458 ABORTION 



partially developed only, and forming a kind of cup, 

 from which the true carpels protrude. 



Abortion of the leaves. Arrest of growth in the leaves 

 occurs in different ways ; sometimes the whole leaf is 

 smaller than usual; at other times certain parts only 

 are reduced in size ; while, in a third class of cases, 

 portions of the leaf are entirely suppressed. 



JVIoquin^ mentions having seen the leaves of Cheno- 

 podium vulvaria, and of Dixdotcuns muralis reduced to 

 a fourth of their natural size ; and he alludes to other 

 cases of the same nature, seen by other observers, in 

 Hypericum perforatum and Blitmn polyiiKyrphum. 



Nicandra physaloides^ has also been met with in a 

 similar condition, which, indeed, is a common result of 

 insect-puncture, and of fungous growth in plants. 

 Those instances in which the leaf is diminished in size, 

 without any attendant malformation in other organs, 

 may be regarded rather as variations than as monstro- 

 sities, as in the case of the entire-leaved varieties of 

 those plants which ordinarily have cut or divided 

 leaves, e.g. Plantago Coronojms, var. integrifoUa, Papaver 

 Blweas integrifoUa, &c. &c. The same remark may be 

 made of those specimens in which one part of the leaf 

 is developed to a less extent than another, as happens 

 in the submerged leaves of such plants as Ranuncidus 

 aquatilis, Cahomba aquatica, the spiney leaves of Berhe- 

 ris, the fenestrated leaves of Oumrandra, &c. In the 

 illustrations last cited the relative deficiency of one 

 portion, as contrasted with another, takes place as a 

 constant occurrence, and is uniform and regular 

 throughout the whole leaf. When, on the other hand, 

 the deficiency in question happens accidentally and 

 irregularly, the change may be considered as a malfor- 

 mation. One side of the blade of the leaf is frequently 

 affected in this manner, the other portions remaining 

 unaffected. It would appear as if any plant might be 



' ' El. Ter. Veg.,' p. 124. 



= Schlechtendal, ' Bot. Zeit.,' 1857, vol. xv, p. 67. 



