On Pallavicinia decipiens , Mitten. 47 
shanks, which thus appear as dots, and of course twice as 
many as the actual number of the loops. 
This relation between the nuclei of the sporophyte and 
the gametophyte respectively, affords strong confirmation to 
Overton's 1 view of the meaning of the halving of the numbers 
of the chromosomes in the reproductive cells of Phanerogams, 
when contrasted with the corresponding vegetative nuclei. 
As the development of the sporogonium proceeds, the wall 
becomes several layers of cells in thickness, and the contents 
of the capsule differentiate into elaters and spore-mother-cells. 
The former are characterized by their increasingly elongated 
form, whereas the spore-mother-cells finally become rounded 
bodies. The elaters are scattered through the sporogenous 
tissue, and do not form strands, such as occur in Aneura or in 
Pellia. 
Development of the spores . — The spore-mother-cells are 
somewhat poor in their cytoplasm, which contains large 
quantities of oil. A nucleus of large size, enclosed in a 
special protoplasmic mass, occupies a central position in the 
cell. Presently the characteristic change which precedes the 
actual formation of spores in the Hepaticae becomes apparent. 
The mother-cell becomes tetrahedrally lobed, and the cell- 
walls, at their inner angles, grow into the cell-cavity towards 
the nucleus. 
This body is surrounded, as has been said, by somewhat 
dense protoplasm which probably represents an archoplasm, 
and just before nuclear division it behaves in a most striking 
manner. Simultaneously it projects out into each lobe of the 
mother-cell, and thus forms a four-rayed star, with the 
nucleus occupying the centre. These arms, or spindles together 
form what I have recently, in a paper communicated to the 
Royal Society 2 , termed a ‘ quadripolar spindle.’ The spindle- 
arms or rays stain deeply with nuclear stains, and I am 
strongly of opinion that the substance from the nucleolus 
1 E. Overton, On the reduction of the Chromosomes in the Nuclei of Plants, 
Annals of Botany, vol. VII. 
2 Proc. Roy. Soc., vol. LIV, No. 330, 1894. 
