1 8 TETTIGJD.E OF NORTH AMERICA 



gidca parvipcniiis, with a twelfth Leitz oil immersion objective, 

 the author observed a thin undulate protoplasmic keel, which 

 arises close to the head and extends nearly the whole length of 

 the body (Fig. 4A), but becoming attenuated and disappearing 

 near the extremity of the body. The body of the spermatozoa 

 is exceedingl)' long and hair-like, bending from side to side in 

 the medium in which it was examined. Motion is communi- 

 cated by the waving keel movements which pass along 

 throughout its length. This keel or carina acts as a long fin 

 which propels the body. It seemed on first viewing these 

 spermatozoa that a spiral motion in the axis of the body 

 was apparent, but on further examination and waiting for the 

 motions to become slow it was found that this was a deception 

 caused by looking on the dorsal aspect of the body, the 

 undulating motion giving a false impression of revolutions. 

 The spermatozoa of Tcttigidea has a very short compresso- 

 pointed head-piece and comparatively short tail-piece. 



In Paratcttix cucuUatns (Fig. 4B) the body of the spermato- 

 zoon is exceedingly drawn out into a hair-like form. The head 

 is short, thin, and acutely pointed; the middle-piece is formed 

 into a high, rather short, protoplasmic keel. Commencing at 

 the point of meeting with the head, the middle-piece is sud- 

 denly e.xpanded and nearly the same width for a short distance 

 backward, when it becomes rapidly attenuated and continues 

 as an unkeeled portion, finall}' joining the long hair-like tail. 

 Paratettix spermatozoa are keeled much wider than those of 

 Tettigidea, and in this genus the keel extends only a small 

 part of the whole length, the edge of the keel not being sin- 

 uate as in Tcttis-idca. 



HOW THE EGGS ARE LAID. 



Speaking generally, when the female desires to lay her 

 eggs, she selects a suitable spot on the earth, sometimes on the 

 muddy ground {Paratcttix), or on vegetable mold, or among 

 moss and lichens (Tcttix and Tcttigidea). Satisfied as to the 

 spot, she curves the abdomen under her; the blades of the 

 ovipositor, directed downward, are forced into the ground. 



