ACKNOWLEDGMENTS VH 



Maryland. These studies are being extended, but it is felt that the 

 information already at hand is sufficient for the purposes of this report. 



In my studies of the relationships and phylogeny of the species of 

 honey-guides I have been aided by information about the circulatory 

 system in several species kindly examined by Dr. F. H. Glenny and by 

 data on the jaw musculature furnished by Dr. W. J. Beecher. Dr. 

 Edward A. Chapin has made identifications of insect remains taken 

 from the gizzards of several honey-guides, and Dr. Ira B. Hansen has 

 kindly assisted by preparing material for microscopic examination. 

 At my request Dr. Charles Vaurie kindly made some X-ray photo- 

 graphs of the pygostyle of a spirit specimen of a lyre-tailed honey- 

 guide. 



For the colored plates, which enable me to bring to the readers of 

 this report the appearance in life of all the species of honey-guides, 

 thanks are due to the National Geographic Society for four of the five 

 plates; the fifth one was made possible by a special grant from the 

 John Simon Guggenheim Memorial Foundation. A word of apprecia- 

 tion to the artist, Walter A. Weber, for his painstaking and excellent 

 work in these five paintings must likewise be recorded here. 



