COOK AND cook: THE MAHO OR MAHAGUA 153 



SUMMARY 



An apparatus to give a continuous record of sea-water salinity 

 by the measurement of its electrical conductivity is described. 

 A pair of electrolytic cells has been designed which when used 

 with a suitable alternating-current galvanometer will give 

 satisfactory operation in connection with a recorder. The tem- 

 perature compensation is obtained by placing both cells, which 

 are in the two arms of a Wheatstone bridge, in a uniform !em- 

 perature bath. 



ETHNOBOTANY. — The maho, or mahagua, as a trans-Pacific 

 plant. O. F. Cook, Bureau of Plant Industry, and Robert 

 Carter Cook. 



As noted previously in this Journal^ the word cumara or 

 kumara, a name for sweet potatoes, is found in the Pacific islands 

 and among tjie Quichua Indians of the interior valleys of southern 

 Peru, on the eastern slopes of the Andes. Considering the plant 

 as a native of America, the preservation of an American name 

 among the Polynesians appears significant. If the sweet potato 

 and its name were carried into the Pacific in prehistoric times, 

 other evidences of communication may be discovered. 



The underlying question is whether agriculture and civiliza- 

 tion arose independently in the two hemispheres, or had their 

 early development in America and reached Asia by way of the 

 Pacific islands. Did civilization grow from a single primary 

 root, or were there parallel developments among widely separated 

 peoples? The agriculture of ancient America undoubtedly was 

 indigenous, since it was based on native plants. Nevertheless, 

 several of the American plants, as the coconut palm, the sweet 

 potato, the bottle-gourd, the yam-bean, and the upland species 

 of cotton, appear to have been cultivated in the Pacific islands 

 and the Malay region long before the period of discovery by 

 Europeans. Civilization being an outgrowth of algriculture, 

 evidence from the cultivated plants seems pertinent. 



The maho, or mahoe, to use the Jamaican or West Indian name 



16:339. 1916. 



