﻿FIELD AND FOREST. 57 



irregularly sub-conical, with the top flattened or concave, and with a 

 minute central nipple, sometimes obsolete ; the galls becoming de- 

 tached and falling to the ground in autumn, leaving a pale fulvous disc 

 at the bottom of the cavity. The gall has an average diameter of one 

 millemetre, and the color and general appearance of a minute acorn, 

 the base being paler than the sides, and conically produced to the cen- 

 tral point of attachment. The apical portion is slightly constricted 

 into a deep purple brown rim, and the top within the rim is flat with 

 a small central nipple." 



And now the question arises, how is such a tiny insect as the one 

 we have just been considering, enabled while confined within its en- 

 velope, to throw itself, case and all, with such force at so great a height 

 in comparison to its size ? That the walls of the gall are very thin and 

 elastic is readily seen, but even then, that the little soft fleshy atom 

 within should exert a sufficient muscular force to act upon the walls 

 of the case and throw it half an inch upward from its resting place, or 

 to a distance equal to twenty times its own diameter, seems perfectly 

 marvelous. A rolling motion is readily explained, as the mere chang- 

 ing of the centre of gravity in a round body like this, would naturally 

 cause a change in its position. We cannot say how the movement is 

 accomplished, but the specimen figured, while under the microscope, 

 was observed to jerk the flattened portion of the body, shown beneath 

 in the figure, in a violent manner, and it is supposed that it is by sim- 

 ilar movements, when tightly enveloped in its light, elastic case, that 

 the jumping is accomplished. 



Chas. R. Dodge. 



The Drumming of the Ruffed Grouse. 



(Bonasa tunbellus.) 



How does the Pheasant drum ? Singularly numerous have been the 

 answers to this question, yet, after a study of what has been written 

 in explanation of the manner in which the peculiar sound is produced, 

 we do not feel that a satisfactory solution has been reached ; but, on 

 the contrary, the conviction is forced upon us that these answers are 

 almost wholly chimerical. We cannot but think that the subject is a 

 more involved one than authors have supposed. However this may be, 



