634 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



rambullo, the ouly difierence being in the size, this being a little larger. 

 It is half an inch in length and a quarter of an inch in width, a little 

 more or less. The bark of the shrub is ash-colored, and the leaf is per- 

 fectly green during all the seasons. By merely stirring coffee, or any 

 drink, with a small branch of it, it acts as an active cathartic. Taken 

 in large doses it is an active poison, speedily causing death unless coun- 

 teracted by an antidote." 



lu a recent letter he states that he is informed that the region of 

 Mamos, in Sonora, is the only place where the plant grows ; that the 

 tree is about four feet high and is a species of laurel, with the 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 Brinca- 

 deros. The seeds are more quiet in fair weather, and lively on the ap- 

 proach of a storm." 



Professor Westwood mentions the fact that the jjlant is known by 

 the Mexicans as ^^ Colliguaja ;" 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 

 Euphorbiaceous. * 



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 con- 

 ceive of what benefit this habit can be other than the possible pro- 

 tection aftbrded 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. Ill, p. 

 cxci). 



The jumping power exhibited in this " seed" is, however, trifling com, 

 pared with that possessed in 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 under side 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-skii)per {FiopMla casei) is known to spring or skip. Dr. W. 

 H. Mussey, of Cincinnati, in a communication to the Natural History 

 Society of that city, December, 1875, states, in fact, that such is the 



