793 



related to ihe ionic valency of the salt, then the order K,SO^— KOI 

 and KXOj — Ca(NO,), wliich has been found, is explicable. 



It is further remarkable, that the curve for K^SO^ (fig. 1) reaches 

 80 far into the alkaline region, while the curve which might have 

 been plotted for Ca(NO,)j ') would chiefly come to lie in the acid 

 region. 



The influence of the small salt concentrations, as well as that of 

 ionic valency point to a possible correspondence between the pro- 

 <"esses which occur in the change of motility of Cklamydomonas 

 and the process of the flocculation of suspensoids. 



The influence of salts on the condition of emulsoids often suggests 

 an arrangement of the ions in definite series. For the anions there 

 is the series of Hofmeisteh. In a process, occurring in accordance 

 with these ionic series, the influence of the salts is said to be 

 lyotropic. 



It was therefore desirable to see, whether the influence of salts 

 on the motility of Chlamydoiiionas is one according to the lyotropic 

 series. This was only investigated for the anions. F'or algae from 

 one and the same culture the following series was found: 



Kl < KNO, < KOI < KBr, KC^S. 



This was by no means the order of anions, if the influence of 

 the salts had been lyotropic, for then it would have been 



KOI < KNO, < KBr < Kl < KONS. 



We must not attach too much value to this lesult. The ionic 

 series is reversed, when the medium becomes acid instead of alka- 

 line, while in neutral solutions transitions between the alkaline and 

 the acid series are found. 



The observations on ChlamydoDWnas were carried out at 0.00015 

 n. KOH, N^ere there was accordingly much chance of finding one 

 of the transitional series. We were, however, obliged to work in 

 very feebly alkaline solutions, because at a different degree of acidity 

 we should be comparing for the various salts such concentrations 

 as were not, according to the curves, really comparable. In that 

 case we should have compared a maximum for one salt with a 

 minimum for another salt. In reality a good coniparison would oidy 

 be obtained for concentrations of a specified niaximum, e.g. the 

 middle one, for each of the salts. 



In any case we can say with some probability that the action of 



') The concentrations of the solutions change each time by 0.05 n. ; for this 

 reason the results were not sufficiently accurate for a curve to be traced. 



