BRITISH MUSEUM (NATURAL HISTORY). 107 



growth, the age of the fish being determined by the number 

 of rings on the scales, a series of which is exhibited to illus- 

 trate the method. Also a series of the young of the Eel, and 

 a map to show the position of the breeding ground in the 

 Atlantic Ocean, and the points reached by the eastwardJy- 

 migrating Elvers in different months of the year. 



Much work has been done in the way of re-mounting and 

 re-spiriting such of the anatomical preparations in the 

 Entrance Hall as were in need of attention. 



The models and casts of the Deep Sea Fishes temporarily 

 exhibited in the Entrance Hall are now displayed in a 

 horizontal table-case in the Fish Gallery, with an introduc- 

 tory label explaining the general characters in which deep 

 sea fishes diff'er from other fishes. 



Economic Zoology. 



The work in connection with this section has had reference 

 chiefly to insects. The questions submitted have mostly been 

 from medical men abroad who are investigating the spread of 

 disease by the agency of insects, and also from persons who 

 ask for the names of pests, or for advice as to the best method 

 of destroying them. 



The following are some of the subjects of inquiry : — 



(1.) "The Nimetta or jVemetti Fly " of Dongola, sent 

 from Khartoum for identification, with the note 

 that " Besides biting, the flies are an intolerable 

 " nuisance through getting into the nose and 

 " eyes, causing all work to be suspended." The 

 species proved to be Simulium griseicollis. 

 (2.) Inquiry whether Glossina ijal-palis, one of the 

 Tsetse Flies, occurs in S. Africa, and whether 

 any other species of Glossina has been shown 

 to carry Trypanosoma gambiense. And from 

 another correspondent, whether Glossina pal- 

 palis is limited by altitude and always lives in 

 close proximity to large rivers and lakes. 

 G. palpalis does not occur in S. Africa, and 

 even G. morsitans is not found south of St. Lucia 

 Lake. At time of writing no species of Glossina 

 other than G. p)alpalis had yet been proved to 

 carry Trypanosoma gambiense, but since there 

 is reason to believe that several species of 

 Glossina besides morsitans can carry Trypano- 

 soma brucei, it is quite possible that G. palpalis 

 is not the only species capable of conveying 

 T. gambiense. All available evidence goes to 

 show that Glossina palpalis is only found in 

 close proximity to water (which may, however, 



