Johnson. — On A rceuthobium Oxycedri. 145 
In 1881 Treub 1 * began his ‘ Observations sur les Lorantha- 
cees,’ the first species described being Loranthus sphaerocarpus. 
In this he found an ovarian papilla with several apico-lateral 
slightly projecting lobes on it. This papilla, like that found 
by Hofmeister in Loranthus europaeus , soon fuses with the sur- 
rounding tissue, causing the gynaeceum to appear in section as 
a solid body composed of vertical continuous columns of cells, 
each originally distinct lobe of the papilla being now repre- 
sented by an elongating embryo-sac. In forms still more 
recently examined, Viscum articulatum 2 and Loranthus pen- 
tandrus 3 , Treub found no ovarian papilla, though in the 
last-mentioned species there was a slight indication of a 
tendency to form one. 
3. Morphological value of the Ovarian Papilla 
AND ACCOMPANYING STRUCTURES IN LORANTHACEAE. 
Griffith purposely called the papilla in Viscum and in 
Loranthus bicolor a nipple-shaped process in order to leave 
open the question of its morphological nature. He would go no 
further than to say he regarded this process as a placenta, and 
the two projections on it in Viscum as naked ovules. He 
regarded the condition in the Loranthaceae as an extreme 
reduction of the free central placenta with ovules of such an 
angiosperm as Primula , an intermediate stage being exhibited 
by the Santalaceae. 
Hofmeister regards the papilla in the plants in which he 
found it as a free naked orthotropous ovule containing several 
fully developed embryo-sacs. 
Professor Oliver’s opinion as to the nature of the papilla 
in Arceuthobium cryptopodum has been already quoted (ante, 
p. 141). 
Baillon says of A. Oxycedri , ‘ The papilla is an ovule, 
erect, orthotropous, and comparable to the nucellus of Poly - 
1 Treub, in Annales du Jardin Buitenzorg, ii. i i9rae partie, p. 54, Plates VIII-XV. 
3 Treub, in Annales du Jardin Buitenzorg, iii. i i9me partie, p. 1, Plates I— II. 
3 Treub, in Annales du Jardin Buitenzorg, iii. 2 [ ° ia0 partie, p. 184, Plates 
XXVIII-XXIX. 
