134 Field Museum of Natural History — Reports, Vol. IV. 



labels were provided for these birds and a large number of new labels 

 was placed also in the serial exhibition of mammals. Considerable 

 time was devoted to the work of reinstalling a portion of the bird 

 collection. In spite of many interruptions the regular work of 

 pinning and labelling entomological material was continued as usual, 

 and 1,119 specimens were prepared. A number of daj^s was given to 

 showing specimens to scientific visitors and teachers with their classes. 

 The services of the assistant, Mr. Wolcott, were largeh' utilized in 

 drawing maps and other illustrations for use in the publication on 

 Mammals of Illinois and Wisconsin (now in press). Aside from the 

 work of pinning and installing insects, experimental work was under- 

 taken in preserving or reproducing insect larvae for proposed exhibition 

 groups. The two forms to which the assistant gave the most atten- 

 tion were the Cecropia and the Polyphemus moths. The eggs, larvae, 

 and cocoons of these specimens collected during the fore part of the 

 summer, and subsequently the various breeding stages, were utilized 

 in order to illustrate the life history of these insects. After making 

 a number of experiments on the immature stages of these species, 

 it was found necessary to reproduce the larvae in wax, using, however, 

 also parts of the original specimen, such as the head, feet, spines, etc. 

 For the branches which are to contain the larvae there have been made 

 over four hundred and fifty wax leaves. Although the wax is much 

 in the nature of a new undertaking, and although some important 

 problems have not yet been solved — the preservation of hairy cater- 

 pillars, for instance — still the results are so promising that it is hoped 

 to continue the work. During the year the work in the Division of 

 Osteology has progressed favourably, a great deal of time being devoted 

 to cleaning skulls for the study and exhibition series. A valuable 

 acquisition to the Museum was a fine skeleton of the extinct Great 

 Auk, Plautus impennis, which was skilfully mounted for exhibition by 

 Assistant Curator Gueret. The degreasing plant at Whiting, Indiana, 

 still being at the disposal of the Museum, ^7, skeletons and skulls of 

 mammals, birds and fishes were degreased during the year, also a 

 large iTiounted Tarpon. 



PRINTING. — The number of labels and the impressions made by this 

 section is as follows : 



Department of Anthropology 



Department of Botany 



Department of Geology 



Department of Zoology 



Director's Office 



