THK :\IYX()^rY('KTES. 95 



AFFIXITIKS OF TIIK MYXOMYCETES. 



Wo are now prepared to consider what the affinities of the Myxo- 

 mycetes ui-e, and it becomes at once apparent that the question, so far 

 from beiutj capable of settlement off-hand, as some would treat it, is 

 really very complex ; for the analo<,'ies which we can perceive between 

 these organisms and other members of the animal and vegetable 

 world ai'e very numerous and far-reaching. It becomes a question, 

 then, which analogies indicate affinit^y, and which are merely those 

 apparently accidental i-esemblances which occur throughout everj" 

 department of Nature. 



The sporangia bear a considerable likeness to those of some Gas- 

 tromycetous Fungi, especially in the fact that the interior, when 

 mature, is tilled with a dusty mass of threads and spores, but as aJi'eady 

 mentioned the origin of the spores is quite different in the two cases. 

 The sporangia resemble also more remotely the capsules of Mosses 

 and Hepaticas, while the spiral threads which are mixed with the 

 spores of Trichia remind us of the elaters of the Jungermanniese ; but 

 from these they differ in the fact that the elaters are cells, with a 

 separable spiral coiled within, while the Ti'ichia threads, even if it be 

 granted that they are cells, contain no spiral, the appearance being an 

 optical efl'ect produced merely by a rounded spirally-arranged eleva- 

 tion of the outer wall.* The spores also outwardly are like the spores 

 of many other Fungi, but the development of the spore is sui fieiieria, 

 and its contents, as soon as they have developed their flagellum, 

 resemble common free-swimming monads, and in their creeping stage, 

 first, the infusorian Mastigamceba, and, secondly, the rhizopod Amoeba. 

 Again, we can compare the huge plasniodium formed by their union 

 with the ramifications of the protruded protoplasm of the Foramini- 

 fera, in which also the same cyclosis or slow circulation of the contents 

 is observed. It may also be compared, according to Saville Kent, to 

 the homogeneous sarcode which forms the basis of sponge structure, 

 which in the same way is composed, if our authority be correct, by 

 the amalgamation of a vast number of amcsbiform vmits. Moreover, 

 the substance of the threads which occur with the spores, according 

 to the same author, bears some likeness to that of the keratose or 

 homy fibres of the order of Sponges called Cer«^/;(a, while still more 

 strangely the calcareous deposits in many species simulate those of 

 the order of Sponges called Calcaren, and in a few, he says, even 

 assume a regular six-rayed form, reminding one irresistibly of a sponge 

 spicule. But in these respects the author's enthusiasm seem to have 

 outrun his judgment ; the threads of the Myxomycetes are not of a 

 very homy natui'e, nor are the crystals by any means so regular as he 

 would imply. 



But, even allowing these resemblances, and that the Sponges 

 belong to the Protozoa, can we find anything in the Protozoa at all 



* " Quarterly Journal of Microscopical Science," 1855, pp. 15-21. But the 

 opposite opinion has been maintained ; " Transactions of the Linnaean Society," 

 XXI., i^p. 221-3, where, however, the figure contradicts the text. 



