The Histology and Development of Cassytha 
Filiformis, L. 
(WITH PLATES XXXII, XXIV.) 
By Harriet Boewie, B. S. 
The order Lauraceae is composed of green shrubs or 
trees of independent growth and normal nutritive relations, 
excepting in the genus Cassytha, which is unique in the 
extremely reduced condition of its vegetative system and 
in its parasitic habit. The latter peculiarity has attracted 
the attention of several observers, who have carefully investi- 
gated the relation of the plant to its host. Comparatively 
little has been done to the histology, and apparently no effort 
made to trace the relation of the seed to the adult. 
It was mainly to complete the gaps in the history of this 
interesting genus that the present paper was undertaken, 
under the guidance of Professor Macfarlane, to whom I take 
this opportunity of expressing my indebtedness for the kind 
assistance he has at all times rendered me. The material 
for study was collected by him during the University’s expe- 
dition to Florida in December and January, 1900-Igo1 ; and 
from fruits collected on the spot, seedlings have grown suc- 
cessfully in the University greenhouses. 
The genus Cassytha is worldwide in its distribution in the 
tropics and sub-tropics. In habit it much resembles the 
stronger of our native Dodders, clambering over bushes so 
as to form masses several yards across. The color in hot, 
sunny exposures, as with Cuscuta Gronovit, is pale tawny 
yellow, but in shaded places it is of a rich dark green hue. 
All intermediate gradations were seen. The same plant on 
sunny and shady sides shows these differences most mark- 
edly. 
(399) 
