DOUBLE FERTILIZATION IN COMPOSITAE. : 
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY. 
XXI. 
W.-). G. LAND. 
(WITH PLATES XV AND XVI) 
In August 1898, Nawaschin communicated to the Russian 
Scientific Congress at Kieff the results of his work on fertiliza- 
tion in Lilium Martagon and Fritillaria tenella. Guignard, upon 
learning of the discoveries of Nawaschin, contributed to the 
Academie des Sciences a short account of his unpublished 
researches upon fertilization in several species of Lilium. Miss 
Sargant, from a reexamination of her preparations of Lilium 
Martagon, fully confirmed the observations of both Nawaschia 
and Guignard. A recent study of Tudipa sylvestris and i Celst 
ana by Guignard gives results in strict accord with the earlier 
observations. 
These observers find that both male cells upon emerging 
from the pollen tube are vermiform and twisted on their pa 
* ; : e 
suggesting the idea of non-ciliated spermatozoids. One ™ : 
r atm 
cell, coming in contact with the egg nucleus, retains fo a 
its vermiform shape, gradually enlarges until it becomes ; 
spherical, and finally fuses with the egg nucleus. The — 
male cell fuses with the upper polar nucleus, and the muclets 
resulting from this fusion unites with the lower polar a 
Sometimes the polar nuclei fuse and then unite with the fuse 
cell, and sometimes the polar nuclei and the male cell aL 
simultaneously. Preparations of Lilium Philadelphi oe Ze 
tuigrinum in this laboratory show the last named condition. are 
_Sargant figures one case in which the ends of the male see : 
applied to the polar nuclei, uniting them as kes ga : 
. . + 48 . : 5 
Experiments in hybridization by De Vries and Corren roctoxst 
252 
Miss 
