5o2 C. CLIFFOJil) DOr.FLL. 



Cristispir^e are plasmolysable. The phenomenon is so often 

 seen in organisms Avliieli have been dried, or are drying, in a 

 drop of sea-water, that it is almost inconceivable tliat anyone 

 shonlil have stated that the organisms are implasmoly sable. 

 J think there can be no doubt whatever that plasmolysis mny 

 be caused in these organisms, and that it is similar to that 

 which may be seen in niau}^ Bacteria. 



Division. — My own conclusions regarding division are 

 completely in accord with those of Schellack and dross. 

 Division is transverse, and not longitudinal. The errors of 

 interpretation which have led many workers to believe that 

 longitudinal division occurs have been fully discussed and 

 elucidated by G-ross. Fui'ther discussion of the matter there- 

 fore appears to me unnecessary. 



Polarity. — A point of considerable importance, but one 

 which has received hardly any attention from those who have 

 discussed the affinities of the Cristispir^ and similar 

 organisms, lies in connection with what I may term the 

 "polarity" of the cell. All flagellate Protozoa possess an 

 antero-posterior differentiation — that is to say, they show by 

 their movements that one end of the body is the front end, 

 the other the hind end. It is therefore correct to speak of 

 their movements as backward or forward movements. The 

 front end is usually the end which bears the flagellum. Now 

 in the Bacteria no such differentiation can be observed. 

 Spirilla and Bacilli cannot correctly be said to move backwards 

 or forwards, because neither end is definitely differentiated 

 as anterior or posterior. In other words, either end is a 

 facultative anterior or posterior end. 



In this respect Cristispira and the other so-called Spiro- 

 ch;ets are similar to the Bacteria, and stand in sharp contrast 

 with the flagelhite Protozoa. 



The point is not one to be ignored. For it is evident that 

 a differentiation of this sort must involve the organisation of 

 the whole organism, and must therefore be of profound 

 significance. 



Flexibility. — It has more than once been urged that 



