204 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 



process of division. So)no divide into 2 equal parts (lig. 8) ; in others the parts are 

 of unequal dimensions (liffs. 0, 10), and often this division recalls strongly a phe- 

 nomenon of terminal or lateral budding (iig. 11). 



Spore. — Very refringent, pyriforra; anterior end mucli more acute; 

 length 5 to G //; sliell with very fine h)n,i;itu(linal striaj; coiikl not deter- 

 mine wliether bivalve or not. 



Capsule : In fresh material the highest powers reveal nothing suggest- 

 ive of a capsule, the anterior extremity appearing merely more shaded, 

 seeminglyoccupiedbyahomogeueous, refringent substance. Onesome- 

 times sees, however, near the anterior end, a clear streak (pi. 12, lig. lo) 

 believed to be due to the capsule, but it is too indeQnite and exceptional 

 to prove the existence of that structure. Stained sections afford no aid 

 here. 



Filaments: Extrusion not produced by iodine, potassium or sodium 

 hydrates, glycerin, heat, acetic or formic acids, or by ether. Hydro- 

 chloric and nitric acids produced extrusion; the latter difiBcultly obtain- 

 able, observed only in a very small number of cases in spite of repeated 

 efforts. Strangely enough, this method failed completely to produce 

 extrusion in T. octospora and, on the contrary, ether, the only agent 

 which succeeded in that species, was without effect on the spores of T. 

 giardi. Filament 15 to 20 /^ long; usually extruded completely, some- 

 times, however, extruded only partially uncoiled; susceptible toanilin 

 stains, among others violet 5B. 



Sporoplasm : Safranin or gentian violet (apparently the best stains 

 for these organisms) yield 2 different appearances, according to the 

 degree of decoloration. If slightly decolorized, the vacuole alone is 

 visible, but when decolorized ad maximum only some colored grains 

 remain in front of the vacuole. Sometimes two or three are distin- 

 guishable; most frequently, however, only a small colored band (appa- 

 rently formed of fused granules of indeterminate number) is seen. 

 Vacuole aniodinophile. 



Habitat.— Seen only once in Grangon vulgaris Fabr. (shrimp), from 

 Boulogne. Probably the course of development is the same as in 

 Palcemon, as in the single specimen taken the state of development of 

 the parasite corresponded to the state of development in Palcemon at 

 the same date. 



Patlioloyy. — Everything under T. octospora relative to the opacity 

 produced in the host applies equally to T. giardi, except that, by reason 

 of the less perfect normal transparency in, and the pronounced tegu- 

 mentary pigmentation of, Crangon vulgaris, the modification is less 

 striking, though it is always sufficiently sharp to permit the recogni- 

 tion of the infected individuals without any difficulty. 



Effects. — Ehrenbaum^ noted abnormal individuals of a paler, more 

 opaque color, destitute of the normal greenish tone, apparently con- 

 siderably enfeebled, dying more rapidly than the normal ones when 



'Zur Nalurgeschichte von Crangon vulgaris, Berlin, 1890, pp. 11, 12. 



