16 SYNOPTIC COLLECTION. 



PI. 3, fig. i, represents one of the smaller cytodes. 

 showing the blunt pseudopodia, and PI. 3, fig. 2, one of 

 the larger cytodes in the form of an irregular network with 

 the imbedded coccoliths, greatly magnified. The indefi- 

 nite form of the cytodes, the, absence of organs and outer 

 covering, and the possession of blunt pseudopodia, to- 

 gether with the fact that movements have been observed 

 in the protoplasm, suggest the possibility that we have 

 here a vast number of marine Protamoeba-like organisms; 

 but more investigations on the Bathybius are needed be- 

 fore its exact nature and relations can be determined with 

 certainty. It was called a mineral deposit by Wyville 

 Thomson, its discoverer, but was considered an organic 

 form by Huxley and Haeckel. 



If now the crawling marine Protamoeba should adapt 

 itself to the life of a free swimmer in the open sea, we 

 might expect to have as a result a form not unlike Pro- 

 togenes primordialis Hkl. (PL 4, fig. i). The flattened 

 body of the creeping Protamoeba would tend to become 

 more or less spherical when suspended in the water and 

 the simple, blunt, ever-changing pseudopodia might de- 

 velop into the long, branching, and more constant pro- 

 pelling organs which enable the animal to swim rapidly 

 through the sea. Be this as it may, we certainly recog- 

 nize in this unnucleated Protozoan specialization of 

 structure and function, and we find a correlation existing 

 between habit and structure. If we could find a young 

 form (PI. 4, fig. 2 ) 1 similar to Protogenes, which after 

 growing to adult size divided by fission, and if these 

 zoons,' 2 instead of separating, remained together for a 

 time at least, connected by their branching and anasto- 

 mosing pseudopodia, then we should have a colonial form 

 like Myxodictyum sociale Hkl. (PI. 4, fig. 3). Here we 



1 It is probable, although not proved, that Myxodictyum sociale 

 Hkl. arises by the detachment of single animals like PI. 4, fig. 2. 



2 Zoon is substituted for individual. For reasons, see Hyatt, 

 " Larval Theory of the Origin of Cellular Tissues," Proc. Boston 

 Soc. Nat. Hist., XXIII, 1884, p. 46. 



