02 



HARDWICKE'S SCIENCE-GOSSIP. 



[March 1, 1869. 



ENCHANTER'S NIGHTSHADE. 



Circcea Lutetiana. 



By Majok Holland, R.M.L.I. 



THE Onagraeem, or Evening Primrose Order, of 

 which Cirraea is a genus, are in general tetra- 

 merous, the number four, or some multiple thereof, 

 prevailing throughout the floral organs. In Circeea, 

 however, the number is halved, there being but two 

 sepals, two petals, and so on : hence the plant is 

 distichous. In Lopa?zia still further degradation is 

 exhibited according to Lindley, "that genus show- 

 ing but one stamen ; in reality, however, there are 

 two stamens, one of them perfect and bearing an- 

 other, the other sterile and in the form of a spoon- 

 shaped petal." The two specimens of Enchanter's 

 Nightshade represented in the figures which illus- 

 trate this brief paper were gathered near Ivy-bridge 

 in Devonshire. 



The first, fig. 46, shows the normal flower, which 

 is binary in all its parts, having two sepals (1, 2), 

 two petals (3, 4), two stamens (5, 6), two lobes to 

 the stigma (7, 8), and two cells in the ovary. 



Fig. 4G. Normal Flower of Circcea Lutetiana. 



In the second, fig. 47, we have an abnormal or 

 monstrous flower ; a portion of the stigma is trans- 

 formed into the anther of a stamen, and one of the 

 stamens assumes the character of a petal, while in 

 the place of one of the petals we have two distinct 

 sepals: thus four distinct sepals are displayed instead 



of two. This instructive monstrosity seems to dis- 

 close a tendency in Circsea to revert to the tetra- 

 merous type. In the normal flower each of the two 

 deeply-cleft petals appears to be formed by the 

 coalescence of two coralline leaves, but there are 

 only two sepals, and they present no corresponding 

 indications of coalescence. 



Fig;. 47. Monstrous Flower of Circma Lutetiana. 



In the two figures the corresponding numbers ex- 

 press homologous parts. 



The beautiful doctrine of the metamorphosis of 

 the leaf is illustrated in the retrogression of one 

 member of each of the three internal whorls of the 

 floral organs to the grade next below it. In the 

 common doubling of roses, stamens by simple retro- 

 grade development become petals, perhaps display- 

 ing a metamorphosis in one whorl only ; but in the 

 specimen of Circsea before us three of the floral 

 organs are thus affected. 



Ou comparing the monstrous with the normal 

 flower, we find one lobe of the stigma converted 

 into an anther, one of the anthers into a petal, and 

 one of the petals into two distinct sepals (3), the 

 latter further affording undeniable proof of the 

 composite structure of the normal petal, otherwise 

 iudicated by its emargination. 



I was not aware until after I had written these 

 few lines on this interesting subject that the late 

 Professor Edward Eorbes, to whom the original 

 specimens from which these drawings were made 

 were presented, was so much struck by the lessons 

 they conveyed that he caused diagrams to be pre- 

 pared from them for the botanical classes of King's 

 College. 



Bury Cross, Gosport. 



