"326 ERNKST WARREN. 



blood. In the inverted abdomen the fat-cells form a more 

 compact tissue running on each side, especially just above 

 aiid in the two longitudinal ridges which rest oti the elytra 

 (PI. XVI, fig. 19, ah. v.). There appears to be but little 

 coagulated blood in this portion of the body. Towards the 

 anal end of the abdomen there is a continuous^ thin layer 

 ■of blood lying immediately under the hypodermis of the 

 dorsal surface. In section it is seen that the median pro- 

 thoracic dilatation, the backgrowths of the metathorax and 

 tlie median swelling supported by tergum YIII are filled with 

 coagulated blood, but there may be an irregular strand of 

 •fat-tissue towards the middle of the cavities (PI. XVII, 

 figs. 32 and 33). There is a certain amount of fat-tissue iu 

 the metathoracic dorsal region (PI. XX, fig. 74), and there is 

 a fairly thick and continuous sheet nearly filling the space 

 between the huge mesenteron and the hypodermis of the 

 abdomen (PI. XVIII, and PL XIX, fig. 59,/. h.) 



Similarly in the female there is no excessive amount of 

 fat-body. The physogastrism is mainly due to the great 

 bulk of the genital organs and of the mid-gut. 



There is relatively more fat-tissue in Termitomimus, but 

 nevertheless Tragardh seems to under-estimate the effect of 

 the hypertrophy of the sexual organs in connection with the 

 physogastrism of this beetle. 



Trao'ardh states that in Termitomimus, where the cuticle 

 is thin and an endostracum is absent, there the hypodermis 

 may be very tenuous or scarcely discernible and is pressed 

 close to the cuticle by the underlying fat body. On the 

 ■other hand, where the cuticle is thick and an endostracum is 

 present there the hypodermis is thick and tends to be with- 

 drawn from the cuticle. 



In Paracorotoca there is no doubt that the thickness of 

 cuticle and the depth of the hypodermis tend to vary pari 

 passu, but the withdrawal of the hypodermis from the cuticle 

 and an accumulation of coagulable substance would seem to 

 depend primarily on the absence of pressure of the internal 

 •organs and not on the presence or absence of underlying 



