UNIVERSITY OF CALIFORNIA PUBLICATIONS 



IN 



AGRICULTURAL SCIENCES 



Vol. 2, No. 1, pp. 1-46, pis. 1-12 December 4, 1913 



STUDIES IN JUGLANS I 



STUDY OF A NEW FORM OF JUGLAN8 CALIFORNICA 



WATSON 



BY 



ERNEST B. BABGOCK 



CONTENTS 



PAGE 



I. History and description. 



First appearance and description of the original trees 2-5 



General appearance 3 



Leaves 4 



Nuts 4-5 



Recurrence of the new form 5—6 



Distribution under misleading names 7 



Name and botanical description 7-8 



Comparison with the species 8 



Summary 9 



II. Origin of the new form — hypotheses, observations, and experiments. 



Two discarded hypotheses 9-11 



First working hypothesis — hybridization 11-16 



Results of hybridization experiments 15 



Second working hypothesis — teratology 16-20 



Summary of evidence 19-20 



Third working hypothesis — mutation 21-23 



Summary of evidence 23 



