THE MYXOMYCETES 289 



a number of distinct protoplasmic bodies. As there is 

 no fusion of nuclei, the process cannot be regarded as of 

 a sexual nature. 



When a plasmodium has been started in this way it 

 continues to grow, and the number of its nuclei increases 

 by division to keep pace with its growth, a fact which 

 is now well ascertained. 



Such are the outlines of the life-history of these 

 extraordinary creatures, which in their whole structure 

 and mode of development differ widely from any other 

 organisms. We can study in them, better perhaps than 

 in anything else, the behaviour of living protoplasm when 

 untrammelled by the bonds of cellular structure. We see 

 how closely movement and growth are connected ; and 

 when the period of fructification comes on, we can observe 

 how the protoplasm by its active exertions literally builds 

 up the new structure out of its own substance. It has 

 been well said that in the plasmodium of a Myxomycete 

 we have a type of the organisation of all plants, for we 

 see in these organisms, freely exposed to view, the same 

 movements and the same constructive activity of the 

 living matter, on which the growth and development of 

 the highest plants depend. In the latter, however, the 

 living agent is concealed within the framework of the 

 eells, and its successive changes of form are stereotyped 

 by the rigidity of the structures which it has itself 

 built up. 



