SEA-FISHERIES LABORATORY. 131 



Large spaces exist in all parts of the tumour, and 

 some of these are true lymphatic vessels. Usually they 

 contain the larger cells belonging to category (2), but 

 often they appear to be empty. Blood vessels are very 

 few and are difficult to identify. Some of the smaller 

 lymph vessels contain relatively large bodies, apparently 

 formed by the fusion of the cells mentioned, or by the 

 accumulation of some substance within them : the largest 

 of these bodies measures about 0"05 and 001 mm. along 

 its main diameters. They are loaded with brown or black 

 pigment granules. Some are represented lying freely in 

 a lymph vessel in fig. 1, PI. III. 



Sometimes a small vessel, lymphatic or blood- 

 vascular, it is difficult to say which, contains numbers of 

 the cells (2) adhering to its walls. This suggests an 

 inflammatory process. 



In a section parallel to the main diameter of the 

 tumour, it is seen that the interior of the bulbus oculi 

 also contains the same kind of tissue that is found in the 

 tumour outside. The sclerotic is incomplete in the 

 section, so that a large cavity, much bigger than that 

 necessary for the passage of the optic nerve, must be 

 present. There is no trace of the choroid layer, and only 

 the merest indication of the pigmented layer of the 

 retina. Through this cavity the foreign tissue is con- 

 tinuous. I think there is little doubt that the growth is 

 a lympho-sarcoma. It resembles strongly a small round- 

 celled sarcoma, but the connective tissue stroma is so 

 strongly developed, and the general suggestion of the 

 structure of a lymphatic gland is so striking that one 

 feels obliged to call it a lympho-sarcoma. The original 

 site of the growth was probably the choroid layer of the 

 retina. Identification of the growth as a glioma was 

 suggested by the destruction of the retina, but no traces 



