CONTENTS 



PAGES 



1. Studies in Juglans I: Study of a New Form of Juglans Calif ornica 



Watson, by Ernest B. Babcock 1- 46 



2. Studies in Juglans II: Further Observations on a New Variety of 



Juglans Californica Watson and on Certain Supposed Walnut-Oak 

 Hybrids, by Ernest B. Babcock 47- 70 



3. Studies in Juglans III: (1) Further Evidence that the Oak-like 



Walnut Originates by Mutation, (2) A Parallel Mutation in 

 Juglans Hmdsii ( Jepson) Sargent, by Ernest B. Babcock 71- 80 



4. Mutation in Matthiola, by Howard B. Frost 81-190 



5. Interspecific Hybrids in Crepis. I. Crepis Capillaris (L.) Wallr. x C. 



Tectorum L., by Ernest B. Babcock and Julius L. Collins 191-204 



6. Inbreeding and Crossbreeding in Crepis Capillaris (L.) Wallr. I, 



by Julius L. Collins 205-216 



7. Inheritance of Some Morphological Characters in Crepis Capillaris, 



by Venkata Eau 217-242 



8. Microsporogenesis of Ginkgo Biloba L. with Especial Reference to 



the Distribution of the Plastids and to Cell Wall Formation, by 

 Margaret Campbell Mann 243-248 



9. Inheritance in Crepis Capillaris (L.) Wallr. III. Nineteen Morpho- 



logical and Three Physiological Characters, by J. L. Collins 249-296 



10. Chromosome Number and Individuality in the Genus Crei^is. I. A 



Comparative Study of the Chromosome Number and Dimensions 



of Nineteen Species, by Margaret Campbell Mann 297-314 



11. Chromosome Number and Individuality in the Genus Crepis. II. The 



'Chromosomes and Taxonoraic Eelationships, by Ernest Brown 

 Babcock and Margaret Mann Lesley 315-341 



12. Chromosomal Chimeras in Crepis, by Lillian Hollingshead 343-354 



13. Chromosome Numbers and Morphology in Trifolium, by Haakon 



Wexelsen - .- 355-376 



14. Studies on Polyploidy. I. Cytological Investigations on Triploidy 



in Crepis, by M. Navashin 377-400 



15. Meiosis in Two Species and Three Hybrids of Crepis and Its Bear- 



ing on Taxonomic Relationship, by E. B. Babcock and J. Clausen. 401-432 

 Index 433-438 



