Report of the President. 29 



stomach of a young deer. The entire organ has preserved its 

 natural shape; the characteristic glandular tissue of the 

 rumen is evident; the cellular tissue of the reticulum is 

 distinct; the muscular layers of the psalterium are readily dis- 

 tinguished, and the blood vessels have retained their natural 

 color. 



A modification of the same method has been extended to 

 the preparation of osteological sections. The specimens are 

 in every way clean and attractive, showing the structure of the 

 bone and the joint with clearness. 



Dr. C. W. F. Muenchehofe has begun a series of corrosion 

 preparations of the liver and kidney, which are already prom- 

 ising excellent results. He has also instituted a tentative 

 bacteriological demonstration showing the typical growth of 

 many chromogenic, pathogenic and useful bacteria, which, when 

 completed, will make an instructive display. 



Acknowledgments should here be extended to the Director 

 of the Aquarium, the Director of the New York Zoological 

 Society and the Director of the Central Park Menagerie, for 

 many courtesies received. 



Department of Preparation and Installation. — The 

 Department of Preparation and Installation was established 

 at the beginning of the year 1903 for the purpose of coordi- 

 nating some of the more or less similar classes of preparatory 

 work required by the various departments of the Museum and 

 up to that time performed by each of them separately. The 

 function of the new department thus' became the preparation 

 of various material for the respective study collections and 

 particularly for purposes of exhibition. 



Besides this, its primary object, there has been developed 

 in the department, under Dr. B. E. Dahlgren, a line of 

 Museum work not heretofore seriously attempted in this 

 country — the preparation of biological models. During the 

 short time of its progress this work has been carried on 

 along such lines as the needs of the synoptic zoological exhibit 

 required, and a considerable number of forms have been 

 modeled as follows: 



