Phobo-chemotaxis of the Swarm-spores 

 of Myxomycetes. 13 



By 

 S. Kusano. 



The chemotactic movement of the swarm-spores of Myxo- 

 mycetes was first observed by Stange in 1890. 2 ) He found 

 that the swarm-spores of Chondrioderma diftorme and Aethalium 

 septicum are attracted by some organic acids, such as malic, 

 butylic, valerianic and propionic acids, and some of their 

 neutral salts of alkali metals, but never by inorganic and other 

 organic acids, such as phosphoric, tartaric and citric acids. 

 Moreover, he came to the conclusion that the attractive 

 substance is, more or less, specialized to each species. For 

 instance, Chondrioderma is especially attracted by malic acid 

 and asparagin while Aethalium on the other hand is attracted 

 more strongly by lactic, butylic and valerianic than by malic 

 acid. Basing on the modern theory of electric dissociation 

 it may be remarked that Stange's investigation is not yet 

 conclusive as for the active component of solutions tested by 

 him. Consequently, in the present study much attention has 

 been thrown upon this point, while intending to extend our 

 knowledge on the chemotaxis of the other Myxomycetes. 



For the material of this experiment I have collected nearly 

 twenty species of Myxomycetes at the Botanic Gardens, Koishi- 

 kawa. From all fresh collections, however, only three species, 

 namely Aethalium septicum, Stemonitis rnsca and Comatricha 

 longa, have produced swarm-spores most easily in distilled or 

 tap-water. Especially Aethalium, supplying the most active 



x) A preliminary report read before the Tokyo Botanical Society. May, 1907. 

 A short account has already appeared in Japanese in Bot. Magaz. XX. 1906. p. 23. 

 2 ) Stange, Bot, Ztg. XLVIII. 1890. p. 107. 



