230 The Philippine Journal of Science ms 



tion gives way to what Hadley styles a form of "autogamous 

 reproduction." This he has not worked out in all its details, 

 and I am unable to determine if it is autogamy or merely mul- 

 tiple division within a cyst, although he mentions the casting 

 off of nuclear material, which might be interpreted as a process 

 of nuclear reduction. The fusion of gametic nuclei, such as 

 has been described by Wenyon(5i) for Entamoeba muris, is not 

 mentioned by Hadley, but he speaks of the possible conjugation 

 (copulation?) of flagellates derived from the original tropho- 

 zoite. These flagellates might be in the nature of swarmers 

 produced after the reduction process spoken of by Hadley, or 

 they might be trophozoites undergoing copulation as has been 

 described by Dobell in the case of Copromonas subtilis. Schau- 

 dinn in short note, (45) has stated that Trichomonas becomes an 

 amoeba and that two of these amoebae, after giving off reduction 

 nuclei, encyst together and carry out syngamy within the cyst. 

 Later the zygote breaks up, forming small individuals, leaving a 

 mass of residual protoplasm behind. However, this has not 

 been confirmed, and indeed the whole process of syngamy in 

 Trichomonas remains to be worked out, as does the same problem 

 in the larger number of intestinal protozoan parasites. 



In the process described by Hadley, the trophozoite usually 

 increases in size, rounds off, and secretes a cyst. The parabasal 

 body lengthens, until it forms almost a complete circle near the 

 periphery. The flagella, undulating membrane, and cytostome 

 are gradually lost, and the vacuole or vacuoles of the trophozoite 

 coalesce and enlarge until the single vacuole occupies the greater 

 portion of the ventral part of the animal. The cytoplasm and 

 nucleus are flattened against the dorsal wall. The chromatinic 

 blocks and axostyle degenerate and disappear. The parabasal 

 may persist with the blepharoplast for a time, but eventually 

 they, too, disappear. 



At this stage the vacuole, which is held to contain the store 

 of reserve food, has increased in size, until it occupies the larger 

 part of the cell and is surrounded by a crescentic ring of cyto- 

 plasm, which seemingly has become much reduced in amount. 

 The nucleus is flattened or flask-shaped and divides, the daughter 

 nuclei taking up positions at opposite sides of the food vacuole. 

 At this stage the organism certainly bears a striking resemblance 

 to Blastocystis and to the figures in Chatton's recent paper. The 

 nuclei may then divide to form four, eight, or sixteen daughter 

 nuclei, which arrange themselves about the periphery. 



Hadley mentions at this point that smaller portions of nuclear 



