5 1 6 Farmer. — On Spore-Formation and 
sperms, the linin is discoverable at a very early stage as 
a much coiled thread, in which the chromatin particles are 
distributed. As the coil shortens and thickens, the chromatin 
is seen to be specially located in two lines along the edge of 
the filament, whilst the intervening clearer part of the linin 
marks the tract of the longitudinal fission. The chromosomes, 
thus made up of a linin basis, in which the chromatin is 
imbedded, eventually become isolated by the ‘ thinning-out J 
and final disappearance of the linin at certain transverse areas, 
and in this way the length of each chromosome is determined. 
But in Hepaticae the process is complicated by the existence 
of anastomoses, and the chromosomes are by no means 
delimited in so orderly a fashion as in Lilies. The longi- 
tudinal fission is often recognized only with difficulty, so much 
so that at one time I doubted its occurrence. 
The appearance of the chromatic areas in the Jungermanniae 
is highly characteristic. The young chromosomes usually 
form more or less ring-like structures, the chromatin in which 
is frequently seen to be grouped in a manner which strongly 
suggests that a double distribution of the chromatin for the 
next two divisions occurs here (see Figs. 5, 6, 7, 8, 22, 38). 
There is, so far as I know, no a priori objection which can be 
urged against this. Brauer showed that it happens in Ascaris , 
and Flemming showed that a longitudinal division of the 
daughter-chromosomes of the one mitosis in the spermato- 
cytes of Salamander occurred before going into rest, whereby 
the number of chromosomes for the final mitosis was already 
prepared for. 
Later on, this curious appearance in the rings is lost, and 
the chromosomes contract and bend over on themselves, 
assuming the well-known humped appearance so character- 
istic of the corresponding mitosis in the pollen-mother-cells of 
Phanerogams. An explanation of the highly complex develop- 
ment which these chromosomes pass through before they 
finally divide on the spindle has been attempted elsewhere 1 , 
1 Farmer and Moore, loc. cit. 
