142 Miscellaneous. 
leaves of a dark varnished green. ‘‘ It bears the seeds only once in 
two years. The tree is called Brincador (jumper), and the seeds 
are called Brincaderos. The seeds are more quiet in fair weather, 
and lively on the approach of a storm.” 
Prof. Westwood mentions the fact that the plant is known by 
the Mexicans as “ Oolliguaja ;” and Prof. E. P. Cox, formerly State 
Geologist of Indiana, now living on the Pacific coast, informs me 
that the shrub has a wood something like hazel or whahoo; that 
the leaf is like a broad and short willow leaf. He confirms the 
statement as to its poisonous character; that a stick of the shrub, 
when used by the natives to stir their ‘‘ penola” (ground corn-meal, 
parched), purges, and that the shrub is used to poison arrowheads. 
The plant is undoubtedly Kuphorbiaceous. 
The peculiarity about this insect is that it is the only one of its 
order, so far as we know, which possesses this habit; and it is not 
easy to conceive of what benefit this habit can be other than the 
possible protection afforded by working the seed, after it falls to the 
ground, into sheltered situations. 
The true explanation of the movements of the larva by which the 
seed is made to jump was first given by me in the ‘ Transactions of 
the Saint Louis Academy of Science’ for December 6, 1875 (vol. ii. 
p. exci). 
The jumping-power exhibited in this “seed,” however, is trifling 
compared with that possessed by a little gall which I also exhibit. 
This gall, about the size of a mustard-seed, and looking very much 
like a miniature acorn, is found in large numbers on the underside 
of the leaves of various oaks of the white-oak group, and has been 
reported from Ohio, Indiana, Missouri, and California. It falls 
from a cavity on the under side of the leaves, very much as an 
acorn falls from its cup, and is sometimes so abundant that the 
ground beneath an infested tree is literally covered. It is produced 
by a little black Cynips, which was described as Cynips saltatorius 
by Mr. Henry Edwards. The bounding motion is doubtless caused 
by the larva which lies curved within the gall, and very much on 
the same principle that the common cheese-skipper (Piophila caser) 
is known to spring or skip. Dr. W. H. Mussey, of Cincinnati, in a 
communication to the Natural History Society of that city, Decem- 
ber 1875, states, in fact, that such is the case, though members of 
the California Academy who have written on the subject assert 
that the motion is made by the pupa, which I think very impro- 
bable. At all events the bounding motion is great, as the little 
gall may be thrown 2 or 3 inches from the earth; and there are 
few things more curious than to witness, as I have done, a large 
number of these tiny galls in constant motion under atree. They 
cause a noise upon the fallen leaves that may be likened to the 
pattering of rain.—Proc. United States Nat. Mus. p. 6382, 
