ON A NEW RHIZOPOD PARASITE OF MAN. 



91 



sarcode were not of sufficiently fluid nature as to allow of a far-reaching change 

 in the body-form. So then, Am. miurai must be said as being of a very sluggish 

 habit. On this account and from consideration of certain fact to be mentioned 

 further on but which indicated that the Amoeba was not fit for prolonged existence 

 in the serous fluid containing it, I have naturally questioned myself if the forms 

 I have considered as normal and healthy were really such and not already in the 

 first stage of contraction. But I thiuk this doubt can be done away with as being 

 unfounded, for, were the animal in any way pathologically aflk-ted, the power of 

 emitting and retracting those delicate psendopodia on the knob should be the 

 first to disappear. 



The enclosures in the main body are the nucleus, the vacuoles and the 

 minute oil like corpuscles. They occur in the finely granular sarcode without 

 any definite rule as to their positions. 



The nucleus is generally invisible in the fiesh or living state, at most only 

 indistinctly indicated by an ill-defined, somewhat clearer space in the sarcode 

 (figs. 1 — 5). When treated with the acetic acid, it comes forth with all the desi- 

 rable distinctness (figs. 6,7 & 9). It occurs in twos or threes almost as often as 

 it dots in a single number. Round, oval or kidney-like in shape, it is bounded 

 by a distinct nuclear membrane. The diameter measures 8 — 15 /u. The nuclear 

 fluid is faintly granular, somewhat clearer than the sarcode and encloses within 

 one or more prominent nucleoli, generally one in number. 



The vacuoles are perfectly clear and form very conspicuous objects in fresh 

 specimens, being very sharply outlined against the sarcode. They are inconstant 

 as to their number and size. In some, notably smaller, individuals (fig. 5, a & c; 

 fig. 6), they were found to be even entirely missing. But the majority of individu- 

 als showed them in numbers of one, two, three or several (see figs.). I think 

 none of these vacuoles is pulsatile. Once a vacuole in a specimen, the first 

 examined from a freshly taken abdominal fluid, was seen to vanish from view as 

 slowly as it again reappeared ; but then I was at a loss to decide, whether or 

 not, the phenomenon was simply due to that vacuole getting alternately ii to and 

 out of the focus as the object slowly rolhd abuut under the cover-glass. Treated 

 with acetic acid, the vacuolei lose the boldness of contour, while the large vesicu- 

 lar nucleus, hitherto concealed, is made perfectly clear. In the number, size and 

 non-contractility of the vacuoles the present species seems to agree exactly with 

 Am. fluida as described by Greeff. 



