" 180 Mr. Griffith on the Ovulum of Santalum, 



tubes do not reach any great length before they pass, as it were, into the 

 tissue of the young embryo, this never appearing to be altogether external to 

 the albumen even in its very young state. But in Loranthus globosus the case 

 is widely diflferent ; the continuations of the pollen tubes are greatly extended 

 before the proper tissue of the embryo appears to be developed. (Tab. XIX. 

 figs. 3 and 4.) In consequence of this extension, they assume a variously 

 bent or even contorted appearance ; for the sacs themselves being of the 

 same length as the cavities in which they are inclosed, and the tissues of 

 the base of the central part of the ovarium being dense and not admitting 

 penetration, the growths alluded to are necessarily disturbed in direction. 

 (Tab. XIX. fig. 4.) 



• At a variable distance in L. globosus, but almost immediately in L. bicolor, 

 the growths from the pollen tubes meet and become united, forming either 

 immediately or mediately the ground-work of one embryo (L. bicolor, Tab. 

 XXI. fig. 3 ; L. globosus, Tab. XIX. figs. 4 and 7) ; but it is proper to observe, 

 that in L. globosus, at least, a tendency towards separation of the growths of 

 the pollen tubes after junction is not unfrequent. (Tab. XIX. fig. 4,) The 

 same union affects the young albumina of both species, occurring however 

 earlier in L. bicolor. 



The embryo of L. bicolor presents nothing particularly worthy of notice in 

 its further evolution ; it presents throughout no great deviations from the 

 ordinary relations existing between albumen and embryo. (Tab. XXI. fig. 7.) 

 In L. globosus it is only at a late period that it becomes inclosed in the ordi- 

 nary manner in the albumen (Tab. XIX. fig. 4), through the constant ten- 

 dency of the embryo to be developed in a line with the axis, the pressure 

 opposed to it by the density of the tissues of the base of the flower, and the 

 extension downwards of the growth of the albumen. When mature, the 

 embryo presents its huge radicle projecting beyond the upper surface of the 

 albumen. (Tab. XIX. fig. 6.) I have to add, that in this species the deve- 

 lopment of the young albumen does not, for some time at least, affect the 

 appearance of the pollen tubes ; these may be seen, under pressure, in their 

 original form even when the albumen has reached to a considerable size. 



The above observations I consider as going no further than to establish the 

 existence of an ovarial cavity and of the ovula, independently of fecundation ; 



