the Biology of Sphodromantis guttata. 



97 



and by stretching the outer surface with the tips of the gono- 

 pophyses the vertical ridge, or swelling, is formed, which is 

 seen on the exterior alternating between the lines of the 

 vertical divisions. During the downward movement a 

 fresh supplv of secretion is left behind on the right half 

 of the face of the ootheca. The movement continues to 

 the base, where an addition is made to the length attached 

 to the support. Then the abdomen is inserted more 

 deeply, up to the base of the cerci, into the centre of the 

 righl side of bhe ootheca at B, and remains comparatively 

 quiet lor about two minutes. During this time the group 



Fig. 3.- — Diagram of movements of abdomen of female. 

 For explanation see text. 



of eggs on this position is laid, and the walls of the com- 

 partment are formed by compressing the only partially 

 vacuolated material displaced by the eggs. The abdomen 

 then becomes more active and is once more moved in a 

 curve, as shown, to the upper point of the left-hand side, 

 where the slow downward movement once more begins. 



The process of laying one group of eggs and the corre- 

 sponding part of the ootheca occupies about four and a 

 half minutes, and, as each side is formed alternately, there 

 is an interval of about nine minutes between successive 

 repetitions of the same operation on the same side. (Actual 

 times measured were 9, 9, 9, 8, 7 minutes ; the times would 

 be less at the commencement and finish, as the ootheca 



TRANS. ENT. SOC. LOND. 1916. — PARTI. (AUG.) H 



