Osyris, Loranthus and Viscum. 173 



the deflection of the posterior extension of the sac in the direction of the axis 

 of the placenta, and in the appearance of cellularity and division of the apex. 

 The contents likewise appear to undergo some changes, but these are limited 

 to the apex, and seem to consist of a sort of condensation, and irregular and 

 variable division, of the grumous matter. 



At the period of expansion of the flower, the posterior extensions will be 

 found to have reached nearly to the base of the placenta. Their terminations 

 in this direction are in culs de sac ; there is a tendency to division and irre- 

 gularity of outline of all the included part, not even excepting that within the 

 ovulum itself. The contents seem, with the exception of the part within the 

 ovulum, to be chiefly grumous matter*, and this is again chiefly limited to 

 the termination. 



The apex appears at this period to have several (from 3 to 5) connivent 

 tooth-shaped lobes, divided, as it were, from each other below the middle by 

 rather conspicuous fissures. (Tab. XVII. fig. 1.) The contents, which are 

 grumous matter and largish granules, in the more perfect examples occupy 

 the whole of the apex, tapering below gradually into a line. The cavity of 

 the sac is at this time continuous, the contents passing on pressure freely 

 throughout. Iodine at this period causes the coagulation of the contents, 

 which then appear like a brown club-shaped coagulum studded with gra- 

 nules, the upper end of which is partially or entirely divided from the lower, 

 is much less or not at all granular, and is occasionally lobed and marked with 

 a line down the centre. 



At or about this time, if the bulb be examined, it will be found to present 

 traces of a convex septum towards its lower part, and very soon afterwards 

 traces of an additional septum, or perhaps cell of excessive fineness, are de- 

 tectible above this. 



The changes immediately incident on the application of the boyaux, which 

 may be traced upwards to the stigmata, consist in the appearance of a vesicle 

 within the apex, and the coagulation of the contents. 



The tubes which descend from the stigmata, and which are fairly, I think, 



* By grumous matter I mean that particular semi-opake, mucilaginous-looking matter, in which no 

 granules are detected, and which under the microscope resembles the appearance of a solution of gam- 

 boge. It has no proper form or distinction of parts. 



2 A 2 



