34 Wager . — The Nucleolus and Nuclear Division 
substance, but as products of excretion resulting from the metabolic change 
taking place between the cytoplasm and nucleus, and especially a secretion 
of the chromatin, which is thrown out of the nucleus during division. 
Farmer 1 states that in the Liverworts he examined 'the nucleolus was 
associated with the chromosomes in an unmistakable and remarkable 
manner.’ Threads of delicate texture run from the nucleolus to the linin. 
These are especially well seen in Fegatella. In a considerable number of 
cases the decrease of nucleolar substance is contemporaneous with the 
growth of the chromosomes. In Fossombronia , for example, 4 the nucleolus 
becomes angular, and, in extreme cases, almost star-shaped, whilst at the 
same time the linin begins to exhibit a very striking increase in the amount 
of chromatin which it contains.’ In a later stage the very much distorted 
nucleolus is often connected with several of the chromosomes, and soon 
after disappears. In the daughter-nuclei the nucleoli appear early, first 
as two or three small bodies which finally fuse to one large one, and the 
linin concomitantly loses its chromatin constituent. This does not 
necessarily imply that the chromatin passes, as such, into the nucleolus. 
But some constituents of the chromatin may find their way into this body, 
since both chromatin and the nucleolus readily yield albumen on appro- 
priate treatment. 
Miss Ethel Sargant’s observations on the formation of the sexual 
nuclei in Lilium Martagon 2 support the view that the nucleoli are con- 
cerned in chromosome-formation. The linin-thread during its growth 
appears to be fed from the partially dissolved nucleolus. Drops of nucleolar 
matter are found attached to the linin-thread in certain stages of its 
development. During the later stages of chromosome-formation the seg- 
ments of the thread become shorter and thicker, and ultimately ‘ the 
colouring (staining) of the chromosome segments becomes uniform. Each 
is apparently homogeneous. There is no contrast between cyanophilous 
granules and erythrophilous ribbon, but the whole chromosome stains 
uniformly like chromatin.’ 
Miss Sargant has very kindly allowed me to examine her preparations 
of the embryo-sac nuclei, and I find that, as she and Professor Farmer 3 point 
out, there is a definite relation between the linin and the nucleoli. Both in 
the resting stage and in the synapsis the nucleolus is connected to the linin- 
network by delicate threads, and in the later stages the chromosomes in 
process of formation are also often connected to it by threads. 
Carnoy and Lebrun 4 describe a series of complicated changes in the 
nucleus of the egg of the Batrachia from which it appears that the 
1 On Spore-Formation and Nuclear Division in the Hepaticae, Ann. Bot., ix, 1895, p. 469. 
2 The Formation of the Sexual Nuclei in Lilium Martagon , Ann. Bot., x, 1896 and xi, 1897. 
3 Loc. cit. (Hepaticae), p. 491. 
4 La cytodi^rese de 1 ’oeuf. La vesicule germinative et les globules polaires chez les Batraciens. 
La Cellule, xii, 1897, and xiv, 1898. 
