[Proc. Roy. Soc. Victoria, 31 (N.S.), Part 1 , 1918]. 



Art. II. — Teratologtcal Note. 

 Pentameky in a Flovvkr of Narcissus. 



By a. I). HARDY, F.L.S. 



[Read March 14th, 1918], 



In the specimen before us — " Narcissus tazetfa (" Soleil d'or," a 

 polyanthus Narcissus of the ** parvi-coronati " group) — we have an 

 inflorescence in which one of the flowers simulates a dicotyledonoua 

 bloom. It is the only one of the kind seen by me, although many 

 thousands of blooms were examined duiing the past spring season. 



The term ** doubling," as used by many gardeners, denotes mul- 

 tiplicity of any floral part, usually the petals, but by arithmetical 

 doubling we should have, in place of a flower with floral formula 

 (K3; C3; A3 + 3; G3) one with formula (K6: 06; A6 + 6; G6), a phenom- 

 enon explained as due to a splitting of the primordial papillae from 

 which the organs develop ; bwt instead of the formula indicative of 

 the simple type or its double, we have in the present specimen 

 (K5; 05; A5 + 5; G5). 



The size of the perianth lobes, or corona, relative position 

 of the whorls, length of ovary and perianth tube,^ and length of the 

 five stigmatic lobes are all normal. It is a ca,se of regular poly- 

 phylly ahecting — not the number of whorls, but the members only, 

 go that we may avoid the use of the comprehensive term, " positive 

 dedoublement " (of Celakovsky), which Worsdell'i perpetuates. But 

 the numerical increase of whorl members has resulted in a conspicu- 

 ously larger flower of which the coronal diameter is dispropor- 

 tionate to the diameter of the perianth; these compared with the 

 normal being respectively as [15 mm. : 7 mm.] and [35 mm. : 25 

 mm.] The corona shows no sign of division or dismemberment into 

 staminoid or petaloid units. The increased diameter of the flower is 

 due not to increased length of perianth segments, but to these parts 

 having been thrust farther out by the expansion of the perianth 

 tube (" zona perigyna ") to accommodate the increased number of 

 essential organ of fertilisation. These latter are so crowded in 

 the orifice of the tube as to choke it, and when the flower was fresh 



1. W. C. Worsdell, F.I^.S. " Principles of Teratoloj,^.v, Roy. Soc, 1916." 



