MALFORMATION. 740 MALFORMATION. parts arc lai"cr or of a different shape from the are a widely laiowu instance. (11) Pleimomery, othci-s souietlmes develop all the parts of like i.e. increase in the number c ■ • rr-l XI. „ ....II....- .ix.l i-if->iirra form and size. Thus the yellowand-orange flower of •butt<>r-and-eggs' or 'toadllax' lias usual- ly one spurred petal; but not infrequently all five of the petals become spurred, and the flower is then radially symmetrical. (Fig. 5.) A similar but reverse change occurs when flow- ers which arc radially symmetrical become un- svmmetrical, as whcii the tubular ray (lowers o"f the wild chrysanthemum or aster develop ligulate corollas." . This is quite as monstrous a form as the opposite, but has not been m- cluded among malformations. (10) Traiisfor- mation of floral parts is extremely common. of any group of or- FlQ. 6. CEI6PATE LEAF OF LETTFCF,. Thus sepals, normally green, may grow into petal-like form and color; while petals may take the shape and function of stamens and pis- tils. Transformati(m of this sort, that is, from a less specializ<'d into a more s])ecialized organ, is not so frequent, and the organs are usually very im])erfect. Transformation in the other direction, that is, from specialized to less spe- cialized organs, is so common that they are scarcely thought of as malformations. Thus pistils and stamens may develop as petals, a transformation which occurs in most double flowers ; petals may be transforined into sepals, or even into imperfect foliage leaves. Indeed, all parts of the flower may be developed as irregular green leaves, of which the so-called 'green roses' Fig. 7. LEAF OF HICKORY. Showing abnormally branched terminal leaflet. gans, occurs most commonly in the floral regions. Some double flowers owe their origin purely to this plienomenon. The increase may affect the ntimlicr of parts in a whorl, or the n u m b e r of whorls. In the Ba- hia or navel orange an additional num- ber of carpels is reg- ularly produced, and an imperfect fruit develops, inclosed by the larger one. The so-called 'two-story apples' have their origin in a similar change. Occasionally the additional car- pels are lateral to the others, in which case an imperfect fruit may be devel- oped alongside the more perfect one. Malformations dif- fer strikingly from galls in the process of their formation, which is due to in- trinsic causes, where- as galls result from ^^^ ^^^^^.^^ ^^^^^^ ^, p,^„^^.„ some extrmsic cause abnormall.T branched ; thi> nor- such as the presence mal inflorescence is formed of in the plant tissues crowded single flowers, of insects, mites, worms, fungi, slime molds, etc., or from the secretions of these crea- FlG. 8. ABNORMAL BRANCHING.
