54 B. GRASSI AND A. SANDTAS. 



chylific ventricle, or may perhaps multiply therein before 

 entering the proctodseum. 



I propose to return to this point in a future work, in which 

 I shall deal more particularly with the minute structure of the 

 protoplasm and nucleus in these Protozoa. 



The various rods and rodlets of these parasitic Protozoa, as 

 well as the dense and granular protoplasm of Trichonympha, 

 evidently serve as an endoskeleton for the support of the body 

 and protection of the nucleus. This is shown by their entire 

 absence in Holoraastigotes, the only form in question that 

 does not take in solid food-particles (fragments of wood), which 

 would seriously endanger the nucleus. 



The special apparatus at the anterior extremity of Tricho- 

 nympha allows it freely to thread its way through the 

 surrounding swarms of its own and other species without 

 compression of the nucleus, to which the mamilla acts as a 

 sort of buffer. I have sometimes thought that the structure 

 in question may have the further function of a sucker, by which 

 the animal can attach itself to the intestinal walls. The 

 papilla of Pyrsony mpha is probably similar in function. 



As I have previously said, all these parasitic forms must be 

 classed among the Flagellata, and cannot be referred to the 

 Ciliata, chiefly owing to the absence of a micronucleus (para- 

 nucleus) . 



The Lop horn on ad id 86, in which a large area of the body 

 is covered with flagella, evidently form a family osculant 

 between the other Flagellata and the Pyrsonymphidse, in which 

 the entire surface is thus covered. 



The presence of the endoskeleton is the principal reason 

 which leads me to associate all these forms with the group of 

 Flagellata. 



Catania; October, 1890. 



