4.66 ABORTION. 
of a vine as becoming dry, and even dehiscing by valves 
like a capsule. 
In maize it occasionally happens that one or two of 
the longitudinal series of fruits become abortive, leay- 
ing a smooth furrow, at first of a greenish colour, but 
ultimately of a reddish yellow. Often a second row of 
fruits, opposite to the first, is also atrophied, so that 
the whole spike changes its cylindrical form for a flat- 
_tened one.’ See also under Heterogamy, Meiophylly, 
&e. 
Abortion of the ovules—In the case of a pluri-ovulate 
ovary it rarely happens that all the ovules attain to 
maturity, some never get fertilised, others, pressed on 
by their neighbours on either side, become impeded in 
their development, and finally disappear, or remain as 
rudiments.” This is the case, under ordinary circum- 
stances, and still more so in the case of hybrid plants, 
or of monsters. Where the outer coats of the ovule 
become more or less leafy in appearance (see p. 262), 
the inner investments become more or less atrophied, 
or are even more frequently entirely suppressed, as is 
also the nucleus. 
In other cases, a simple arrest of development takes 
place; the ovule, for instance, which should be ana- 
tropal, remains straight, while the integuments, checked 
in their development, form imperfect sheaths from 
which the shrivelled nucleus protrudes. 
Depauperated Ferns——The preceding illustrations have 
been taken from flowering plants chiefly, but a similar 
defective development is manifested in cryptogamous 
plants. The contraction and imperfect development 
of the fronds of some varieties of ferns, hence called 
depauperated, may receive passing notice, as also the 
cases in which the sori or clusters of spore cases are 
denuded of their usual covering, owing to the abortion 
1 Moquin-Tandon, ‘ El. Ter. Veg.,’ p. 325. 
2 Alph. De Candolle states that the position of the abortive ovules 
affords a good character for discriminating between certain species of 
Quercus. ‘ Bibl. Univ. Genev.,’ 1862, t. xv, p. 929. 
