212 QUEENSLAND AGRICULTURAL JOURNAL. [1 Mar., 1898. 
generally single,* and sometimes flagellated.* Whether encysted or free it 
has usually, when single, a very decided arawboid kind of movement—vigorous 
in free bodies, and more janguid in the case of those within the cells. The 
number of organisms in any one blood corpuscle varies from a single body, or 
a single pair of bodies (which is the most common arrangement) up to six, 
and, possibly in some instances, even more. It is comparatively rare, however, 
to find more than four bodies in one cell. The blood of the general circula- 
tion, such as that obtained from a cutaneous incision, contains few infected 
corpuscles, even during the height of the fever, and such intracellular 
organisms as are present are, for the most part, of the single, amoboid, kind. 
The free amoeboid bodies, however, are generally pretty abundant in blood, 
obtained during the height of the fever, from the cutaneous vessels: sometimes 
they are quite plentiful in cutaneous blood from animals that have recovered 
(the infectivity of whose blood is known to persist for years). More frequently 
in such blood they are by no means abundant, and are then, from the absence 
of any constant and well-defined morphological characteristic, often very 
difficult to identify. Both the free and the intracorpuscular forms of the 
parasite are much better seen in specimens obtained from internal organs: the 
free ameebe in fresh preparations from the parenchyma of kidney, liver, or 
spleen, and the intracorpuscular forms in stained cover-glass preparations of 
blood expressed from the capillaries of the same organs or, preferably, from 
those of the heart’s substance.t+ 
It has been assumed, with much probability, that the different forms 
observed represent different stages or perhaps dual forms of development, and 
that the organism itself, like most cell parasites, belongs to the Gregarinide or 
Sporozoa. ‘There obviously remain, however, many points in the life history of 
the micro-organism which still require explanation. What, for instance, is the 
precise relation of the free amceboid forms to the bodies within the cells ? 
And what position do the latter occupy in the life-cycle of the organism ? 
What is their destiny, and what, if any, their further developments ? And, 
above all, what is the method of reproduction by which the micro-organism 
multiplies so rapidly in the blood of a susceptible animal—by simple fission, or 
by some kind of spore formation? and, if the latter, how and where are the 
spores produced ? 
Concerning this question of reproductive forms, Smith and Kilborne 
say:—{“No forms which might be interpreted as reproductive stages haye 
been recognised at any time in the many cases which have been studied. That 
the organism multiplies very rapidly in the blood of susceptible cattle is 
demonstrated by the fact that the injection of a small quantity of infected 
blood gives rise to the disease. How does this multiplication take place ?” 
Iu spite of this declaration of nescience, it is but fair to state that the 
insight of these excellent investigators went—as will be presently shown— 
somewhat beyond their actual observations, for they say :—S‘‘ Chere are two 
possibilities in view. Either the large pyriform body, while within the 
corpuscle or after it is set free. may enter the reproductive stage and produce 
a generation of very minute bodies akin to the motile, bright, intraglobular 
bodies seen in fresh blood, or there may be a free reproductive phase, distinct 
from the intraglobular forms, taking place in the blood. . . . Nevertheless, 
no distinctly reproductive phase has been seen during four years of observation 
of a great variety of cases.” 
Towards the elucidation of some of these matters the following obser- 
vations, made in the course of investigations carried out for the Queensland 
Agricultural Department, at Hughenden, during the past year, will it is hoped, 
to some extent, contribute. 
* Vide Fig. I. 
+ The specimens from which the accompanying figures were drawn were obtained from the 
latter situation. 
{ Texas or Southern Cattle Fever. Eighth and Ninth Reports of Bureau of Animal 
Industry, page 224. 
Report on Texas or Southern Cattle Fever, by Smith and Kilborne, pages 225, 226. 
' 
