Nuclear Division in the Hepaticae. 473 
more recent results obtained from microchemical examination 
of the cell, so far as they afford any evidence at all, are against 
it. But it may very well be that some constituents of 
chromatin find their way ultimately into this body, since both 
chromatin and the nucleolus readily yield albumen on appro- 
priate treatment 1 . 
The Development of the Spores of Fossombronia 
Dumortieri. 
After the last archesporial divisions have been completed, 
the spore-mother-cells loosen their union with each other, and 
grow for a time before undergoing any further change. The 
nuclei are at first rather small, and contain a very prominent 
nucleolus. The linin constituent is very poor in staining 
substances, and is rather difficult to trace. As the cells 
approach their full size they become somewhat four-lobed, 
each protuberance corresponding to a future spore. But the 
lobed appearance is not nearly so striking here as in most 
other genera of the Jungermannia-series of Hepaticae. When 
the cell reaches its full size the nucleus alters in structure. 
The linin becomes very clear as a delicate threadwork within 
the nucleus. It seems always to pass through a peculiar 
phase about this time, being much massed up together, and 
this aggregation occurs almost always in the vicinity of the 
nucleolus. Afterwards it again is visible as an anastomosing 
mass of threads, which are somewhat tightly stretched from 
one knot or anastomosis to another. The whole thread now 
thickens somewhat, and there are seen other threads of very 
delicate texture running from the nucleolus to the thicker 
linin. Whether these thinner filaments are remains of the 
original linin which have not shared in the general increase in 
bulk it is not possible to say ; they are at least similar to it 
in staining characters. But however this may be, they served 
to connect up the linin with the nucleolus at this stage. I am 
1 Kossel, Ueber die Nucleinsaure, Verhandl. d. Physiol. Gesellsch. z. Berlin, 
1892. Zacharias,f t Ueber d. Chemische Beschaffenh. v. Cytoplasma u. Zellkern, 
Ber. d. deutsch. Bot. Gesellsch. 1893. 
