108 



PRINCIPLES OF PLANT-TERATOLOGY. 



Thomas, A. P. W.— "The Affinity of Tmesipteris with the 

 Sphenophyllales." Proc. Roy. Soc., vol. Ixix (1902), 

 pp. 343-350. 



Tidestrom. — " Note on Botrychium virginianum (L.) S. W." 



Torreya, vol. v (1905), pp. 160-162. 

 Velenovsky. — " Vergleichende Studien iiber die Salix-BlUte" 



Beih. Bot. Centralbl., Bd. xvii (1904), part 1, pp. 123- 



128. 



Witte. — " Ueber abweichende Zahlenverhaltnisse und einige 

 andere Anomalien der Bliithen der C. rotundifolia L." 

 Ark. Bot., Bd. iv (1905), Hafte 4, 8 pp., 1 pi. 



Worsdell. — " The Morphology of the Flowers of Cephalo- 

 taxus." Ann. Bot., vol. xv (1901), pp. 637-652, pi. xxxv. 



5. DIALYSIS. 



This term has been usually applied to the dissociation 

 of members belonging to the same floral whorl which 

 are normally coherent. It is here, however, in tended 

 to apply it also to the abnormal dissociation of members 

 belonging to different whorls; and the two cases will 

 be taken together. 



It is generally recognized that the dialyphyllous 

 condition is more primitive than the gamophyllous, for 

 the former is characteristic of those orders which in 

 other respects are considered the more primitive ; wdiile 

 those which exhibit gamophylly are for the most part 

 more advanced. As an example from each group 

 respectively may be mentioned the Ranunculacese and 

 the Campanulaceae. Hence it may be here at once 

 stated that all cases of dialysis affecting any given 

 floral whorl are reversions to a more ancestral state. 



(1) Calyx. 



Gamosepaly and gamopetaly are nearly always 

 associated; and where dissociation of the petals occurs 

 in a gamopetalous flower it is generally at the same 

 time accompanied by dialysis of the calyx. This occurs 

 now and again in a good many plants. Masters 



