INTRODUCTORY 



The Myxomycetes, or slime-moulds, include certain very delicate 

 and extremely beautiful fungus-like organisms common in all the 

 moist and wooded regions of the earth. Deriving sustenance, as they 

 for the most part do, in connection with the decomposition of organic 

 matter, they are usually to be found upon or near decaying logs, 

 sticks, leaves, and other masses of vegetable detritus, wherever the 

 quantity of such material is sufficient to insure continuous moisture. 

 In fruit, however, as will appear hereafter, slime-moulds may occur 

 on objects of any and every sort. Their minuteness retires them from 

 ordinary ken; but such is the extreme beauty of their microscopic 

 structure, such the exceeding interest of their life-history, that for 

 many years enthusiastic students have found the group one of peculiar 

 fascination, in some respects, at least, the most interesting and re- 

 markable that falls beneath our lens. 



The slime-mould presents in the course of its life-history two very 

 distinct phases: the vegetative j or growing, assimilating phase, and 

 the reproductive. The former is in many cases inconspicuous and 

 therefore unobserved ; the latter generally receives more or less atten- 

 tion at the hands of the collector of fungi. The vegetative phase 

 differs from the corresponding phase of all other plants in that it 

 exhibits extreme simplicity of structure, if structure that may be 

 called which consists of a simple mass of protoplasm destitute of cell- 

 walls, protean in form and amoeboid in its movements. This phase 

 of the slime-mould is described as plasmodial and it is proper to 

 designate the vegetative phase in any species, as the Plasmodium of 

 the species. It was formerly taught that the Plasmodium is uni- 

 cellular, but more recent investigation has shown that the plasmodial 

 protoplasm is not only multinuclear but karyokinetic ; its cells divide 

 and redivide, as do the reproductive cells of plants and animals gen- 

 erally. Nevertheless, in its plasmodial phase, the slime-mould is 

 hardly to be distinguished from any other protoplasmic mass, may be 



nonRTY UBRARY 

 H. C. StaU Collect 



