Meiotic Nuclear Divisions of Galtonia candicans . 747 
one another, at right angles to the plane of the heterotype division (Figs. 79 
and 80). As the chromosomes separate they again contract (Fig. 80), but 
become elongated as they near the poles (Fig. 81). 
Diaster. 
The chromosomes of the four daughter nuclei often arrive simul¬ 
taneously at the poles (Fig. 81), but sometimes one nucleus may be in the 
diaster stage, whilst the other is still in the metaphase. 
Telophase and Anaphase. 
The telophase resembles that already described in the somatic and 
first meiotic divisions. There is the same alveolization of the chromosomes, 
followed by a breaking up of the longitudinal halves into more or less 
beaded portions which are distributed throughout the nuclear cavity and 
are connected with one another by fine strands (Fig. 82). Each nucleus of 
the tetrad gradually rounds itself off and becomes independent of the 
others. The anaphase passes into the ‘ resting ’ stage (Fig. 83). 
‘ Resting ’ Nucleus and Pollen Grain. 
The cytoplasm round the ‘ resting * nucleus becomes vacuolated. The 
linin contents may be in the form of granules showing often a double 
linear arrangement (Fig. 83), or they may be in larger lumps exhibiting 
definite traces of parallelism representing the remains of the alveolized 
portions of the chromosomes of the telophase. 
Thus the ‘resting’ nucleus of the tetrad upholds the principle of 
irregularity so strikingly characteristic of all the divisions of Galtonia. The 
chromatin is here scattered throughout the nucleus, and thus is exactly 
opposed in arrangement to that described by Overton ( 24 ) (1909) in 
Thalictrum purpurascens, and by Rosenberg ( 26 ) (1909) in Crepis virens , 
where the chromatin in the resting pollen-grain nucleus is definitely aggre¬ 
gated into prochromosomes corresponding to the reduced number. 
Then each nucleus with its cytoplasm passes through those changes 
relative to pollen-grain formation. 
General Considerations. 
One of the controversial questions which the study of Galtonia reopens 
is the significance of the parallel threads and linin masses in the hetero- 
type prophases. In Galtonia it is believed that the parallelisms in the 
somatic, premeiotic, and meiotic nuclear prophases are all homologous, and 
in each case that they represent the approximation and concentration of the 
two longitudinal halves of portions of somatic chromosomes. This con¬ 
forms to Strasburger’s ( 30 ) (1904) theory as to the origin of the somatic 
