VEGETATIVE SPOKTS AND FLORAL FEEAKS. 



5 



disrected above, when the inflorescence is forming ; and on a hornbeam it 

 was observed that the branch-sport with "cut "leaves also bore inflor- 

 escences ; this coincidence shows that the cause of the change of form of 

 the leaf in these cases is due to the relaxation of the vegetative function, 

 on the arrival of the period of flowering.* 



Perforated Leaves. — These frequently occur when a severe spring has 

 checked the development of buds, so that when the leaves are unfolded 

 they are found full of holes and gashes due to starvation. These are not 

 reproduced without a similar cause. In many aquatic plants, degeneracy 

 has so affected them that they are normally more or less perforated, as in 

 our English pondweeds and the lattice-leaved plant of Madagascar. As 

 Monocotyledons appear to have had an aquatic origin ancestrally, many 

 terrestrial species of aroids have perforated leaves normally and heredi- 

 tarily ; but if such plants be cultivated in a rich soil, they more or less 

 disappear entirely. Conversely, horse-radish plants have large and com- 

 pletely formed leaves in a good garden soil ; but if they happen to grow 

 in an impoverished one, they are often deeply incised and resemble a frond 

 of the polypody fern. 



Crisped Foliage. — This is produced under the opposite conditions, 

 viz. of superabundance of nutriment. It is due to the fact that more 

 cellular tissue is "developed between the fibro-vascular cords than can lie 

 evenly, hence the margin appears crisped or the surface bulging. Such 

 may originate as a sport or by seed, but it is now hereditary, as in parsley 

 and savoy cabbages, &c. 



Floiuers : Multiform. — The fusion of two or more flowers into one 

 mass is not uncommon as a "monstrosity," and such is called " synan- 

 thic " : but a commoner sport is the " multiform " flowers, produced by a 

 multiplication of the floral organs, associated with a continuous branching 

 of the fibro-vascular cord, which normally is supplied to each sepal, 

 petal, stamen, and carpel respectively. This is extremely common in 

 strawberries ; but it has become hereditary in some cases, as the tomato, 

 and accounts for the numerous lobes to the fruit in the older forms. It 

 is not infrequent in the terminal flowers of herbs with irregular flotvers, as 

 the foxglove. This, too, has lately been proved hereditary, more than 

 90 per cent, of seedlings bearing the large tubular flower with a regular 

 border. A variety of forget-me-not, known as the 'Victoria,' has not 

 only a multiform flower, but fasciated stem, and both characters are more 

 or less hereditary. 



Crested Corollas. — A condition allied to the branching of fibro- 

 vascular cords of fasciated stems is produced in these corollas, but every 

 branch has its own cellular tissue, so that it stands freely out from the 

 surface of the petal. It has occurred in the cyclamen, daffodil, and 

 begonia. It is of the same nature as in outgrowths from the ribs and 

 veins of cabbage-leaves.t These outgrowths sometimes assume the form 

 of cups, funnels, or miniature leaves : they then exactly resemble 

 certain forms of degenerate ovules, which also grow out from the margins 

 of carpels in connection with fibro-vascular cords in precisely the same 



* For further details the reader is referred to The Origin of Plant Structure 

 p. 247. 



f This variety was described and figured by Gerard e in his " Herbal," 1597. 



