SEA-FISHERIES LABORATORY. 143 



EXPLANATION OF THE PLATES. 



Plate I. Didymozoon scombri, Taschenberg. 



A single worm dissected out from a cyst, stained in borax- 

 carmine and cleared. Magnified about 17 dia. 



Plate II. Figs. 1 and 2, Didymozoon scombri. Fig. 3, 

 Benign tumour from a Halibut. 



Fig. 1. A section through a cyst containing two worms. 

 Magnified about 34 dia. 



Fig. 2. Semi-diagrammatic representation of the junction 

 of the genital ducts. The figure has been drawn 

 partly from a cleared preparation, and partly from 

 serial sections. Magnified about 140 dia. 



Fig. 3. Benign tumour from a Turbot. Section through a 

 lesion on the skin. The uninjured skin, showing 

 some scales in situ, is shown on the upper right and 

 left corners of the figure. The stippled area is the 

 locus of the tumour. Part of a small capsulated 

 tumour is seen at the lower left corner. Some large 

 bundles of muscle fibres are shown. About two- 

 thirds natural size. 



Plate III. Ovarian degeneration in a Cod. 

 Fig. 1. Longitudinal hand-section through the ovary. Bound 



the margin is the unaltered tissue of the organ ; 



centrally is the degeneration tissue. About five- 

 sevenths natural size. 

 Fig. 2. Section through the margin of the degeneration tissue. 



The stain is silver nitrate reduced by exposure to 



light. Magnified about 40 dia. 

 Fig. 3. Section through the central part of the degeneration 



mass. The stain is haematoxylin and eosin. 



Magnified about 200 dia. 



