32 TJie Mycetozoa, and 



To the receptive ova of Cutleria adspersa, Falkenburg 

 added actively mobile spermatozoids of the nearly allied 

 species Cutleria multifida ; so like the other species adspersa 

 that they can only be distinguished by small external 

 differences. " In this case the spermatozoids, as seen by 

 the microscope, wandered aimlessly about, and finally died 

 without having fertilized the ova of the allied species of 

 algas. ... A very different result was obtained as soon 

 as a single fertilizable ovum of the same species was intro- 

 duced into the vessel containing the spermatozoids. After 

 a few moments, all the spermatozoids from all sides 

 gathered around this ovum, even when the latter was 

 several centimetres distant from the place at which the 

 latter were chiefly collected." 



These instances impress the mind with the fundamental 

 character of the fact of species ; whether it has arisen from 

 variation and selection or not, it is a fact that goes down 

 to the very foundations and rudiments of organic life, and 

 even there influences the life and habits of the organism. 

 As we see it in the myxies, it precedes the origination of 

 the sexual distinction, it precedes any differentiation of 

 parts or organs, it precedes the development of the cellular 

 tissue. It may, perhaps, be said to precede the division 

 into the animal and vegetable kingdoms. The distinction 

 can exist in small naked bits of protoplasm, and each of 

 these, indistinguishable in structure as the protoplasts of 

 some of the species are to any organs or instruments which 

 we possess, has the power of distinguishing between these 

 indistinguishable masses, of attracting and being attracted 



