340 T. B. ROSSETER ON CYSTICERCUS QUADRICURVATUS. 



Taenia of this particular Cysticercus is up to the present time 

 unknown, these conclusions have been arrived at ? 



The above observations have been made and conclusions 

 arrived at from the following facts : Care was taken in 

 causing the expulsion of the formative substance within the 

 cyst. This having been obtained by the nitric acid process, a 

 matter of some delicacy owing to the immature scolex being 

 deeply seated within the cyst, abetter opportunity was afforded 

 to study the formative substance and the hooks. But little 

 can be said of the former owing to the homogeneity of the sub- 

 stance, the emitted contents being seemingly a mass of plasma 

 (see Fig. 4), only that the application of ether by dissolving the 

 minute fatty globules gave the opportunity of differentiating 

 the tissues of the rudimentary rostellum. A searching exami- 

 nation with a ^ revealed the fact that amongst this homogeneous 

 mass was a tract of fibrous tissue (Fig. 4a). This tract was 

 quite distinct from the surrounding granular substance which 

 would have constituted the embryonic scolex of the Cysticercus 

 or future Taenia, and it ran upwards and curved round until it 

 reached the aggregated dense mass on which the hooks 

 were situated — the future rostellum — where it was lost to 

 view. 



The position of tbe hooks as well as their formation in 

 this, the cysticercoid, is exactly the same as that in the 

 Taenia stage, and it is from this circumstance that one is 

 enabled to determine their position in the mature scolex, as 

 well as the species of Taenia to which the Cysticercoid will, 

 when transferred to its final host, become the perfect scolex 

 with its fertile proglottides. 



I have invariably found that when the expelled rudimentary 

 scolex is compressed, either with a lever compressor or under a 

 cover glass with needles, the hooks are expanded to their 

 utmost limit, and when the pressure is taken oft' they revert 

 again to their former position, but if pressure is insisted on 

 they instantly become separated in all directions. Such, how- 

 ever, was not the case in this instance, for apply what pressure 

 one would they did not separate, but seemed welted or bound 

 together back to back by some ligamentous process. Advan- 

 tage was taken of this phenomenon to further explore the 

 somewhat indefinite termination of the muscular tract, and to 



