674 The American Naturalist. [July, 
letter to Prof. Riley from M. Chretien, of the French Entomological 
Society, the plant was referred to as a Mexican euphorbiaceous plant 
called Colliguaja odorifera Moline. About this time Mr. J. M. Rose, 
of the botanical division, brought to Prof. Riley specimens of plants 
recently collected by Dr. Edward Palmer, who sent with the plants 
specimens of the capsules, thus rendering it certain that the jumping 
bean occurs on this particular plant. It turns out to be undescribed, © 
has been referred to the genus Sabastiania, and will be described by 
Mr. Rose as S. palmeri. Prof. Riley decides that the reference given 
by M. Chretien is erroneous, as Bentham and Hooker give Colliguaja 
odorifera as from South America, and there is no record of it from 
Mexico. Comparison of the specimens in the department herbarium 
showed that while evidently closely allied, Colliguaja is quite distinct 
from Sebastiania, which renders it rather remarkable that the name 
given by the Mexicans to the plant should be identical with that 
adopted for the South American genus. The name seems to be of 
Chilian origin, and was doubtless introduced into Mexico by the 
Spaniards. It is probably applied to various euphorbiaceous species 
having the same poisonous attribute, whether occurring in Mexico or 
south of the equator. 
A closely allied species of Sebastiania from the same localities (as 
yet undescribed, but which Prof. Watson will describe as S. pringlet) 
also shows evidence of being infested with Carfocapsa saltitans, and a 
third species (S. 4i/ocularis) is infested by an allied larva of a moth 
which Prof. Riley describes by the name of Grapholitha sebastiania. 
There is therefore good evidence that the insect causing the saltations 
of the ‘‘ beans’’ develops in the capsules of at least two different 
species of the genus Sebastiania. The young larva doubtless hatches 
from an egg laid externally on the capsule, and penetrates the same 
while quite young, very muchas in the case of the common pea weevil. 
Dr. Palmer found S. palmeri only in certain cafions near Alamos, 
where it is popularly known as palo de la flecha cuero de las simellas 
brincaderos (arrow tree which produces the jumping beans). The 
plant exudes a good deal of milky juice, which is what the Indians 
use on their arrow-heads. It is a loose-growing shrub, from five to 
eight feet high, the wood very hard, and the milky juice readily crys- 
tallizing into a clear, white, brittle substance. In the appearance of 
the wood it reminds one somewhat of our witch-hazel, and in the leaf 
of a broad-leaved willow. As in the case of other Euphorbiacez, the. 
carpels, or each of the three parts of the capsule, dehisce, or suddenly 
split when ripe ; but when the larva inhabits the same the parts fail to 

