28 
FRED. ELFVING. 
Iris xiphium ; the development is similar to that of I. sih~ 
irica. I once observed one of its vegetative cells^ whose 
nucleus had divided. The nucleus of the big cell sometimes 
goes first into the tubes and sometimes that of the small 
one. They also often go beside one another. The substance 
of the large nucleus becomes very much elongated on enter- 
ing, and approaches the point of the tube by bending and 
twisting itself. The vegetative nucleus retains its shape 
even after the dissolution of its surrounding protoplasm 
(fig. 30). 
Tradescantia virginica ; here the nuclei are very strangely 
formed (fig. 37), as Hartig has already remarked. One of 
them is very long and narrow, curved, with bent-in, almost 
rolled-in, ends ; it is, indeed, often of a trichina form. The 
other is round and finally of the same star-shaped form 
which is met with in Anthericum liliago. Both are devoid 
of nucleoli. The developmental history tells us that the 
former nucleus originates from the larger cell; while the 
other sausage-shaped one is the considerably modified vegeta- 
tive nucleus. I may here mention in passing that the manner 
of division corresponded with that described by Strasburger 
for the integument-cells of Nothoscordum fragrans Ueber 
Befruchtung und Zelltheilung,’ p. 517, Taf. xxxiii, figs. 
47—54). 
I examined the Pollen-tubes, w'hich were prepared out of 
the style. These tubes grow out of one end of the Pollen- 
body. Already, whilst the two nuclei lie in the Pollen-body, 
the round one becomes much elongated, and after the two have 
entered the tube they are in every respect similar, becoming 
very long and drawn out. I discovered, however, some 
instances in which the vegetative nucleus lay in the Pollen- 
body with its characteristically rolled- up ends, while the 
other had already left it. 
Sparganium ramosum shows a similar development to 
that of Typha angustifolia. The formation of starch 
(which hinders observation in Typha) begins, how- 
ever, later, so that I can state positively that the vegeta-. 
tive cell generally separates itself and assumes a spindle 
shape (figs. 41, 42). The vegetative nucleus only becomes 
free after further development (fig. 43), after which its 
nucleolus vanishes (fig. 44). The nucleus becomes deeply 
coloured by carmine. The nucleolus of the large nucleus, 
deeper coloured, can generally be found in the ripe Pollen- 
body. 
The nucleus of the large cell sometimes goes first into the 
Pollen-tubes (5 — 10 per cent., eighteen hours) and sometimes 
