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Oriental Sore 
which pi’oceed with their development in the body of the tick Rhipi- 
cephalus sanguineus. The larger forms represent the asexual method of 
multiplication or schizogony. 
A similar difference in the reproducing forms of other haemogregarines 
has been noted by Lutz, Prowazek, Reicheuow and others, and I have 
described it in the case of Haeniogregarina gracilis of the Sudan lizard, 
Mabuia quinquitaeniata. I suggested there that the small narrow forms 
which entered the red blood corpuscles and appeared in the peripheral 
blood were possibly sexual forms which would be found to pursue their 
further development in soine intermediate host. This has been fully 
borne out by recent investigations. In their recent paper on the 
development of Haeniogregarina lutzi Hartmann and Chagas describe 
a similar course of development. They mention the case of the Haenio¬ 
gregarina gracilis described by me, but they have stated that the 
so-called “ microschizogony ” products are the only form of asexual re¬ 
production. In reality I said that the small forms are those destined 
to enter the red corpuscles and to appear in the periphei’al blood while 
the large forms remain in the liver and reproduce asexually. The 
former are then probably sexual forms. The macroschizogony forms 
in the lizard as in the dog represent the asexual generation which 
occurs only in the internal organs, the so-called macromerozoites never 
appearing in the peripheral circulation. 
The various stages of the development can be traced in sections of 
the spleen or bone marrow. In the present instance the tissue was 
fixed in Zenker’s fixative and the sections stained with iron haematoxylin. 
The youngest forms are seen as small rounded bodies within mononuclear 
cells (PI. XVI, figs. 4 and 13). The nucleus has a structure similar to 
that which has been described for the haemogregarines of the peripheral 
blood. The parasite increases in size and distends the host cell. At 
the same time the protoplasm alters in appearance, becoming filled w'ith 
spheres of a retractile material. Very soon the nucleus commences to 
divide. The nuclear membrane is lost and the chromatin is arranged 
in an irregular mass of granules. With prolonged differentiation in 
iron alum solution it is seen that a karyosome is present in the midst 
of these granules. The karyosome divides after becoming elongated, 
and with its division the chromatin becomes collected into twm masses 
each with its own karyosome (PI. XVI, fig. 9). The karyosome acts in 
exactly the same manner as the karyosome of Coccidium schubergi in 
the dividing nuclei of the schizont as described by Schaudinn. Hartmann 
and Chagas have described a very similar nuclear division in the case of 
