178 Mr. Griffith on the Ovulum o/'Santalum, 



occupied by a coniform mass of albumen, on one side of and beneath whici. 

 will be found the remains of the placenta and its stalk, now reduced to a flat- 

 tened body, covered with irregular cellular tissue. The embryo does not cor- 

 respond exactly to the axis of the albumen. (Tab. XVIII. fig. I2g.) Minor 

 changes consist in the growth of oblong, clavate cells from the surfaces of the 

 barren ovula, and probably in the absorption or breaking up of the tissue of 

 the nucleus of the fecundated ovulum. 



§ 3. Loranthus. 



The examination of several species of Loranthus has satisfied me that an 

 ovarial cavity does exist throughout the earlier stages of development, how- 

 ever obscure it may become subsequently, and that the ovula do exist before 

 fecundation has been effected. 



For the appearance of that cavity I refer to Tab. XX. fig. 1. of Loranthus 

 bicolor ; and as the subject requires revision, more especially regarding the 

 nipple-shaped process, represented as occupying the fundus, I shall content 

 myself with describing the ovula*, their relations with the pollen tubes, and 

 the changes consequent on the occurrence of these. 



In all the species I have examined the ovula consist of closed membranous 

 sacs, the upper extremity of which is rounded and generally dilated. Their 

 contents are grumous matter and some fluid, the former being generally 

 crowded in the head of the sac. (Tab. XX., Loranthus bicolor, figs. 4 and 5.) 

 The extent of these sacs is in all cases considerable, but still varies remark- 

 ably ; the variation appearing to be connected with a remarkable modification 

 in the situation of the albumen and of the embryo throughout the earlier 

 stages of its development. I have not in any instance hitherto been able to 

 observe that they had any definite relations with the nipple-shaped process of 

 the fundus. Their number is perhaps generally 6 ; and a transverse section 

 shows them to be arranged regularly enough round the obscure cavity in the 

 axis of the base of the flower. 



In one of the modification, above allnded to, of which Loranthus globosus, 

 Roxburgh, „ an .nstance, these sacs are confined to the part which is de- 



.uL- :;, h ;;re of these orala or the direction ° f their ^- « - - «**- «^, 



