APPENDIX TO VOL. I. 



THE MYXOMYCETES OR MYCETOZOA. 



AT pages 41 to 43 and 193 of this volume (published in Parts I. and II., October 

 and November, 1880), the Myxomycetes or Mycetozoa have been somewhat exten- 

 sively referred to as exhibiting, in accordance with the researches of De Bary and 

 Cienkowski, so close an affinity with the typical Flagellate Infusoria that they cannot 

 be consistently retained in their old place among the Gasteromycetous Fungi, but 

 must be advanced to a position among the Protozoa at no very remote distance from 

 the group Spongida. In the pages of ' Grevillea,' for December 1880, the editor, 

 Dr. M. C. Cooke, has, as a mycologist, lodged a somewhat strong protest against the 

 proposed transfer, arguing that more substantial evidence than a mere citation of 

 these continental authorities is required to prove the animal nature of these 

 organisms. In the 'Popular Science Review' for April 1881,* the author has, in a 

 re'sumd of the structural and developmental features of the Myxomycetes, fully 

 replied upon all the points raised by Dr. Cooke, and added to the evidence pre- 

 viously adduced the record of a recent personal investigation of the developmental 

 phenomena of several Myxomycetan types, including more especially the Physarum 

 tussilaginis of Berkeley and Broom,f originally discovered in this country by 

 Mr. Thomas Brittain of Moss-side, Manchester, and to whom the author is indebted 

 for the receipt of authenticated specimens. The results obtained through the 

 careful cultivation of the spores of this species have so fully confirmed and added 

 to the testimony first submitted by De Bary and Cienkowski, that the author is 

 prepared, even more confidently than hitherto, to support the animal interpretation 

 of their nature and affinities. A brief abstract of the developmental data recorded 

 by the author in connection with this species is herewith reproduced. 



The spores in question primarily enclosed in a depressed sessile sporangium 

 having a delicate membranous wall studded with minute stellate spiculae % were 

 sown in distilled water on ordinary slides, covered with thin glass, and kept when not 

 under direct examination in a moist chamber. So soon as within seven hours after 

 wetting them, or indeed directly following their deposition on the slide, an examin- 

 ation revealed the companionship of innumerable quiescent Bacteria, with a more or 

 less abundant sprinkling of spores other than those of Physarum, and of consider- 

 ably smaller size. The spores specially sown, having a diameter of 1-2000" to 

 1-1500", were found, under high magnification, to consist of an outer wall of con- 

 siderable thickness, finely echinulate externally, and exhibiting, by transmitted light, 

 a dark amber or chitinous coloration. The protoplasmic contents rarely entirely 

 filled the outer shell, but remained separated from it by a greater or less number of 

 angular interstices. A central spheroidal nucleus, with a contained nucleolus, one 

 or more large refringent corpuscles, and numerous smaller granules, represented the 

 sum-total of the recognizable internal elements. By the end of the second day 

 active life had already dawned upon the scene. Bacteria were swiftly propelling 

 themselves to and fro in all directions ; one or two biflagellate monads, Heteromitce, 

 whose development was subsequently traced from certain of the smaller spores above 

 mentioned, glided slowly along, dragging their posterior flagella, " gubernacula," 

 cablewise behind them. Sparsely scattered amongst the spores of the Myxomy- 



* "The Myxomycetes or Mycetozoa; Animals or Plants?" by W. Saville Kent, F.L.S., &c., 

 ' Pop. Sci. Rev.,' New Series, vol. v. No. xvii. pi. iii. and iv., 1881. 



t 'Ann. Nat. Hist.,' p. 139, Feb. 1856. J ' Pop. Sci. Rev.,' pi. iv. figs. 30-35. 



