1 8 The Mycetozoa, and 



An organism which commences life in the simple form 

 of a piece of protoplasm, in many cases produces cell walls 

 and rests in these, and thus builds a home for itself in 

 which it lives and labours. But in the case of the 

 Myxomycetes this does not occur, or occurs only very 

 exceptionally, and all the actions which these organisms 

 perform, and all the beautiful forms which they assume, 

 are reached without ever forming a cell wall or constituting 

 a true cell, except in the spore itself. In these actions and 

 in these forms we see the capacities of simple and naked 

 protoplasm. The extreme simplicity of the mechanism 

 seems to bring to the mind more powerfully the inherent 

 powers of the worker. 



NUCLEI. In the history of the theory of cells it was early 

 discovered that there is in each cell a smaller structure called 

 the nucleus, which was originally supposed to be a vesicle 

 in the cell, but has been now ascertained to be a portion of 

 a special substance distinct from protoplasm. The nucleus 

 has been found to exercise something like a dominant 

 influence on the destiny of the cell " all the formative 

 and nutritive processes seem to be dependent upon it," 

 and, moreover, it plays an important part in each process 

 of cell division i.e., in some or all cases of the division 

 of the cell the nucleus undergoes a like division. This 

 division occurs in three ways, of which two only need 

 now be noticed. One of these modes of division is very 

 simple. The nucleus gets constricted in the middle, the 

 connecting link grows slighter and slighter, and breaks, 

 and we have two nuclei where before we had one. 



