A. Porter 
373 
The endoplasm as before stated is fairly granular. At times in 
living specimens, the granules are so arranged as to suggest the presence 
of a cytopharynx between them. But further observation of the living 
creature showed the obliteration of this feature after a short time, and 
I was very rarely able to find it in fixed and stained preparations 
(PI. V, Fig. 22). Leger (1902) has described such an “intestinal canal ” 
in the Herpetomonas of the Nepa he examined, but I have never been 
able to establish definitely its existence in the parasites of the British 
Nepa. But on several occasions I have seen a markedly clear area 
(Figs. 25, 28) near the posterior end of the parasite, such a vacuole 
(function undetermined) having been described by Ldger. 
The nucleus 1 is usually oval in form, its long diameter coinciding 
with that of the body. In the early flagellate stages, the nucleus is 
fairly compact, but as growth proceeds, it becomes more vesicular 
(PI. V, Figs. 21, 22, 25) and its chromatin takes the form of small 
gi'ains scattered through the general nucleoplasm. In some fully 
developed flagellates about eight masses of chromatin are present 
(Figs. 28, 31, 34, 36). I have not been able to establish any definite 
number of chromosomes for the nucleus of H. jaculum as Patton (1908) 
was able to do for H. lygaei, but I agree with Leger that there are a 
number of chromatin grains present. Possibly this is due to the fact 
that division of H. jaculum is initiated extremely early, and the finely 
divided condition of the chromatin is one well-suited for equal distribu¬ 
tion of chromatin between the daughter forms resulting from division. 
The blepharoplast (kinetonucleus) is comparatively large and stains 
very deeply. A clear area is often seen around it (PI. V, Figs. 16, 
18, 28). It is usually rod-shaped (Figs. 19, 22, 28), sometimes slightly 
curved (Figs. 30, 31). It may be placed at right angles to the long 
axis of the body (Figs. 22, 25) or may be inclined at an angle to it 
(Figs. 19, 32). On one occasion I found several specimens of H. jaculum 
with the blepharoplast lying parallel to the long axis of the body 
(Fig. 24), but this is most uncommon. The blepharoplast is almost 
invariably situated in the pre-nuclear region of the body of the parasite. 
In division the blepharoplast becomes dumb-bell shaped and constricts 
into two (Figs. 37, 38), while in encystment it approaches the nucleus. 
I have frequently seen constriction of the blepharoplast into two, but 
1 Throughout this paper the terms nucleus and blepharoplast have been used to denote 
the two chief chromatin bodies of the parasite, for these terms have been used consistently 
by practically all workers on Herpetomonas and Crithidia and thus have received in¬ 
ternational recognition. 
Parasitology ii 
24 
