Mr. Grirrtra on the Ovulum of Santalum album. 65 
apex of the perianth, or the apex of the remains of the style. No dependence 
is, however, to be placed on mere measurement, since the development of the 
ovulum does not always correspond to that of the fruit. 
Tas. I. 
Fig. 1. Represents the obtuse placenta from a flower-bud $a line long, towards 
the base of which 2 ovula are visible; these are at this period papil- 
liform, and have no indications of distinction of coats or openings 
through these. 
Fig. 2. Ditto of a flower-bud, rds of a line long. The placenta is now elon- 
gated towards its apex. The ovula have assumed their mature form. 
There is still no trace of distinct coats, or of openings in them. 
Fig. 3. Ovulum detached, with a portion of the placenta, from a bud of about 
the same size ($rds of a line long). It is a cellular mass, somewhat 
truncate, the cells being most lax at the apex. It resembles in form 
and structure the nucleus of the ovulum of other plants. 
Fig. 4. Represents the placenta of a flower-bud about a line long. 
The placenta is still more elongated. Towards its base two ovula are 
visible, the corresponding two being necessarily concealed. a. Re- 
presents the part of the tube at its exit, and when its course is down- 
wards, nearly in the direction of the axis of the ovulum, 
b, b, b, b. The upper portions of these prolongations, which terminate 
in cul de sacs, and contain, as it appears, at least with a small es de 
fying power, grumous matter. These tubes are separated artificially 
from the placenta; they have not as yet completed their growth. 
Fig. 5. Placenta and ovula of a flower some time after expansion, and when 
the segments of the perianth have become of a dark blood-colour. 
Two ovula are seen in situ. The tubular prolongations from the 
bases of the ovula upwards to their apices are somewhat detached, 
owing to the object having been immersed in water. Several E. 
ceedingly fine filaments are visible attached to the apex E t , 
placenta, and to the corresponding parts of the tubular mem pet 
The molecules have become aggregated, and appear to form (in S 
right hand ovule at least) a grumous opake line of communica- 
VOL. XVIII. x 
