THE PROTOZOA PARASITIC IN ARCHOTERMOPSIS WROUGHTONI 251 
plasm is clearer than that of the rest of the body. The large 
food particles are aggregated at the posterior two-thirds of 
the body, and are always found behind the nucleus, as in 
Trichonympha. This is, however, in sharp contrast 
to Grassi’s experience, for, in his last paper (7), he states that 
in the Pseudotrichonympha the food particles are not 
limited to the posterior extremity, but on occasion may be 
seen in the region of the anterior organ ‘ mamella’. Buscalione 
und Comes (1), in their paper, state that when treated with 
iodine dissolved in iodide of potassium, the region, near to 
the nucleus, in Trichonympha, gives the characteristic 
reaction of glycogen, and that this reacting region is sharply 
defined from the rest of the body. In P. pristina, however, 
the glycogenic reaction is diffused through the whole body, 
being greatest behind the nucleus. This reaction and the 
results of other microchemical tests will be fully discussed 
in a forthcoming paper. As regards the method of food 
ingestion I can supply no evidence beyond the fact that I have 
been unable to find any trace of the peculiar process described 
by Porter (24) in T. agilis. Kofoid and Swezy (18)— 
apparently with reluctance—conclude that in Tricho- 
nympha campanula the anterior organ (centroblepharo- 
plast) may function also as a cytopharynx ; a view also held 
by Buscalione and Comes. A grave objection to this conclu- 
sion 1s that food particles are never found in the anterior region 
of the body; Kofoid and Swezy themselves say, ‘ the anterior 
region of endoplasm has, in all individuals observed, been 
entirely free from food bodies or vacuoles, with the exception 
of small darkly-staiming rodlets which may be bacteria or 
possibly chromidia’. This has been the experience of all 
workers on Trichonympha, and Pseudotricho- 
uympha pristina offers no exception to this rule. As 
Porter says, ‘it seems highly improbable—to say nothing of 
the absence of any trace of a permanent oral structure—that 
solid food should pass through this anterior region so quickly 
that not a single case of its passage, or of its presence in this 
part, should have been discovered by any of those who have 
