344 



MORPHOLOGY. 



203 



204 



The structure of the epidermis, and its development into pa- 

 pillae, hairs, &c., is very manifold. Development into surfaces 

 secreting nectar, both at the bottom of concavities and upon the 

 appendages, is especially common. The petals also occasionally 

 secrete a viscous substance, in consequence of which they adhere 

 together, as happens at the points of the inner petals of the 

 Fumariacece. I know of no other remarkable condition requiring 

 notice. 



I will here present merely a few examples of the forms described in 

 the foregoing paragraphs, exhibiting the tetra-merous, cruciate corolla 

 (fig. 200.), the bilabiate (fig. 201.), the tubular (fig. 202.), the papi- 

 lionaceous (fig. 203.), 

 and the many-leaved 

 cup-shaped (fig. 204.). 

 The development of 

 the regular corolla of 

 Passiflora princeps 

 is given in Plate 

 IV. 



From the multi- 

 plicity of its forms 

 and the variety of its 

 colours, the corolla has in all times at- 

 tracted attention, and so, from the earliest 

 period of the scientific study of Botany, 

 much, perhaps too much, relative stress 

 has been laid upon the knowledge of it, 

 whilst the other parts of the plant have 

 been comparatively neglected. That, in the 

 general destination of the vegetable world 

 to favour pre-eminently brilliant and varied 

 play of forms, and thus to become the richly 

 decorated garment of the geologically naked 

 and poverty-stricken earth, the organ espe- 

 cially devoted to the production of this wealth of form should express the 

 essential character of individual groups, genera, and even species of 

 plants, is of course to be expected ; but it is still even only a part of a 

 number of organs of equal importance, and in the scientific view of plants 

 the corolla must be considered even as a subordinate part, because we 

 are wholly ignorant of the laws of the production of form, and by giving 

 it a partial pre-eminence we should deviate most widely from our aim. 

 In General Botany there is particular necessity merely to indicate the 

 points of view from which one has to observe the infinite abundance 

 of specialities ; and this I have endeavoured to do in the paragraphs. 

 To go further into the structure of the corolla of particular groups I 

 consider to be a mistake, and in the highest degree confusing to the 



101 Lathyrus odoratus- Flower. A, a, Penta-merous coherent calyx, surrounding a 

 5-merous irregular papilionaceous corolla ; 6, upper petal (standard, vexillum) ; c, d, 

 and B, two lateral petals (wings, /) ; e and C, two lower petals, coherent at the 

 lower border (together the keel, carina). 



m Malva miniata. Flower, a, Three-leaved cpicalyx ; b, 5-merous coherent calyx ; 

 c, five-leaved corolla. 



