408 



THE FORMS OF CELLS 



[CH. 



of unduloid form. It has been shewn lately, in one or two 

 instances at least, that species of Vorticella may "metamorphose" 

 into one another : in other words, that contours supposed to charac- 

 terise species are not "specific" These VorticelUd unduloids are 



>^- 



Fig. 124. Various species of Vorticella. 



M 



Fig. 1 25. Various species of Salpingoeca. 



Fig. 126. Various species of Tintinnus, Dinohryon and Codonella. 

 After Saville Kent and others. 



not fully symmetrical ; rather are they such unduloids as develop 

 when we suspend an oil-globule between two unequal rings, or blow 

 a bubble between two unequal pipes. For our Vorticellid bell hangs 

 by two terminal supports, the narrow stallj to which it is attached 

 below, and the thickened ring from which spring its circumoral 

 cilia; and it is most interesting to see how, when the bell leaves 



