PODOPHRYA. 



51 



Fig. 25. 



some respects similar to it, and stands in the course of the tran- 

 sitions toward the highest In- 

 fusoria. It is called Podoph- 

 rya (fig. 25). I introduce it 

 here principally because, in its 

 adult state, its character and 

 habits are strikingly like those 

 of some of the Rhizopods; for 

 instance, it seizes its prey with 

 its globe-tipped feelers (/), and 

 through them sucks the juices 

 of the victim. The same we 

 have seen is done by some of 

 the Rhizopods which live in a 

 perforated shell, (p. 14.) In its 

 embryonic state (fig. 25, A, B) it is evidently a close ally to those 

 higher Infusoria which move by vibrating cilia, and, like them, 

 the young (B) exhibit in the arrangement of the cilia an obliq- 

 uity which points to the spiral type of conformation, which, 

 as I shall show hereafter, is at the base of the organization of 

 Protozoa. What chiefly gives it a rank above those Protozoa 

 which we have already taken note of, is the definite character of 

 its contractile vesicle (cv), and the reproductive organ (n) ; both 

 of which can scarcely, if at all, be distinguished from the corre- 

 sponding organs of the highest Infusoria. In Podophrya, the 

 contractile vesicle (cv] is readily distinguishable from the rest 

 of the tissues ; nor is it, as in Actinophrys, likely to be mistaken 

 for one of the ordinary cells of the body, as it is differentiated 

 in such a manner that its physiognomy is peculiar to itself, and 

 it seems like an isolated cavity in the midst of the animal. 

 With regular precision it slowly contracts to an almost invisible 

 point, and then expands to its former rotundity, and again and 

 again repeats the systole and diastole, with ever-recurring, evenly 

 marked intervals. 



Fig. 25. Podophrya Cydopum. Clap. 300-350 diam. /, the globe-tipped 

 feelers; CD, contractile vesicle; n, the reproductive organ. A, B, the young in 

 different stages of development. After Claparede. 



