56 ACCOUNTS, ETC., OF THE BRITISH MUSEUM. 



pigeons with which they might be confused. The distinguishing 

 features of the various birds exhibited are explained in the labels 

 that accompany the specimens. 



During the month of May there was placed on exhibition a small 

 series illustrating the natural history of the worm Bilharzia (^Schisto- 

 somuni), that causes a disease of the bladder and rectum, known as 

 bilharziosis, common in Africa, the West Indies, and Japan. The 

 series includes actual specimens of the worms as they occur in the 

 veins of the intestine, and examples are shown of pond-snails which 

 are known to harbour the alternate generation of the parasites. The 

 life-history of the worm is explained by means of drawings of the 

 egg, and of the sporocyst and cercaria stages, and photographs of 

 bilharzia-infected canals in Egypt are mounted to illustrate how 

 the disease may be communicated to human beings by bathing or 

 standing in infected water. 



In consequence of the interest taken in the series of lice exhibited 

 under simple lenses in the Hall, the method of display has been 

 adopted in the case of three disease-spreading species of mosquitoes, 

 a flea, and two bugs. 



Further progress has been made in the introductory series of 

 animals, plants and rocks which, when completed, will be exhibited 

 in four table-cases in the middle of the Hall. The third case 

 (Invertebrates other than Protozoa) has been roughly planned out, 

 and some progress has been made in the preparation of the specimens 

 it is intended to display in the case. 



L. Fletcher, 



Director. 

 British Museum (Natural History), 

 24 February, 1917. 



