Mar. 1901.] BOTANICAL SOCIETY OF EDINBURGH 69 



In virtue of their reciprocal attraction the biomores will 

 now be oriented, according to their structure, and conse- 

 quently according to Fig. 1, As each biomolecule, however, 

 is double, their orientation also will be doubled, and will 

 bring about the division of the biomore into two biomores 

 similar to A, thus — 



a a 



(4) / * / * 



^ e c c c 



d d 



The division of the biomonad and cell takes place 

 similarly. "When assimilation has doubled the number of 

 biomolecules the biomores will divide ; the system of 

 biomores will then be doubled, and the orientation of the 

 biomores (which is possible because they possess a certain 

 mobility being plunged in a fluid, and because they have 

 a reciprocal attraction in virtue of their chemical constitu- 

 tion) which follows, will induce the division of the bio- 

 monad into two new biomonads. 



In a series of twenty-one ingenious diagrams v/e see 

 this gradual orientation of the biomores in biomonad and 

 cell during the successive stages of division leading to the 

 production of the well-known figure of karyokinesis. Cell 

 division is a mechanical phenomenon based on the chemical 

 attraction of the biomores. 



Other interesting conclusions in this chapter are, that 

 the centrosphere, and the aster, etc., are ephemeral 

 morphological formations, but materially persistent, i.e. the 

 biomores which constitute them always persist as such, 

 although they lose their characteristic arrangement which 

 gives the aster, etc., during the processes of assimilation. 

 The formation of the centrosphere, the asters, the spindle, 

 the nuclear plate, the separation of the chromosomes, and 

 the separation of the two daughter cells, are all phenomena 

 depending on the same cause — orientation of the biomores. 



Interesting also are the remarks on the so-called 

 " resting stage of the cell," which ought, according to the 

 author, to be called the " assimilatory period," inasmuch as 

 during this phase the cell is the seat of continual chemical 

 and mechanical work. 



In chapter vii. are stated 28 laws of cell division, 



