VOLUME XLIII NUMBER 2 
BOTANICAL. CA7eI Te 
FEBRUARY 1907 
POLLEN DEVELOPMENT IN HYBRIDS OF OENOTHERA 
LATA XO. LAMARCKIANA, AND ITS RELATION 
TO MUTATION: 
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 
LXXXIX 
REGINALD RUGGLES GATES 
(WITH PLATES I-IV) 
This paper is a record, in part, of some investigations upon 
DeVries’ mutants of Oenothera. The work was begun at the 
Marine Biological Laboratory, Woods Hole, Mass., in the summer of 
1905; continued in the Botanical Laboratory of McGill University 
during the year 1905-6; and again at Woods Hole in the summer of 
1906, where a larger garden of evening primroses was grown and 
Studied, and material collected for further work; which is now being 
prosecuted at the Hull Botanical Laboratory, University of Chicago. 
( T have to thank Dr. B. M. Davis, under whose careful guidance the 
Tesearch was begun, for much attention and many suggestions and 
i criticisms. I also have pleasure in acknowledging my indebt- 
edness to Professor D. P. PENHALLOW, McGill University, for 
| Placing all the facilities of the Botanical Laboratory at my dis- 
Posal, and for many kindly suggestions, to which Assistant Pro- 
Te fessor Carrie M. Derick also contributed, as the work progressed. 
pe Phe investigations at Woods Hole were carried on with the aid of 
olarships from McGill University. I have to thank Dr. GEORGE 
T. Moore for encouragement in the work of last summer, and also 
” TA preliminary paper was presented before Sections F and G of the American 
. Association for Advancement of Science at New York, December 28, 1906. 
i 81 
