Osteological Collections 85 



save that of Mr. Paul Ruthling in Mexico, which was con- 

 tinued until October. Mr. Elwood Johnson spent 

 El eI< ! several months on the Atrato River drainage in 



Colombia and devoted all of his time to collecting 

 reptiles and amphibians. Local field work was continued 

 throughout the summer by various members of the Depart- 

 ment. A permanent file for local field observations has been 

 established, which will serve as a depository for field notes 

 made not only by the members of the Department but also 

 by other observers. 



A study of the bony and cartilaginous structures of reptiles 

 and amphibians presents many difficulties, especially because 

 of the small size and fragile nature of the mate- 

 Osteological r j a j Rapid strides have been made during the 

 year in perfecting a technique by which speci- 

 mens of any size may be depigmented, decolorized, and cleared 

 by a single process. Differential stains have been used with 

 success to bring out more clearly the bony structures. This 

 clearing method as now perfected is so much simpler, quicker 

 and more exact than the various skeletonizing methods that 

 there can be no doubt as to its future usefulness. During the 

 year, one member of the Department has cleared without 

 serious interruption to his other work forty-four salamanders, 

 three frogs, and fifty-seven lizards. The total expense of 

 clearing these hundred and four specimens did not exceed ten 

 dollars, which is about half the price demanded by most tech- 

 nicians for skeletonizing a single specimen. The great advan- 

 tage of the clearing over the dissection method is the absolute 

 freedom from loss, breakage, and disarticulation of parts. 



Four skeletons were prepared by the ordinary methods. 

 These will probably be used for exhibition. 



A new tray system for the storage of study material was 



inaugurated towards the close of last year, and the entire 

 amphibian collection is now installed in trays, 



c*\\ °L which facilitate rapid handling. The entire rep- 



tile collection has been checked over during the 



year and all the identified material on the storage shelves 



labeled. 



