576 MAYOR. 



PLATE II. 



Figures 26-30. A myxosporidium containing two sporoblasts. 



Figures 26, 27. Left sporoblast; Figure 26 at a low focus, showing the 

 nucleus of a valve-forming cell (above) and the nucleus of a 

 capsulogenous cell (below); Figure 27, at a higher focus, 

 showing the nucleus of a capsulogenous cell (above), the 

 nucleus of a valve-cell (below), and the two germ-nuclei. 

 Figure 28. A diagram of the myxosporidium to show relations of sporo- 

 blasts. On the upper left side is shown a nucleus lying outside 

 the sporoblasts, one of the degenerating trophic nuclei. The 

 other nuclei are shown diagrammaticaUy as irregular circles. 

 Figures 29, .30. The right sporoblast; Figure 29, at a low focus, showing 

 the two nuclei of the capsulogenous cells; Figure 30, at a 

 higher focus, showing the two nuclei of the valve-cells at 

 opposite ends and the two germ-nuclei near the centre. 



Figures 31-34. A myxosporidium containing two sporoblasts. 



Figure 31. Left sporoblast showing (near opposite ends) the two nuclei of 

 the valve-cells, the tw^o nuclei of the capsulogenous cells and, 

 below the middle, the two deeply-staining germ-nuclei. One 

 polar capsule, drawn as a circle, showed in the preparation as 

 a deeply-stained mauve sphere, the other, higher up in the 

 figure, as a clear unstained area. 

 Figure 32. The myxosporidium showing the positions of the sporoblasts 

 and their nuclei. The small nucleus near the centre, drawn 

 in detail, lies outside the sporoblasts; it is one of the degen- 

 erating trophic nuclei. The other nuclei are drawn diagram- 

 maticaUy as irregular circles. 

 Figures 33, 34. Right sporoblast; Fig'iro 33, at a low focus, showing the 

 two germ-nuclei; Figure 34, at a higher focus, showing, at 

 the ends, the two nuclei of the valve-ceUs and, in the middle, 

 the nuclei of the capsulogenous cells. The polar capsules 

 show the same diiTerence in development as in the left sporo- 

 blast. 



Figure 35. Advanced stage in the development of a spore, showing germ- 

 nuclei far apart. 



Figure 36. Upper of the two spores shown in Figure 38, showing the nuclei 

 of the two valve cells at the ends, the polar capsules and near 

 to them the nuclei of the capsulogenous ceUs. The germ nuclei 

 lie together on the left side and are smaller and more deeply 

 stained than the others. 



Figure 37. The lower of the two spores in Figure 38. 



Figure 38. A myxosporidium showing the relative positions of the two 

 young spores. 



Figure 39. Two almost fully developed spores. The germ-nuclei are seen 

 in the right hand spore; but not in the left. 



Figure 40. A fully developed spore from the gall bladder. The capsulo- 

 genous nuclei are degenerating as are also the valve nuclei. 



