ON CHORISIS. 381 



mens represents a single organ. The same is true of the organs seem- 

 ingly representing abortive clusters of stamens in Parnassia, and the 

 observation of Duchatre as to the development of the numerous sta- 

 mens of Malvaceae from small protuberances representing the single 

 stamens of the original circle may be confirmed by any one who will 

 examine with attention half-double Holyhocks in which intermediate 

 states are found between bunches of stamens and unfolded petals. 



The close bundles of stamens in Ricinus and the fan-like groups 

 in some Myrtaceae may be of the same kind. Admitting then, the 

 principle to a certain extent, we need not multiply examples. The 

 diflSculty is that, supposing the scattered parts of a vascular bundle 

 which forms the leaf to supply the filaments of a bundle of stamens, 

 we should anticipate the divided expansion giving only one cell to each 

 anther, as is the case in Malvaceae, but in other cases referred to we 

 have two-celled anthers resulting from the divided leaf, a real difficul- 

 ty without doubt, yet not sufficient, perhaps, to overcome the reasons in 

 favour of the theory. 



Transverse chorisis is quite a different thing and far more incredible 

 than what has thus far been discussed. The leaf of a Horse-chestnut, 

 a Virginian creeper, or a Lupin, occurs to us as a ready illustration of 

 the possibility at least of collateral chorisis, and it being satisfactorily 

 proved that an ordinary stamen is but a leaf developed under peculiar 

 circumstances, a leaf becoming a group of connected stamens cannot 

 seem entirely opposed to our reason, each portion of the leaf has its 

 own vascular bundle to form the filament and its own cellular expan- 

 sion to form the anther. But when we are told of that which is but a 

 thin lamella of organized substance, with its two surfaces differently 

 constructed, and its intermediate portion quite distinct from both, 

 splitting in planes parallel with its surface so as from the one 

 to produce a number of similiarly expanded organs possessing the 

 same general structure as the undivided organ would have done, we 

 may well exclaim against the extravagance of such an assumption, and we 

 try in vain to think of any thing which appears to justify it. A carpel 

 is but a leaf in a peculiar state of development, and as it advances 

 towards maturity as«a fruit, we can often separate in a direction par- 

 allel with its surface three portions, the epicarp or outer surface, the 

 mesocarp or vascular and intermediate portion, and the endocavp, the 

 inner lining of the fruit corresponding to the upper surface of the 

 ordinary leaf ; but these three parts though often separable in factj, 



