LEAVES, ETC. 427 



Such cases as this hardly come under the head of mal- 

 formations. But where one part only of the leaf 

 is excessively developed, the other portion remaining 

 in its ordinary condition, there can be no hesitation in 

 ranking the phenomenon as teratological. 



Thus, Moquin says that the median nerve may be 

 prolonged beyond the blade of the leaf in the form of 

 a short strap or ribbon-hke excrescence, while, at other 

 times, the lateral parts of the leaf are subjected to 

 undue development. He refers to a case cited by 

 Schlotterbec^ in which each side of the leaves of a 

 yellow " violier" (wallflower) was dilated into a kind of 

 projecting lobe on either side of the true apex of the 

 leaf, thus rendering it in appearance three-lobed. M. 

 Delavaud^ puts on record a case of hypertrophy in the 

 leaves of the common elm, resulting in the formation 

 of an additional lobe and a return to the tricostate 

 type. . A leaf so affected is stated to have presented 

 the appearance of a fusion of two leaves. (See also 

 Multiplication of leaves, p. 353.) 



The hypertrophied and coloured leaf of Gesnera occu- 

 pying the place of the absent inflorescence has been 

 previously alluded to under the head of displacement 

 (p. 88). 



In some instances hypertrophy is the opposite of sup- 

 pression ; as in the case previously mentioned, where 

 the stipule in the inflorescence of a pea, which is usually 

 undeveloped and rudimentary, was developed in the 

 form of a leafy cup or pitcher. 



Another instance of the development of parts usually 

 suppressed, is afforded by the bud-scales of Magnolia 

 fuscattty which may sometimes be found with small but 

 perfect leaves projecting from them, the leaf in this 

 case being the lamina which is ordinarily abortive, 

 while the scales are the representatives of the stipules. 

 This condition is said by Hooker and Thomson (* Flora 

 Indica,' p. 73) to be constant in Magnolia CampbeUi. 



' " Sched. de Monat. Plant," in ' Act. Helvet..* t. ii, pi. i'i,.f. 14. 

 - " Bull. Soc. Bot. France,' vol. viii, 18fil, p. lU. 



