1900] ‘DOUBLE FERTILIZATION IN COMPOSITAE 259 
The spermatozoid form of the male cell may be wide-spread 
inmonocotyls and dicotyls. In all the forms recently examined 
they have been reported as present, either in the pollen tube, in 
the embryo sac, or lying against the nuclei. In Lilium and 
Tulipa the male cells seem to assume the vermiform shape in the 
pollen tube, since in the microspore they are spherical. In Sil- 
phium they assume the elongated form in the microspore. 
At present double fertilization is known to be a fact in the 
Liliacee, There are indications that it will be found among 
the orchids, Among the dicotyls it has been found in Delpha- 
mum elatum, Helianthus annuus, and Rudbeckia speciosa. lt has 
also been doubtfully suggested in Juglans. The present paper 
adds to the list Erigeron Philadelphicus and Silphium laciniatum. 
The experiments of De Vries and Correns, and also of Web- 
ber, in hybridization of Zea Mays, indicate that we may confi- 
deatly expect double fertilization to be reported soon in that © 
Species, 
oo acknowledgments are due Professor John M. Coulter 
“eto Dr. Charles J. Chamberlain for assistance rendered dur- 
ing the Progress of the work. 
THE UNIversiry oF CHICAGO. 
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