TERATOLOGY 



1784 



known examples. The gall-gnats among the true flies 

 (Diptera) also produce a large variety of malforma- 

 tions, of which the eone-like galls resulting from de- 

 formed buds of the willow and the goldenrod are best 

 known. Plant lice (Aphidae) are responsible for the 

 large smooth red galls on the petiole of sumachs, and 

 for the flattish serrated galls on elm leaves. The fusi- 



2484. Dahlia leaf, illustratine the branchine of leaves 



form galls on stem of goldenrod and asters is caust 

 by the larva of a moth In t Iditirn t tine in it fl 



galls and 1. -.1 imII,,,, I 



stimulus ]!nH'|ih-l 



("poisons ■■) .-ii til. I I 1 I 



which case the gall del cl i_shi un 1 tl i g., s nietinu 



it is the mechanical stimulus due to movements of tl 



TERATOLOGY 



larva, together with the chemical stimul 

 rious excretions, in which case the gall 

 the hatching of the egg. 



5. Branching of leaves is 

 not infrequent, and its c 

 is uuknown. "Pour-leaved" 

 clovers offer well-known ex- 

 amples, and the normal num- 

 ber of leaflets is often in- 

 creased to six or eve 

 Fig. 2484 illustrates leaf- 

 branching in the dahlia. 

 Branching in the plane of 

 flattening, both in foliage 

 leaves and petals, has also 

 been observed, and the 

 branch described as an "out- 

 growth." 



G. Peloria. When usually 

 irregular flowers, such ns 



tho 



loria 



vith 



first observed 



(juris. Fig.248.5, and the term 



peloria, deriveii from the 



Greek word for monster, 



was given by him. Flowers normalHowers 



often become poloric on ac- peloria. 



2485. Toad-llax-Linaria. 



normal and ab- 



Exauiple of 



have been taken of it a 

 all spurs fail to develop. 



IIL TRANSFORMATIf)N 



more profound than iti'. 

 production of oru-.m 

 normally occupy tli. i 

 phosis. (The term miI- 

 present, because non-c( 

 causes.) It is common 

 retrogressiv? nietainorpl 

 but these terms involve 

 sumptions as tn tlio oriu 

 foliage leaves :iiid li.'r:il 

 which are ii"i insiiihili 

 the present si:ii.- ..f Ki 

 edge. Translornijitiiiiis i 

 chiefly in the r.-imi m1 

 flower, thouLrli tin y -.\v> 

 found exchisivrly tii.i.-. 



development of 

 leaves or leaf- 

 lets as tendrils 

 (Pig. 504); of 

 .sepals as petals; 

 and of petals as 

 stamens or pis- 

 tils. These 

 transformations 



.•rinses .•..ftr.inlv ......pcrate. A 



i-,.li;il ll.iu.i-s I,..., me zygo- 



■.M.ii...siitr«liintl .irollasof 



. -li.ilHil, as ill III,- cultivated 

 ims, but no notice seems to 



a malformation. Sometimes 



Figs. 248&-7. 

 OF Okciaxs: i. e., alterations 



or 



feet. O n the 

 other hand the 

 pistils and sta 

 mens often de 

 velop as petals 

 (Fi^ ■'(-) and 



1 h transformations, though other changes 



t 1 ite as noted above. Fig. 2488. Petals 



^ dc\ I ) as sepals, bracts, or even imperfect foliage 



ves while sepals and bracts frequently become foil 



