CH. VIII. — MORPHOLOGY AND COURSE OF DEVELOPMENT. — AFFINITIES. 445 



shows the amoeboid movement of a plasmodium, it has not the character which is 

 involved in the origin of a plasmodium ; this is the case too with the spore of 

 Porphyra which also has the power of amoeboid motion. 



There is therefore no real ground for assuming a direct relationship with these 

 Chytridieae, whether they do or do not form a natural group with the other species 

 which produce mycelia, a question which, as was explained in Chap. V, must for the 

 present remain undetermined. 



It is a totally different question whether it is possible to suppose a common 

 origin for these particular Chytridieae and the Mycetozoa, and consequently a more 

 remote and indirect relationship. The comparison of the facts known to us shows it 

 to be probable, as Biitschli points out, that the starting point of the naked Amoebae 

 of the zoologists is to be sought in the group of very simple organisms known as the 

 Flagellatae, and a study of the swarm-spores of the Mycetozoa leads to the same 

 view, for in the stage of their existence when they are furnished with cilia they have 

 all the characters of the simpler Flagellatae. But not only the Chytridieae which 

 produce no mycelium but all the group show such close affinity to the Flagellatae, 

 that they might if necessary be phylogenetically derived from them. But this is true 

 also of the entire assemblage of the simple Algae, with which it was sought to connect 

 the Fungi in the sections of Chapter V. We may as well place the Volvocineae 

 with the Flagellatae as with the Chlorophyceae, if we prefer that arrangement, and 

 no one will doubt the close affinity which exists between them and the rest of the 

 undoubted Chlorophyceae. 



If then we distinctly separate the Mycetozoa from the Fungi, and are prepared 

 even to draw the boundary line which divides the two organic kingdoms between these 

 groups, we do not thereby deny that members of the two divisions may approach very 

 near to the group of the Flagellatae, towards which all the evidence shows that the 

 two kingdoms converge, and thereby approach also very near to one another. 



The purpose of the foregoing remarks has been to do for the Mycetozoa what 

 was previously done for the Fungi, namely to establish their affinities on the foundation 

 of the facts of which we are at present in possession, or speaking more boldly to give 

 the true account of them. Such an attempt whenever made must be made with the 

 material then at hand. If the foundation of facts changes with the progress of our 

 researches a fresh attempt must be made. 



The views of botanists as to the position of the Mycetozoa in the system, have 

 already varied much in the course of time. The older view just noticed above, which 

 placed the Myxomycetes with the Gastromycetes on the strength of a mere resem- 

 blance between the mature sporangia in the two groups, has now only a historical 

 interest. Further remarks on this point will be found in my monograph of 1864. 



The ideas with regard to the place of the Mycetozoa in the natural system which 

 were expressed by Famintzin and Woronin in their beautiful work on Ceratium do not 

 at the present day call for discussion. Corau in 1872 endeavoured to connect them 

 with the Chytridieae, chiefly by assuming the formation of plasmodia in the genera of 

 Chytridieae which do not produce a mycelium; but we have already shown that this 

 assumption is without foundation. The opinion represented in Brefeld's work on 

 Dictyostelium (page 20), that this organism might connect the group of the Myxomycetes 

 with the Fungi through the Mucorini, is refuted by a comparison of the course of 

 development in the two groups. The more recent utterances of the same writer on the 



