SEA-FISHERIES LABORATORY. 97 



but were harder in their central parts. Microscopic 

 examination of this fresh tumour substance showed little 

 definite detail. There was much fat or oil present in 

 the form of small globules. Small spherical bodies 

 resembling sporozoan cysts, containing rounded cell-like 

 structures, and surrounded by definite capsules, could be 

 seen. These suggested that the tumour was one caused 

 by the enormous multiplication of some Protozoan, but no 

 spores could be seen. For the rest the substance, when 

 fresh, consisted of unrecognisable debris. 



Smears were, however, made, fixed in Zenker's fluid, 

 hardened and stained by iron haematoxylin and Orange G. 

 Some of the nodular masses were also preserved in 

 Zenker's and Bouin's fixatives, and pieces of the adjacent 

 muscle substance were cut out and fixed in the same way. 

 The tumour was then examined more attentively. It was 

 scraped out, and it was then seen that it occupied a cavity 

 in the flesh of the animal. This cavity was not bounded 

 by any capsular structure : what appeared at first to be a 

 capsule was the connective tissue muscle dissepiments. 

 Some of these run roughly concentric to the skin, and 

 those near to the latter remained, although most had been 

 involved in the substance of the tumour. They had 

 almost no muscle tissue between them, and being forced 

 together by the pressure of the growing tumour, they 

 looked like a capsule. This was, however, not the case; 

 the tumour was not delimited from the surrounding 

 tissues — it was truly malignant. 



Later examination showed clearly that it was a 

 sarcoma undergoing profound autolytic degeneration. 

 The evidence for this may, however, be stated, since the 

 conditions were very interesting. First of all we may 

 look at the stained smear. This is represented in fig. 2 

 of Plate VII; the drawing shows, not a definite field as 



