Fertilization in Lilium. 
BY 
V. H. BLACKMAN, Sc.D, F.L.S., 
AND 
E. J. WELSFORD, F.L.S. 
With Plate XII. 
.THOUGH the process of fertilization in the higher plants has 
ii received much attention we are still surprisingly ignorant of many 
of its important physiological and anatomical details. The behaviour and 
function of the synergids, the nature of the mechanism by which the two 
male nuclei reach their respective goals, the exact relation of the pollen-tube 
to the embryo-sac and the manner of the tube’s opening, the stage at which 
vermiform nuclei first take on their peculiar shape, are all problems which 
require further investigation. What important results are to be obtained 
by a careful study of a few forms is shown by Nawaschin’s 1 investigation of 
Fritillaria tenella , Juglans nigra , and Helianthus annuus. He shows how 
different are the details of fertilization in these three forms, and brings 
forward very convincing evidence for the view that, in these cases at least, 
the male nuclei are motile, making their way through the embryo-sac 
by their own activity. 
The observations here briefly described are the result of the investiga- 
tion of some material originally intended for class-work. Portions of 
ovaries of Lilium Martagon were fixed in the summer of 1907 and put on 
one side. When examined later it was found that the fixation was 
extremely good, and that some of the material had been caught at a very 
fortunate stage. The quality of the material is shown by the fact that on 
one slide no less than twenty-two triple fusions were to be observed, and in 
many of the same ovules the fusion of the male and female nuclei could 
also be seen. 
1 Ueber das selbstandige Bewegungsvermogen der Spermakerne bei einigen Angiospermen. 
Osterreich. botan. Zeitschr., lix, 1909, p. 457. 
[Annals of Botany, Vol. XXVII. No. CV. January, 1913.] 
