and from 
the fact that the plant-body of species of Cereus ranges all the 
other gigantic species which inhabit southern Mexico. The type 
species of Cereus is Cereus peruvianus Miller, a night-blooming 
species native of South America, fine large specimens of which 
may also be seen in the conservatories of the Garden. Some 
genera have already been suggested as distinct from Cereus by 
one author or another. 
The most noteworthy recent study of these plants has been by 
Mr. Alwin Berger, gardener at the late Sir Thomas Hanbury’s 
amous home at La Mortola, Italy, entitled “A Systematic Re- 
vision of the Genus Cereus Miller” (Report Mo. Bot. Gard. 16: 
57-86. 1905), which isa great improvement over the preceding 
discussion of these plants by the late Professor Karl Schumann 
(Gesamtbeschreibung der Kakteen, ed. 2, 1903), inasmuch as 
Mr. Berger first definitely groups most of the species into sub- 
genera, more or less well-defined by floral and fruit characters ; 
whereas Professor Schumann was obliged to group them only in 
series, many of these being very unnatural, and based almost 
wholly on the plant-body instead of on the inflorescence. Mr. 
Berger’s contribution is a noteworthy advance, and we find our- 
selves largely in accord with his groupings of the plants, although 
there are some results in which we are obliged to differ with him, 
