388 MUS. L. J. VELEY — CONTRIBUTION TO TUE 



The reactions with three out of four tests were, then, perfectly 

 definite, and the conclusion reached was that the refringent 

 bodies are certainly proteid in nature, and are probably some 

 form of albumin, the product of metabolism in the protoplasm 

 of the animal. 



It may be mentioned that the reaction with picric acid in 

 turpentine described in my previous paper in the ' Quarterly 

 Journal of Microscopical Science ' is consistent with those obtained 

 as above, since the peculiar "bright crescentic areas " produced 

 in the refringent bodies by that stain only, may have been the 

 " local bead-like coagulations " said to be given when crystals of 

 picric acid are dissolved in solutions containing albumin. 



The Relation of the Refringent Bodies (a) to the Bacteria, 

 (b) to Pelomyxa. 



(«) That the refringent bodies certainly aiford to the bacteria 

 a point of attachment without which the cycle could not be 

 completed has been already explained. It seems, however, 

 most probable that the relation is a twofold one, and that the 

 refringent bodies serve them also as a food-supply. For the 

 bacteria are found to settle upon the refringent bodies in 

 numbers, in preference to other solid bodies of which plenty are 

 always accidentally present in the protoplasm of Pelomyxa ; 

 growth has been proved to take place while this relation 

 continues : further, the facts that the bacteria swarmed upon 

 the albuminous ova of Hotifer in exactly the same manner 

 as on the bodies, and that they have been proved to live 

 and flourish in albuminous media, lend great support to this 

 view. 



(h) The relation of the refringent bodies to the Pelomyxa as 

 a whole is extremely difficult to determine, and must perhaps 

 remain an open question. Two views are possible, and either 

 is rather plausible : — (1) the refringent bodies may be a reserve 

 food-supply to the animal itself; in this case one would expect 

 it to be drawn upon when other food was unobtainable. Several 

 experiments were undertaken with the object of testing this : 

 many Pelomyxcs were kept in clean water without mud or food 

 of any kind, but none survived more than a few days, and 

 in these the refringent bodies were not diminished in size ; 

 in control experiments in which Pelomyxce were kept in clean 



