188 Mr. Griffith on the Ovulum o^ Santalum, 



especially towards its termination, has a remarkable tendency to ramification. 

 It is to be observed, also, that towards its point of growth it always seems to 

 present minute molecular matter. 



In Osyris this sac has presented to me uniform appearances, and is more 

 satisfactorily observed from the extension backwards appearing to be gene- 

 rally confined to one ovulum. 



In Santalum, whenever the protrusion is observed in the expanded flower, 

 the extension backwards also presents itself. I have not observed any striking 

 differences in length, size, &c, between those of the barren and fertile ovula. 

 Its study is also obscured by its tendency to branching, which I have remarked 

 within the nucleus itself; nor have appearances been altogether wanting to 

 suggest to me the probability of the occasional union of two at least of the 

 tubes into one. 



In both genera the appearances of the protruded parts are uniform. Two 

 striking exceptions were observed in Santalum, in which two tubular portions 

 originated from one bulb ; and in one case both were completely developed, 

 suggesting the possibility, as is also pointed out by the posterior branching, 

 that one embryonary sac may be so modified as to produce several compara- 

 tively independent embryos. 



On the exact structure of the apex of the sac (in Santalum) in its mature 

 state I have no direct observations to offer. I believe that the appearances 

 are due to the presence of from 3 to 5 cells attached to the simple apex of 

 the sac; but whether these cells are derived from the placenta, or whether 

 they belong more properly to the sac itself, I am quite ignorant. The ten- 

 dency to adhesion to the placenta, the appearance of these cellular teeth, and 

 their not appearing to originate from the extreme apex, may perhaps be taken 

 into consideration as arguing their placentary origin. 



The contents of the sac in Osyris appeared to me minutely molecular, and 

 to have agreed with the contents of the ends of the posterior extensions of 

 Santalum. In Santalum, with similar minute molecular matter, granules of 

 various sizes, often very large, occur, both being endowed with mobility. 

 Iodine colours the mass of contents, before the application of the male influ- 

 ence, violet-blue; this is especially evident where there is any aggregation of 

 granules, for there is even at this time a tendency to a fuscous colouring in 



