324 
Herpetomonas patellae, n.q). 
gland of the limpet were fixed wet in Bonin’s fluid, in osmic acid vapour 
followed by absolute alcohol, or in formalin vapour. They were 
stained by Delafleld’s haematoxylin, by glycerine haematein or by 
Giemsa’s solution. Fixation by Bonin’s fluid, followed by haema¬ 
toxylin staining was best. 
The parasite exhibits the usual three phases common among 
flagellates in its life-cycle. 
A. Pre-flagellate forms. The pre-flagellates (Fig. 1) are ovoid 
bodies measuring from 2 p. to 3 ju. long, and are about 1 p to 1‘5 p broad. 
The nucleus is oval, showing sometimes a central karyosome (Fig. 2), 
but more often having the chromatin evenly distributed (Fig. 1). 
Figs. 1-3. Herpetomoiias piatdlae. Pre-flagellate. developing young tiagellate and 
dividing pre-flagellate forms, x 3000. 
The blepharoplast is baiiike and homogeneous. Some specimens 
showed a chromatophile area from which the flagellum develops. The 
growing pre-flagellate shows an elongation of the end near the blepharo¬ 
plast. A chromatoid thread is gradually differentiated, which pushes 
the periplast forward and then projects as a free flagellum (Fig. 2). 
B. Flagellate forms. The flagellates (Figs. 4-10) measure from 
5 p to 7 p in body length and are about 1 p broad. The free flagellum 
is sometimes somewhat longer than the lanceolate body (Figs. 7-10). 
8 
9 
10 
Figs. 4-10. Herpeto7nona.s patellae. Various aspects of the flagellate stage, x 3000. 
