BOTANY: I N, ROSE 
73 
HOOC-CHsN - CO 
HOOCCH2N - CO 
CO 
CO 
NH-CiCHCfiHs 
(XVIII) 
NH - CHCIIoCeHs. 
(XV) 
Other methods for synthesizing hydantoin compounds of this type 
(and their sulphur analogues) are being developed. This work will 
include not only the study of hydantoin derivatives of dipeptides but 
also tripeptide combinations of analogous constitution, and also an 
investigation of their behavior towards liydrolytic agents and enzymes. 
1 Morner, Zs. physiol. Chem., 34, 207 (1901). 
2 Lippich, Ibid., 90, 441 (1914). 
» Wheeler and Hoffman, Amer. Chem. J., 45, 368 (1911). 
*Ruhemann and Cunnington, London, J. Chem. Soc, 75, 958 (1899); Ruhemann and 
Stapleton, Ibid., 77, 246 (1900); Wheeler and Hoffman, loc. cit. 
RECENT EXPLORATIONS IN THE CACTUS DESERTS OF 
SOUTH AMERICA 
By J. N. Rose 
DEPARTMENT OF BOTANICAL RESEARCH. CARNEGIE INSTITUTION OF WASHINGTON 
When the cactus investigation for the Carnegie Institution of Wash- 
ington was taken up a few years ago with Dr. N. L. Britton, a definite 
plan for field work in the deserts of North and South America was out- 
lined. And since the Cactus family is confined to America, this meant a 
survey of its entire distribution. 
The exploration of the deserts of South America was referred to me, 
and I have spent two seasons in exploring these regions ; the first on the 
west coast, in Peru, Bolivia, and Chile, and the second on the east 
coast, in Brazil and Argentina. The exploration was confined chiefly 
to the deserts, as the cacti as a class are desert loving plants. A cactus 
desert, however, does not necessarily mean a desert like the Sahara or 
the desert of Arizona. 
We found as a result of our investigation that South America contains 
six great cactus regions: (1) The desert of northern South America, 
including northern Venezuela and Colombia. This region we have not 
yet studied at first hand. (2) The great Peruvian and Chilean desert 
which extends from northern Peru to central Chile and from the Pacific 
Ocean to the top of the Andes, having a length of 2000 miles and a breadth 
of 50 to 300 miles. (3) The desert of Argentina, extending from the 
central part of Patagonia along the east side of the Andes well into Bolivia . 
Read before the Academy, November 16, 1915. Received January 6. 1916 
