122 
The other species, Shepherdia Canadensis Nutt, the Soapberry 
of the northern States and British America, bears yellowish-red, 
sweetish-acidulous and bitter berries; these, according to Prof. 
Penhallow, contain 0.74 per cent. of saponin to which they owe 
their persistent bitter taste and their well known property of foam- 
ing when triturated in a little water and beaten up; the thick 
cream-like, strawberry-colored foam thus produced is a favorite 
dish of the natives and, if sweetened, quite palatable. The ber- 
ries are also preserved, dried or made into jam. 
Another plant of this family, with edible fruit, is Alacagnus 
argentea Pursh, the Silverberry of our northern middle States, and 
an attractive garden plant on account of its silvery-white foliage 
and the delicious fragrance of its flowers. The globose berry is 
dry and mealy and not at all appetizing. 
The fruit or hip of several of our wild Roses, after being touched 
by frost, is sweet and palatable; as it persists through most of the 
winter, when hardly anything else is available, it sometimes be- 
comes useful food to the natives as well as to birds and mammals. 
Rosa Nutkana Presl., the Nutka Rose, ranging from the northern 
Pacific coast to the Rocky Mountains, is the most showy of west- 
ern Roses, having the largest flower and fruit; the latter is juicy 
and pleasantly acidulous and an excellent antiscorbutic for the 
Indians of Alaska. 
Passing over the many native plants yielding edible seeds, 
specially of the Gramineae, I shall close with the notice of a few 
of those whose stem and foliage afford food to the Indians. In 
this connection the genus Agave is first to be mentioned; it is 
essentially Mexican, only a few species extending into our southern 
territory, and has always been of the greatest economic importance. 
The sap of A. Americana, a species sparingly naturalized, but not 
indigenous, north of the Rio Grande, is converted into a weak alco- 
holic beverage called “pulque,” the national drink of Mexico. 
Other species, baked, supply the “ mezcal de comer,” an excellent 
article of food, and also, by fermentation and distillation, a strong 
drink called “aguardiente mezcal.” The edible part consists of 
the thick juicy base of the leaves, the fleshy axis and central bud, 
together forming the “cabeza” or head which is slowly baked in 
a pit or oven. In the raw state no sugar can be discovered in 
