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liaematoxylin. In this manner some beautiful preparations of the 
stages of development of the gregarine were obtained, and it was in 
this material that I have followed out the development. Unfortunately 
there are one or two gaps in this development owing to the fact that 
insufficient material had been collected, but certain stages can only be 
obtained by the examination of large quantities of material in the 
manner described above, a process which is very tedious. 
In the gut the free forms are usually about 50 yu, in length or 
smaller. I have not encountered such large forms as those described 
by Ross as being 200 /r, long. When examined in the living condition 
Lanliesteria cuUcis of Stegomyia fasciata. 
Figs. 1 and 2. Gregarines free in the gut of the larva of Stegomyia fasciata. 
Fig. 3. Gregarine attached to epithelial cell. 
they exhibit the typical gregariniform movements of progression, 
flexion, and constriction. Such free forms are figured at Text-figs. 
I and 2. In sections of the gut it is found that the gregarines remain 
as intracellular parasites during nearly the whole of their trophic 
development. PI. XV, fig. 5 shows a gregarine completely within its 
cell, and fig. 8 another 50 /r long, also within the epithelial cell which 
shows a slight rupture at the surface. The general shape and features 
of the gregarine call for no special remark. They are clearly shown in 
the figures. The body is non-separate and the single and typical 
gregarine nucleus is at the centi’e of the body. At the anterior end of 
the body is a peculiar structure which reminds one of the similar body 
described by Siedlecki in Lankesteria ascidiae. It appears to be 
a ve.sicle and is possibly a suction organ connected with the endoplasm 
through a pore in the cuticle. It evidently functions as an organ of 
fixation which is used chiefly when the epithelial cell is completely 
ruptured and the gregarine remains attached to its degenerate 
remnants. The most careful examination of the point of fixation of 
the gregarines in sections has failed to reveal any processes or fibres 
passing from the fixation organ into the epithelial cell. The gregarine 
lies in a vacuole in the epithelial cell and the fixation organ is merely 
Parasitology iv 21 
