Mr. Griffith on the Impregnation q/'Dischidia. 395 



EXPLANATION OF PLATE XVIH. 



Fig. 1. Ovules of Dischidia Rafflesiana, Wall., with a portion of the placenta, at an early 



stage, magnified. 

 Fig. 2. The same, somewhat more advanced. 

 Fig. 3. An ovule, taken when the corolla is twice as long as the calyx ; the first appearance 



of the subsequent fissure, a, is now visible. 

 Fig. 4. The same, taken when the corolla is three times as long as the calyx; a, the more 



developed fissure. 

 Fig. 5. The same, taken when the corolla is half- developed ; a, the fissure, is now of consi- 

 derable size ; b, the grumous indication of a nucleus. 

 Fig. 6. A perfect ovule, before the application of the pollen-tube. 

 Fig. 7- An ovule, to which the pollen-tube has been attached for some time. The central 



excavation is now very distinct, and the grumous globular mass has disappeared. 

 Fig. 8. An ovule, with its boyau, showing the termination of the boyau within the fissure. 

 Fig. 9. A longitudinal section of the corona staminea and sexual organs of the same species, 



the floral envelopes being removed, with the exception of their bases, to show the 



course of the cord from the pollinia to the placentte. 



