Produced by Chris Curnow, Joseph Cooper, Josephine Paolucci and the Online Distributed Proofreading Team at https://www.pgdp.net. UNIVERSITY OF KANSAS PUBLICATIONS MUSEUM OF NATURAL HISTORY Volume 12, No. 13, pp. 553-573, 7 figs. March, 2, 1964 Thoracic and Coracoid Arteries In Two Families of Birds, Columbidae and Hirundinidae BY MARION ANNE JENKINSON UNIVERSITY OF KANSAS LAWRENCE 1964 UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY Editors: E. Raymond Hall, Chairman, Henry S. Fitch, Theodore H. Eaton, Jr. Volume 12, No. 13, pp. 553-573, 7 figs. Published March 2, 1964 UNIVERSITY OF KANSAS Lawrence, Kansas PRINTED BY THE STATE PRINTER TOPEKA, KANSAS 1964 [Transcriber's Note: Words surrounded by tildes, like ~this~ signifies words in bold. Words surrounded by underscores, like _this_, signifies words in italics.] Thoracic and Coracoid Arteries In Two Families of Birds, Columbidae and Hirundinidae BY MARION ANNE JENKINSON CONTENTS PAGE INTRODUCTION 555 METHODS AND MATERIALS 556 MYOLOGY AND ANGIOLOGY: HIRUNDINIDAE 557 Myology 557 Angiology 558 MYOLOGY AND ANGIOLOGY: COLUMBIDAE 560 Myology 560 Angiology 560 SUMMARY OF ARTERIAL ARRANGEMENT 562 DISCUSSION AND CONCLUSIONS 562 Individual Variation 562 Intrafamilial Differences 563 Interfamilial Differences 565 SUMMARY 567 LITERATURE CITED 573 INTRODUCTION Most descriptions of the circulatory system of birds, largely the work of Glenny, have dealt with arteries of the neck and thorax in a wide variety of species. As a result of his work, Glenny offered several hypotheses concerning the phylogenetic, hence taxonomic, significance of differences in some of these vessels. He also described six types of thoracic arterial arrangements and stated that these categories might represent various levels of evolution (Glenny, 1955:543-544). The families Columbidae (pigeons) and Hirundinidae (swallows) have two nearly extreme arterial types described by Glenny, and are universally acknowledged as monophyletic. Differences within the families, therefore, can be considered as valid intrafamilial differences. I have investigated the thoracic and coracoid arteries and their branches in members of these two families to determine the degree of individual variability of the vessels, and the possible causes of interspecific and intrafamilial differences. METHODS AND MATERIALS