BALANTIDIUM HAUGHWOUTI, NEW SPECIES, PARASIT- 

 IC IN THE INTESTINAL TRACT OF AMPULLARIA 

 SPECIES, A MORPHOLOGICAL STUDY 



WITH REMARKS ON THE RELATION BETWEEN THE MEGANUCLEUS 

 AND THE MICRONUCLEUS ' 



By Walfrido de Leon 



Instructor, Department of Pathology and Bacteriology, College of Medicine 

 and Surgery, University of the Philippines 



ONE PLATE AND FIVE TEXT FIGURES 



INTRODUCTION 



This is a study of the structures and the characters of what 

 appears to be a new species of Balantidium found parasitic 

 in the intestinal tract of a fresh-water snail, Ampullaria sp. 

 The parasites were first seen by Prof. Frank G. Haughwout in 

 the original host found in the pond on the ground of the Bureau 

 of Science, Manila. 



The host, Ampullaria, is a very common inhabitant of fresh 

 waters in the Philippine Islands. It thrives luxuriantly about 

 the banks and the bottoms of shallow rivers and ponds. It 

 is known in the vernacular as "cohol" and is much used as a 

 food by the Filipinos. 



The discovery of this species is of some systematic interest 

 in that it forms an addition to the species of Balantidium that 

 have been found infesting invertebrate hosts. 



THE GENUS BALANTIDIUM 



The genus Balantidium was founded by Claparede and Lach- 

 man. (10) It consists of heterotrichous ciliates, free-swimming 

 or histozoic, oval in shape, slightly truncated anteriorly and 

 more rounded posteriorly. A small triangular excavation, an- 

 teriorly, forms the peristome at the bottom of which opens the 

 cytostome which leads backward into a fairly well-developed 



1 Prom the department of parasitology. Submitted in partial fulfill- 

 ment of the requirements for the degree of Doctor of Tropical Medicine, 

 Graduate School of Tropical Medicine and Public Health, College of 

 Medicine and Surgery, University of the Philippines. 



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