PELOMYXA CAROLINENSIS (WILSON) OR CHAOS CHAOS (LINNAEUS)? 1 NOLAN E. RICE Ciirclinn Biological Supply Company, Ehm College, \<>rtli (\in>Hna INTRODUCTION Considera1)le confusion exists concerning the name of the large amoeboid or-ganism which was discovered and named Pclouiy.va carolinensis by Wilson in 1900. The other name by which this organism is known is Chaos cliaos (Lin-naeus). It is the purpose of this paper to show that the valid scientific name i> Peloiiiv.ni caTolinensis \\'ilson. HISTORICAL The historical data have been presented in full elsewhere (Schaeffer, 1926; Mast and Johnson, 1931 ) but for clarity of discussion it is necessary to list the pertinent facts. 1. In 1755 Roesel von Rosenhof found an amoeboid organism which he de-scribed, figured, and named "der kleine Proteus." 2. In 1758 Linnaeus named Roesel's organism 1'olvo.v chaos and in 1767 Chaos chaos because the name Volvox had been used earlier for the colonial flagellate which today bears that name. 3. In 1900 Wilson discovered a large amoeboid rhizopod in North Carolina which he described and named Pcloiny.va carolinensis. 4. This organism was again found by Penard in France (1902) ; Kepner and Edwards, in Virginia (1917); Schaeffer, in Tennessee and Xew Jersey (1937); and Brandwein, Penn, and Shiel, in New York (1943). It is now being main-tained in clone cultures by Schaeffer, Belda, Pace,-Rice, and perhaps others. 5. Schaeffer (1926) maintains that Roesel's "der kleine Proteus" and Wil-son's Pelowiyxa carolinensis are identical genetically and specifically, and that the valid scientific name is therefore Chaos chaos (Linnaeus). Stiles (1905), how-ever, believes that the name Chaos chaos ( Linnaeus) is the valid name for Amoeba protcus Leidy, maintaining that Roesel's "kleine Proteus" is like tin's common lab-oratory amoeba. j 6. Mast and Johnson (1931) present evidence which shows that Roi>iT ganism "is neither generically nor specifically like either Leidy's proteus nr \\il-son's carolinensis." They contend that it is a myxomycete, "an organism usually classified as a plant." 1 The author desires to express his grateful appreciation to Dr. T. E. I'o\vel1, Dr. I . \\ . Hagquist, and Mr. T. H. Mackintosh of the Carolina Biological Supply Company for many helpful criticisms in the preparation of this paper. 2 Dr. D. M. Pace, College of Pharmacy, University of Nebraska, kindly furnished tin pelomyxae from which the author's clone was established. 139
BioStor
