268 Welsford . — The Genesis of the Male N tic lei in Lilium. 
The male nuclei thus, either with or without their cells, are seen to 
travel from io to 16 mm. in five days in Lilmm Martagon , or from 
12 to 20 mm. in about seven days in Lilium auratum, before they effect 
fertilization. It is also a noticeable fact that, after the male cells are formed, 
the protoplasm of the tube no longer has an appearance of active streaming, 
but instead sometimes looks as if it had been disturbed by a moving body 
(Figs. 24, 25). The nuclei during their passage down the tube alter slightly ; 
they never pass into the typical reticulate resting stage, but form a spireme 
with very few and very delicate cross-connexions (Figs. 24, 25); these 
connexions become more pronounced in the mature sperm nuclei, and 
especially so in those nuclei in the later stages of fusion, such as are shown 
in Figs. 1 and 6 in the previous paper. It seems, therefore, that the sperm 
nuclei in Lilium auratum and Lilium Martagon have undoubted motility 
for a considerable period, and it is suggested that this may be correlated 
with the fact that there is a minimum of cross-connexions between the 
chromatin threads during a great part of their existence. The cytoplasm 
of the male cells soon disintegrates after the loss of the nuclei, and doubtless 
gives rise to the structures termed ‘ X-Korper ’ by Nawaschin. 1 
The material was fixed in Flemming’s fluid of various strengths and in 
Perenyi’s fluid, and was stained with Benda’s iron-haematoxylin or with 
BreinPs stain. 
Summary. 
1. The vermiform nuclei of Lilium auratum and Lilmm Martagon pass 
down the pollen tube in male cells and are usually only liberated from 
their cytoplasm after the pollen tube has entered the embryo sac. 
2. The male nuclei are regarded as possessing motility from an early 
stage of their development. 
3. The ‘X-Korper’ of Nawaschin are shown to be the disintegrating 
cytoplasm of the male cell 
4. The history of the bands of granules sometimes found near the 
disintegrating cytoplasm suggests the possibility that they may be vestiges 
of blepharoplasts. 
EXPLANATION OF PLATES XVI AND XVII. 
Illustrating Miss Welsford’s paper on the male nuclei of Lilium. 
PLATE XVI. 
Fig. 1. Lilium auratum. Single nucleus of pollen-grain preparing for division, x 1,200. 
Fig. 2. Lilium auratum. Later stage of same, x 1,200. 
Fig. 3. Lilium auratum. Ditto, showing the twenty-four daughter chromosomes separating 
from each other, x 1,200. 
1 Nawaschin, S. : Naheres fiber die Bildung der Spermakerne bei Lilium Martagon. Annales 
du Jard. Botan. de Buitenzorg, 2 e ser., Suppl. iii, 1910. 
