ii8 The Method of Ovipositing. 



driven the ovipositor into the centre of the bud, there 

 comes a moment of complete rest, and the fly sits 

 motionless upon the bud. If it is fixed in this position 

 by dipping it into chloroform, nothing is seen of the ^^'g, 

 it still remains in the vagina. Then follows the second 

 part of the work, the pushing of the egg into the bud. 



The ^gg slips, with its enclosed egg-body, to the base 

 of the ovipositor between the origin of the two spiculae. 

 The egg-body glides over the point where the two 

 spiculae embrace the tenon of the seta, since the space 

 remaining open between the two spiculae is too small 

 to admit it. But the egg-stalk, which follows, slips 

 between the two spiculae, is seized by them, and 

 driven forward ; in this way the ^^^ is pushed 

 downwards into the ovipositor, with the egg-body 

 hanging out. 



When at last the ^%% is about to enter the canal 

 which has been bored into the centre of the bud, it 

 becomes evident that it is impossible for the canal to 

 admit the ovipositor and the egg-body to pass in at the 

 same time. The egg-body is always of much greater 

 diameter than the ovipositor ; on this account the ovi- 

 positor is next partially withdrawn by the fly, until the 

 pierced canal becomes empty ; the egg-body then enters 

 the pierced canal, and the ovipositor follows, pushing it 

 before it. In short, the whole forward motion is 

 dependent on the egg-stalk being propelled by the to 

 and fro movements of the two spiculae, and the ^g'g 

 reaches the end of the bored canal, while the egg-stalk 

 remains lying within it. 



The process of egg-laying, though it seems rather com* 



