382 MRS. L. J. YELET CONTRIBUTION TO THE 



upon refriugent bodies as a support, possibly also deriving food 

 from them ; if this were the case, it ought to be possible to find 

 some evidence of it, if a sufficiently large number of Pelomyxce 

 could be examined. 



After the examination of a great many fresh preparations, in 

 which JBelomyxcB were teased up in water and their; contents 

 carefully studied, I was fortunate enough to obtain one in which 

 several single filamentous growths occurred, each attached to and 

 springing from one refriugent body. They were composed of a 

 single rigid slighfcly-curved chain of joiuted rods exactly similar 

 to the characteristic jointed rod of Pelomyxcs ; the joints, of which 

 there were 20-30 in a single growth, were of the same thickness 

 and length as the free rods and stained in a precisely similar 

 manner, leaving the tine single-walled sheath colourless and 

 barely visible. 



They are figured in PI. 36. figs. 1, 2, which are reproduced from 

 photomicrographs by Dr. G. Mann. One or two showed pseudo- 

 branchiug (fig. 1). Later on in the course of my researches, a 

 fully-developed pseudo-branching filamentous growth, attached 

 by its base to a single ref ringent body, was teased out of a fresh 

 JBelomyxa and is figured on PI. 36. fig. 4. Also on several 

 occasions a live Pelomyxa under observation was seen to eject a 

 complete branched system of this kind, the eftbrt to get rid of so 

 large and rigid a body often resulting in the " bursting " or 

 disintegration of the animal. 



The branched systems so ejected ultimately broke down to 

 form 2-jointed free rods. A preparation was made of one such 

 ejected growth, which exactly resembled those previously 

 described and figured, and stained well with iron-hsematoxylin. 

 It seemed clear that I had obtained two of the later stages of 

 development, but the earliest stage, viz., the free unit fixing on 

 a refriugent body, had not as yet been found. The observations 

 were extended to a great number of Pelomyxce in the hope of 

 tinding this also, and eventually success was attained. 



In a teased preparation a single 2-jointed rod (double unit) was 

 seen to fix itself by one end to a refriugent body. A minute 

 " blob " of secretion appeared to be formed at the point of attach- 

 ment, which fixed the rod firmly to its support. (PI. 36. fig. 5.) 



Later, other rods were observed to fix in the same way. 



Any slight jolt or vibration occurring before the secretion had 

 become firm was sufficient to dislodge the bacillus, but at a later 



