39 
in the Root- Apex of Phaseolus . 
nucleolus. The mantle-fibres of the spindle condense during the anaphase 
into a granular mass, which becomes the nucleolus and passes into the 
daughter-nucleus. The extranuclear nucleoli which are sometimes seen 
at the anaphase along the new cell-wall also originate from the connecting 
fibres. 
Nemec, however, in a later paper 1 , points out that, although his obser- 
vations indicate the connexion between nucleoli and spindle-fibres, other 
explanations of the phenomena are possible, and remarks that these obser- 
vations only prove certainly that there is some definite relation between the 
nucleolus and the division process, and that there is a definite connexion 
between the size of the nucleolus and the power of the nucleus to divide ; 
in this he agrees with Schwarz 2 . The solution of the nucleolus and 
the formation of the spindle-figure might be two quite different processes, 
having this only in common that they go on side by side. 
Chamberlain 3 finds a distinct connexion between nucleoli and chro- 
matin in the oosphere-nucleus of Pinus Laricio. The chromatin takes the 
form of nucleoli, which collect from all parts of the nucleus to a definite 
area near the centre, and there develop into a typical spireme. 
Duggar, in his studies on the pollen-grain and embryo-sac in Symplo- 
carpus , Peltandra, and Bignonia 4 , has some very interesting observations on 
the relation of the nucleoli and the chromatin-elements. The nucleolus 
takes the chromatin-stain mainly, the nuclear reticulum very little. 
During the formation of the chromosomes they remain attached to the 
nucleolus by minute linin-threads, and the nucleolus is often drawn out 
by these into a fusiform shape. In Bignonia , ‘ in the dispirem of the 
daughter-nuclei the chromosomes become very irregular in outline, and 
gradually diminish in size, while there is gradually formed a large nucleolar- 
like body with irregular outlines. This body takes the chromatic dyes as 
did the nucleolus generally before/ Speaking of the second division, the 
author says : ‘ Everything indicates that the nucleolus of the microspore- 
nucleus has thus resulted from the direct or indirect fusion of chromatic 
material used in division/ 
Mottier 5 concludes that in Dictyota c the behaviour of the nucleolus, 
during both the development of the nuclear figure and the construction of 
the daughter-nuclei, indicates that this body represents a substance which is 
utilized by the chromatin and not by the spindle-fibres/ 
1 Neue cytologische Untersuchungen : Sonderabdruck aus Fimfstiick’s Beitragen zur wissenschaftl. 
Bot, iv, 1900. 
2 Die morphologische und chemische Znsammensetzung des pflanzlichen Protoplasmas. Cohn’s 
Beitr. z. Biol. d. Pflanzen, v. 
3 Oogenesis in Pinus Laricio , Bot. Gaz., xxvii, 1899. 
4 On the Development of the Pollen-grain and the Embryo-sac in Bignonia mnusta, Bull 
Torrey Bot. Club, xxvi, 1899. Studies in the Development of the Pollen-grain in Symplocarpu 
foetidus and Pdtandra undulata , Bot. Gaz., xxix, 1900. 
5 Nuclear and Cell Division in Dictyota dichotoma , Ann. Bot., xiv, 1900. 
