436 J. SLADE ON MYCETOZOA. 



to form either sporangia enclosing spores, or sporophores bearing 

 spores on the outer surface. 



In many cases quantities of crystals of carbonate of lime, 

 with the colouring-matters, remain behind as the wreckage of the 

 Plasmodium. 



The solid structures, such as the sporangial wall, capillitium or 

 spore case, do not seem to be made of cellulose, but rather of a 

 congealed protoplasm. 



Thus we see that the stages in the life-history of the Myceto- 

 zoan, which distinguish it from all other organisms, are : (1st) firm- 

 walled spores, giving rise to (2nd) swarm spores, which coalesce 

 and form (3rd) a plasmodium. 



The life-history of a Mycetozoan is divided into a nutritive 

 stage, consisting of naked, membraneless, protoplasmic masses, 

 and a reproductive, spore-producing stage. In the nutritive 

 stage they very nearly resemble some groups of the Protozoa — 

 e.g., the flagellate infusoria. In the manner of their reproduction 

 they certainly show affinities to many Fungi. But in the Fungi 

 the germinating spore never produces a plasmodium, but only a 

 mycelium. 



There is no evidence in favour of the supposition that the 

 Mycetozoa are degenerate members of the vegetable kingdom ; 

 whereas the idea that the Fungi originatediby differentiation from 

 chlorophyll -bearing plant ancestors is generally admitted. 



We have in the Mycetozoa a very remarkable group of 

 organisms, in more ways than one. Not only are they beautiful 

 objects in themselves, but they stand on the common ground or 

 borderland, if such there be, between the animal and vegetable 

 kingdoms. 



These facts alone should increase our interest in this group of 

 animated nature. But there is yet another aspect in which we 

 may view it, perhaps beyond the bounds of proof, but yet within 

 the range of the imagination. Professor R. Lankester says, 

 " There is some reason to look upon the Mycetozoa as the nearest 

 representative of that first protoplasm which was the result of 

 long, gradual evolution of chemical structure, and the starting- 

 point of the development of organic form." 



It is quite true that our present knowledge of existing organ- 

 isms is all on the side of Harvey's maxim, " Omne vimm ex vivo.*' 

 But if, to quote Professor Huxley, " if it were given to us to look 



