142 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



As regards Mutation in Coccidse. — E. Ernest Green {Trans. 

 Entomol. Soc. London, 1918, 149-54). That a reduction in the number 

 of antennal joints has been observed in South Indian specimens of 

 Lecaniwn {Coccus) viride and Fulvinaria psidii does not necessarily form 

 an argument in favour of the transmutation of the two species, but 

 suggests, rather, that a similar environment has induced in the two a 

 tendency to variation in the same direction. Green holds that the 

 genera Pidvmaria and Lecanium, though very closely allied, have quite 

 well-defined boundaries. He sees no more justification for regarding 

 L. viride and its allies as having been directly derived from P. psidii 

 than for assuming a similar, relationship between L. hesperidum and 

 P. Jloccifera, or many other pairs that might be mentioned. J. A. T. 



Study of Cockroach Head. — E. Bugnion {MT. Schwek. Entom. Ges., 

 1916, 12, 383-400, 1 pi., 4 figs.). An account is given of the structure 



"'' 6 5 4 3 2 



7 ^-.. N^ 



Sagittal Section op thb Head of Blatta americmia x 9. 

 (The mandibles and first maxillae have been removed.) 



Tongue. 2. Labrum. 3. Entrance to pharynx. 4. End of labro- 

 pharyngeal sinus. 5. Frontal ganglion, 6. Antennary nerve. 

 7. Section of optic nerve. 8. Sub-cesophageal ganglion. 9. Anterior 

 sub-intestinal ganglion. 10. Posterior sub-intestinal ganglion. 11. 

 Recurrent nerve. 12. Duct of salivary glands. 13. Duct of salivary 

 reservoirs. 14. (Esophagus. 15. Prothoracic ganglion. 



