CXCl 



surface on which it rested. If the seed be cut, the worm will soon 

 cover up the hole with a transparent membrane of silk ; and if two of the 

 opposite angles be cut, the movements of the worm can then be seen, if the 

 seed be held against the light. It then becomes evident that the jerking 

 motion is conveyed by the worm holding fast to the silken lining by its 

 anal and four hind abdominal prolegs, which have very strong hooks, and 

 then drawing back the head and forebody and tapping the wall of its cell 

 with the head, sometimes thrown from side to side, but more often brought 

 directly down as in the motion of a wood-peckers head when tapping for 

 insects. In drawing back the forebody, the thoracic part swells, and the 

 horny thoracic legs are withdrawn, so as to assist the jaws in receiving 

 the shock of the tap, which is very vigorous and often given at the rate of 

 two a second and for twenty or more times without interruption. It is 

 remarkable that this, of all the numerous seed-inhabiting Lepidopterous 

 larvae, should possess so curious a habit. The seed will move for several 

 months, because, as with most Tortricidous larvje, this one remains a long 

 time in the larva stale after coming to its growth and before pupating. 

 Mr. Barnes gives the following account of the plant, received through 

 Capt. Polhamus, of Yuma, A. T. It seems to be called both Terba de 

 flecha and Colliguaja by the Mexicans : 



^^Arrozv-rveed (^Terba dejiechd). — This is the name the shrub bears that 

 produces the triangular seeds that during six or eight months have a con- 

 tinual jumping movement. The shrub is small, from four to six feet in 

 height, branchy, and in the months of June and July yields the seeds, a pod 

 containing from three to five seeds. These seeds have each a little worm 

 inside. The leaf of the plant is very similar to that of the 'Garambullo,' 

 the only difference 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 perfectly 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 counteracted by an antidote." 



Mr. Riley stated that the seed of Tamariscus was known to be moved 

 by a Coleopterous larva {Nanodes tamarisci) that fed within it; and he 

 concluded by describing and exhibiting a still more wonderful jumping 

 property in a seed-like body which may be observed in our own woods. 

 It is a little spherical seed-like gall produced in large numbers on the un- 

 derside of the Post and other oaks of the White Oak group. This gall drops 

 in large quantities to the ground and the insect within can make it bound 

 twenty times its own length, the ground under an infested tree being some- 

 times fairly alive with the mysterious moving bodies. The noise made 

 often resembles the pattering of rain. The motion is imparted \sy the 

 insect in the pupa and not in the larva state. He presented the follow- 

 ing description of the gall, which maj' be known by the name of ^uercus 

 saltaiorius, the black fly which issues from it having been described as 

 Cynips saltatorius by Mr. H. Edwards of San Francisco : 



Gall of Cynips saltatorius. — Formed in summer on the underside of 

 the leaves of ^uercus obtusiloba, ^. macrocarpa, and ^. alba, often to 



