BRITISH MUSEUM (NATURAL HISTORY). 8 7 



0£ the progress o£ Index Museum work for the current year 

 (1919), the following is a summary : — A model of the Human Body 

 Louse (Pediculus humanus), enlarged 100 diameters, has been placed 

 on exhibition in the Pathogenic Insect case in the Central Hall. 

 This model is of special interest, as the late war has shown the 

 Louse to be the disseminating agent of Trench Fever, as well as of 

 Typhus, and of European Relapsing Fever. It is intended to add 

 to the case other enlarged models of the adult mouth-parts, and of 

 the eggs and larva respectively. 



A general dissection of a young Porpoise (Phoccena pJioccena), 

 showing the skeleton and viscera in situ, also the relationship of the 

 urinogenital organs to the vestigial pelvic bones, has been made for 

 Bay II of the Index Museum ; and an additional exhibit has been added 

 to the Mimicry Case in the form of the egg-cocoons of a Scale Insect 

 (Naiacocciis serpentinus), which closely resemble the droppings of 

 birds. 



Much time and thought has been given to the completion of 

 details for an index case dealing with the elements of structure in 

 Vertebrates generally, which is intended to form one of four table- 

 cases as an introductory series to Animals, Plants, and Rocks. 



All labels for this case are now in the printer's hands, and 

 certain additional preparations and drawings have been made ; so 

 that it is hoped that very shortly the final fitting up can be done, 

 and the case be duly exhibited in the Central Hall. 



The necessary work of re-camphoring all cases in charge of the 

 Index Museum has been undertaken. 



Sidney/ F. Harmer, 



Director, 



British Museum (Natural History), 

 1 April, 1920. 



