﻿182 Proceedings of the Royal Physical Society. 



method of exit, modifications, due probably to the relative 

 sizes of the animals, the rapidity of growth, and the 

 elasticity of the cyst-wall, occur very frequently. Thus 

 Fig. 3 shows the early stage in the case of a rather more 

 massive animal. Here the cyst has burst at once through- 

 out the whole thickness of its wall, and the parasite is 

 simply growing out into the surrounding tissue. The 

 empty cyst here will be a hollow sphere broken at the 

 place of emergence of the parasite. These empty cysts 

 very usually become filled up with intrusive connective- 

 tissue cells. This process of filling up is a common 

 occurrence, and all the different stages can easily be 

 traced in well-infected tissue. Sometimes the intruding 

 cells, in the case of a nodule of long standing, may be 

 separate cells, and may keep their separate condition for 

 some time. At first sight these were rather bewildering 

 appearances, suggesting some extraordinary form of spore- 

 formation. A little study, however, soon betrayed their 

 true origin, and they proved in every case to be quite 

 unmistakably intrusive connective tissue. Fig. 8 illustrates 

 this point. 



Two courses seem to be followed by the issuing parasite. 

 It may break up almost at once into a number of small 

 bodies usually containing two nuclei ; this process is 

 shown in Figs. 9 and 10. These are drawings of two 

 consecutive sections, and depict an animal which has 

 broken up immediately upon issuing from the cyst. These 

 little bodies become distributed over quite a small area, 

 usually inside the original connective-tissue nodule, and 

 appear to start growing pretty soon. Sometimes they seem 

 to become intracellular, but I cannot be sure upon this 

 point. The connective tissue in the nodule proliferates, 

 and the little parasites thus become separated from each 

 other, often each of them as their size increases becoming 

 the centre of a nest of connective-tissue cells. Large sub- 

 sidiary nodules may be formed which project out from the 

 edge of the original one — a circumstance which accounts 

 for the multiple character of the tumours, as seen from an 

 external examination of the liver before sectioning. The 



