144 Johnson. — On Arceuthohium Oxycedri. 
In 1858 Hofmeister 1 described an ovarian cellular papilla 
in Loranthus enropaeus and in Viscum album. In each case 
he found the papilla lost its identity at an early stage by 
fusion with the surrounding tissue, the ovarian cavity becoming 
obliterated in the process. 
In 1859 Hofmeister 2 entered into much more detail as 
regards these two plants, and from his illustrations it is 
apparent that the ovarian papilla is far less pronounced in 
either plant than in A. Oxycedri. A whorl of three (often 
only two) embryo-sacs was observed, their position relatively 
to the carpels not being given. 
Of Viscum album Hofmeister says, ‘ The carpels soon come 
into contact with one another by their upper flattened sur- 
faces, leaving only a narrow intervening space. The group of 
very few cells at the bottom of this space must be regarded as 
the ovule of the mistletoe 3 4 . 5 Two to three embryo-sacs 
were found in a later stage, formed from cells beneath the, 
now, absent ovary. 
Hofmeister described a third form of the Loranthaceae, 
Lepidoceras KingiV , in which he saw a long free much atten- 
uated ovarian papilla having some three embryo-sacs in it at 
its base. 
In 1869 Van Tieghem 5 found it impossible, after repeated 
attempts, to observe any ovarian papilla in Viscum album , 
and came to the conclusion that it does not exist. Several 
embryo-sacs were found formed from sub-epidermal cells of 
the upper (ventral) surfaces of the carpels in their median 
plane. If more than one embryo-sac was formed for each 
carpel, they were still in its median plane and one above the 
other. Unfortunately the descriptions are not illustrated. 
1 W. Hofmeister, NeuereBeobachtungen iiber Embry obildung der Phanerogamen, 
in Pringsheim’s Jahrbiicher, i. 1858, p. 113. 
2 W. Hofmeister, Neue Beitrage zur Kennt. d. Embryobildung d. Phanerog. 
in Abh. der Sachs. Ges. d. Wiss., vi. 1859, p. 634, Plates I-IX. 
3 W. Hofmeister, op. cit. p. 555. 
4 W. Hofmeister, op. cit. p. 552. 
5 Van Tieghem, Anatomie des fleurs et du fruit du Gui, in Ann. Sc. Nat. 
xii. p. 101. 
