EANSACTI 



OF 



THE LINNEAN SOCIETY 



4 



i 



t 



I. A Contrihtdlon to a Knowledge of the Ilutating Oenotheras. By Reginald R 



Gates, M.A., Th.D.; Boijal College of Science, South Kensington. {Communicated 

 by Prof. J. Bretland Parmek, F.B.S., F.L.S.) 



(Plates 1-6.) 



Eead 7th November, 1912. 



Contexts. 



Page 



I, Introduction • 1 



II. Conspectus of Species and Mutations of the Onagra group of Oenothera 11 



Key to Oenothera species of the Onagra group 12 



III. Eelationships of Species 14 



IV. Variations and Mutations of 0. Lamarckiana^ Ser 20 



0. grandijlora^ Solander 38 



0. biennis, Linn 39 



0. muricata^ Linn -. 40 



V. (A) Cultures of Oenotheras from Lancashire 43 



(B) Cultures from Botanical Gardens 47 



VI, Hybridization in Oenothera • • 48 



50 



(a) Crosses involving 0. Lamarckiana and its Mutants 48 



{h) „ with 0. gigas 



(c) „ between 0. hiennis and 0. Lamarclciana and its derivatives 52 



id) Results ^^ 



VIL General Considerations and Summary 58 



VIII. Bibliography '. • • - ^2 



IX. Explanation of the Plates 64 



m. 



I. iNTEODrCTION. 



The purpose of tlie present paper is to bring together and organize certain results of 

 experimental work which I have carried on with the Oenotheras during the last six 

 years. My cytological work with tliese forms, which is already well known, will only 



SECOND SEEIES. — BOTAKT, VOL. VIII. 



B 



