156 



PRINCIPLES OF PLANT-TERATOLOGY. 



In a peculiar yellow-flowered variety of the potato 

 (a faint lilac and white tinge was also present), which 

 was investigated in Messrs. Sutton's seed-trial grounds 

 at Reading, the petals were all reverting to stamens, 

 their yellow colour being due to this fact ; in any 

 given flower one or more petals were connivent towards 

 the centre just like the normal stamens of all Solan- 

 aceae ; all five petals had vestiges of marginal pollen- 

 sacs, the ventral ones being absent, but represented 

 by several small ridges or inequalities on the upper 

 surface of the petal. 



Streptocaiyus has a habit sometimes of developing 

 as enations on the outer surface of the two posterior 

 petals two smaller petals with inverted orientation ; 

 occasionally, as in the flowers received from Mr. J. W. 

 Odell, these enations are in the form of stamens,* 

 more or less imperfect, and often showing transitions 

 to petals. 



Morphology of the Corona of Narcissus. — An oppor- 

 tunity has recently occurred of confirming the con- 

 clusions arrived at by Celakovsky (see infra) with 

 regard to the origin of the corona in Narcissus ; and 

 this in an unexpectedly interesting manner. Two 

 abnormal flowers of N. Pseudo-narcixsus var. tridymus 

 De Graaff were examinedf in which the three sepals, 

 the andrcecium, and the pistil were normal. But the 

 three petals were all partially transformed into 

 stamens, and it was owing to this fact that, as it so 

 happened, the nature of the corona became revealed 

 in its true light. In each case the corona of each 

 petal was bilobed, and it was confined to the petals, 

 the sepals being devoid of it ; as each petal had its 

 own individual corona it is obvious that the normal 

 corona had become split up. In both flowers the 

 corona of each petal was seen to be an intermediate 

 structure between a petaloid ligular outgrowth from 



* A fact which supports the view, set forth above, that such " enations " 

 really represent an extra whorl of floral leaves. 



t Obtained from Mr. Chittenden, hon. secretary of the Scientific Com- 

 mittee, R. Hort. Society. 



