68 



Double Petunias 



TABLE IV. 



Showing that doubles do not occur when the singles derived from a cross with 

 a double are either self-fertilised, or crossed with other singles similarly 

 derived. 



Form of union 



Single 



seed-parent 



(single H x double H) 



Single 



pollen-parent 



self 



(^■x double H) 

 »> 



>» 

 (single HxN)x double H 



>> 

 (single H x double H) 



(single H xN) X double H 

 (single H xN)x double H 



self 



self 



(single H x double H) 



(single HxN)x double H 

 N X double (NxH=si, double) 



* A double which occurred in this batch was evidently a rogue as the flower had some 

 of the characters of nyctaginifiora. 



EXPLANATION OF FIGURES. 



I am indebted for the accompanying figures to Miss D. F. M. Pertz, to whom I here 

 tender my best thanks. 



Fig. 1. Single flower seen split longitudinally. 

 Fig. 2. Usual type of double flower showing extreme petalody, seen from above. The 



functional stamens are concealed by petaloid structures. (See next figure.) 

 Fig. 3. Similar flower seen in longitudinal section. 

 Pig. 4. Less common type of double flower. Stamens numerous, but supernumerary 



petaloid structures few and small. The corolla tube is curiously folded so as to 



form a kind of cup round the stamens. (See next figure.) 

 Fig. 5. Same flower in longitudinal section. Between the lower region of the corolla tube 



which rises vertically, and the upper part which lies horizontally is seen the curious 



double bend which forms the cup-like structure surrounding the stamens. The ovary 



is aborted. 

 Fig. 6. Group of stamens and a small supernumerary petaloid structure belonging to 



the same flower showing fusion for some distance above the point at which they 



become free from the corolla tube. 

 Fig. 7. Two stamens showing prolongation of the connective. 



