50 Reginald R. Gates. 
distribution among the genera, families, and classes to which they 
belong. 
Note. —In order to avoid undue length a consideration of the 
other great sub-divisions of the plant kingdom is not entered upon 
here. Those readers who may he interested in such questions are 
referred to various memoirs in which they are discussed in detail; 
among others:— 
1. “ Distribution florale dans une portion des Alpes et du Jura.” 
2. “ Distribution de la flore alpine dans Ie bassin des Dranses, etc.” 
Bulletin de la Soe. vaud. Sciences naturelles, Vol. XXXVI 
Lausanne, 1901. 
3. “ Lois de distribution florale dans la zone alpine.” Ibid, Vol. XXXVII, 
1902. 
4. ‘‘Gesetze der Pflanzenverteilung.” Flora, 1902. 
5. “ Nouvelles recherches sur la distribution florale.” Bull. Soc. vaud. sc. 
nat., 1908. 
6 . 11 Apropos du coefficient generique.” Ibid, Proces-verbaux, Dec. 1908. 
AN ONAGRACEOUS STEM WITHOUT INTERNODES. 
By Reginald R. Gates, M.A., Ph.D. 
[Plates II and III]. 
I ~!OR several years I have been making analytical cultures of 
' CEnotheras from the sandy coast of Lancashire. These 
North American forms are known to have been naturalized in this 
locality for at least a century, 1 where they have long been growing 
in large numbers. Bailey 2 and MacDougal 3 were the first to show 
that these forms contain what are now known as O. Lamarckiana 
Ser., together with certain forms corresponding to some of the 
mutants of De Vries’ cultures, such as O. lata and O. rnbrinervis. 
In subsequent cultures of a more detailed character I have found 
1 Sec Sowerby’s English Botany, Vol. 22, pi. 1534, 1806. 
2 Bailey, Charles. “ De Lamarck’s Evening Primrose (CEnothera 
Lamarckiana) on the sandhills of St. Anne’s-on-the-Sea, North 
Lancashire.” Address to Manchester Field Club, January, 
1907. 
3 MacDougal, Vail and Shull. “ Mutations, variations and 
relationships of the CEnotheras.” Carnegie Inst. Pub. 
No. 81, 1907. 
