Mr. Griffith on the Ovulum ©/"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. 



Tab. I. 



Fig-. 1. Represents the obtuse placenta from a flower-bud J 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, f 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 (frds 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. 



h,b,h,b. The upper portions of these prolongations, which terminate 

 in cul de sacs, and contain, as it appears, at least with a small magni- 

 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 ex- 

 ceedingly fine filaments are visible attached to the apex of the 

 placenta, and to the corresponding parts of the tubular membranes. 

 The molecules have become aggregated, and appear to form (in the 

 right hand ovule at least) a grumous opake line of communica- 



VOL. XVIII. K 



