AUTHOH S ABSTRACT OF THIS PAPER ISSUED BY 

 THE BIBLIOGRAPHIC SERVICE, OCTOBER 27 



THE DIPLOID CHROMOSOME COMPLEXES OF THE 

 PIG (SUS SCROFA) AND THEIR VARIATIONS 



ROBERT T. HAXCE 



Zoological Laboratory, University of Pennsylvania 



TEN PLATES AND FIVE TEXT FIGURES 



CONTENTS 



I. Introduction 156 



II. Technique 158 



Preparation of tissue 158 



Counting ._ IGO 



Measuring 101 



Mechanical aids 101 



III. Acknowledgments 101 



IV. The chromosomes of the germ cells 102 



The diploid chromosome number 102 



The structure of the chromosomes 103 



A giant cell 104 



The reduced number of chromosomes 104 



V. The somatic chromosomes 165 



The chromosome number 105 



The range of number variation in the various tissues 1G6 



The chromosome number in uncut membranes 167 



The behavior of the 'extra' chromosomes 168 



The cause of the number variation 169 



VI. The metric analysis of the chromosomes 171 



Spermatogonia 172 



Total length of the chromosomes 172 



Pairs and relation of pairs 172 



Somatic cells 176 



Total length of the chromosomes 177 



Total length of the chromosomes in the various tissues 178 



The length of the chromosome fragments 178 



Discussion of the results of measuring the chromosomes 179 



The conditions in Oenothera scintillans 179 



The conditions in the pig 180 



A comparison of the conditions in the two forms 181 



The point of fragmentation 183 



155 



