252 TRANSACTIONS OF THE CANADIAN INSTITUTE. | VoL. 1. 



II. On Chromatophagous and other Intracellular Parasites 

 IN the Intestine of Necturus Lateralis. 



In the intestinal epithelium of Necturus are often found forms which, 

 from their peculiarities, must be regarded as parasitic. When I observed 

 them first, I considered them to belong in a general way to that class of 

 intracellular structures which Lukjanow* has described as occurring in 

 the gastric mucosa of the salamander, and of which there are not a few 

 examples in the intestine of Necturus. They are well shown in prepara- 

 tions made from recently captured animals, and their characters are pre- 

 served well in the tissues fixed with Flemming's Fluid, or corrosive sub- 

 limate, and stained with alum cochineal, or haematoxylin or eosin. 



The chromatophagous forms have usually an irregular outline and the 

 protoplasm extended in one or more long pseudopodial processes, which 

 taper often to fine threads. In some cases the whole organism is thread- 

 like (Fig. 15/). They are easily distinguishable in alum-cochineal pre- 

 parations in the unstained, epithelial cytoplasm, in which they may be 

 found, and by their stain being in every respect similar to, and as deep 

 as, that of the chromatin bodies of the epithelial nuclei. With high- 

 powered objectives the stain is seen confined to the fine granules which 

 densely crowd the cytoplasm of these organisms. There is sometimes 

 a quantity of unstained protoplasm at the thicker end (Fig. 14/), or 

 a more or less curiously shaped mass may lie in its neighborhood 

 (Fig. \6 pr). Sometimes the bodies are found in the interior of nuclei, 

 but, as a rule, they are not easily recognizable in this position, unless they 

 show amoeboid outlines or are fixed in the act of migrating from the 

 nucleus. One is shown in the latter condition (Fig. 15/). The nucleus 

 is in this case partially deprived of its chromatin by the parasite, which 

 owes its staining capacity to the chromatin it absorbs or invaginates. 



An explanation of the relations of such structures as are shown in Fig. 

 13 (/) can be at best only problematical. Here two parasites, each in a 

 separate cavity m the cytoplasm, have their prolongations hooked 

 around one another. This is only one of several instances observed of 

 such a condition, but the preparation drawn shows the process most 

 distinctly. It may be a case of conjugation. 



There are a number of forms which are either wholly unstained by the 

 coloring reagent, or which possess one or more stained spherules or 

 granules (Fig. 13/). These may, in some cases at least, represent young 

 stages of the chromatophagous forms. 



*L. c. 



