ON PELOMYXA VIEIDIS. 357 



On Pelomyxa viridis, sp. n., and on the Vesi- 

 cular Nature of Protoplasm. 



By 



Alfred Glbbs Bourne, ]>.Sc.(l.on<l.), C.M.Z.S., F.Ii.S., 



Fellow of University College, London ; Fellow of Madras University ; 



Professor of Biology in the Presidency College, Madras. 



With Plate XXVIII. 



My assistant, M.R.Ry. A. Sambasivan, B.A. (Madras), 

 during the course of an exhaustive examination of the fauna of a 

 small tank (pond) in the neighbourhood of the Presidency 

 College discovered and drew my attention to numerous green 

 " egg-like " bodies, of about -^^ inch in diameter, which were 

 to be seen on the surface of the finely divided mud. 



These bodies proved upon examination to be Rhizopods be- 

 longing to the remarkable genus Pelomyxa, and forming a 

 new species of that genus, but diflFering in some important 

 particulars from all hitherto described Rhizopods. I propose 

 to call the species P. viridis. 



The species is peculiarly interesting not only on account of 

 its great size (it is larger than any known form of the Lobosa), 

 but also on account of the presence of chlorophyll and symbiotic 

 bacteria,^ and the assistance which this renders in the study of 

 its protoplasm. 



* The rod-like bodies here regarded as bacteria were described as crystals 

 of unknown composition by Greeff in his account of Pelomyxa palustris. 

 Leidy describes them as exhibiting transverse striatious. The symbiosis of 

 bacteria and amoeboid Protozoa has a special importance at the present 

 moment in connection with Metschnikoff's doctrine of Phagocytosis. 



