ON THE DEVELOPMENT OF HAMAMELIS VIRGINIANA. 
CONTRIBUTIONS FROM THE BOTANICAL LABORATORY OF 
JOHNS HOPKINS UNIVERSITY, No. 3. 
D. N. SHOEMAKER. 
(WITH PLATES VI AND VII) 
INTRODUCTION. 
Tuts work on Hamamelis was undertaken on account of its 
peculiar habit of flowering. It is one of the few angiosperms that 
flowers in the fall and matures fruit the following year. This 
peculiarity made it seem worth while to investigate its entire embryo- 
logical history, and especially the behavior of the pollen tube and the 
time and manner of fertilization. The subject was suggested by 
Dr. D. S. JoHNson, to whom I wish to express my gratitude for 
sympathetic guidance and instruction during its prosecution. 
The literature of the family is not extensive, and none of it has 
to do with the embryology of any of its forms. The most complete 
working out of the anatomy and affinities is by REmNscH (12). Batt- 
LON (3) carefully described the organogeny of the flower in Ham- 
amelis virginiana and Fothergilla Gardeni. VAN ‘TIEGHEM (14) 
worked on the secretory canals of Liquidambar and Altingia. THOU- 
VENIN (13) described the structure of the root, stem, and leaves of 
various members of the family. The account given by NIEDENZU in 
Engler and Prantl’s Natiirlichen Pflanzenfamilien is the most com 
plete I have seen. 
In some American oaks, which require two years to mature seed, 
it has been found that fertilization takes place about a year after 
pollination. The statement is made by GOEBEL (15, P- 392) that 4 
period of rest occurs after the pollen tube has reached the embryo 
sac in Ulmus, Quercus, Fagus, Juglans, Citrus, Aesculus, Acer, 
Cornus, and Robinia. As Miss BENSON (4) points out, this sane 
ment is erroneous in the case of British Amentiferae. It is not true 
of Hamameli 
In Colchicum autumnale, according to HOFMEISTER (7), the pollen 
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