SEA-nSHERIES LABORATOEY 135 



botryoidal in form. It is difficult to describe them, but 

 the photographs convey a very good idea of their 

 appearance. The growths in the left supra-orbital canal 

 on the dorsal surface are quite similar, but part of the 

 floor of the cyst in this case is seen to be produced into 

 hard white ridges of varying form, and these can easily 

 be traced into the growth. Both in this canal, and in 

 the large cyst of the dorsal surface, the growths are very 

 firmly attached to the floor of the canal. In the large 

 cyst some of the growths have proliferated from the roof 

 of the cyst, and one of them has either broken through, 

 or has evaginated, so that it is visible without cutting 

 open the cyst. In the photograph of the ventral surface, 

 two of the growths are seen still attached to the floor of 

 the cyst. 



Nature of the Tumours. Fig. 2, PI. Ill, represents 

 part of a section of one of the smaller, white, irregular 

 growths, stained with Mallory's combination. The 

 substance of the tumour is very uniform, consisting of 

 a fine fibrous tissue containing relatively few- blood- 

 vessels. One of these blood-vessels is cut in the section : 

 it contains three red blood corpuscles and a leucocyte. 

 Outside the blood-vessel are a number of similar leuco- 

 cytes, and the aggregation of these cells round small 

 vessels is quite typical of the tissue. The remaining 

 elements of the tumour are very fine connective tissue 

 fibres, with very few nuclei. The fibres run in all 

 directions, except round the blood-vessels, where their 

 general course is concentric to the section of the vessel. 

 The tumours have a very distinct epithelium, continuous 

 with and similar to that lining the cysts. Its structure 

 (which is not easily made out on account of the formalin 

 fixation) is represented in fig. •'], PI. III. The cells are 

 columnar, the free edges being usually confluent, or 



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