DEVELOPMENT OF A MYXOSPORIDIAN 347 



indicating that they were simply adhering to the body by means 

 of the viscid ectoplasmic covering. The formation of these 

 bud-like structures was only rarely observed and was, I be- 

 lieve, an abnormal process due to the removal of the trophozoites 

 to the slide. They were never observed until after the tropho- 

 zoites had been on the slide for some time, usually several hours. 

 No trace of bud formation has ever been observed in the pre- 

 served material, where great care was always taken to pre- 

 vent degenerative changes. Moreover the fact that these bodies 

 were so variable in size and, with few exceptions, were almost 

 certainly composed entirely of ectoplasm, would indicate that 

 they can scarcely be reproductive bodies. I interpret them as 

 being simply abnormal extrusions of the ectoplasm (possibly 

 produced by the pressure of the coverglass) analogous to the 

 lobe-like pseudopodia which often appear after the trophozoites 

 have been on the slide for several hours, and as utterly with- 

 out any significance in the life-history of the species. 



b. Preserved material. In sections of the urinary bladder tro- 

 phozoites of the large form are often seen attached to the epithe- 

 lial lining. Figure 61 represents a section through one of the 

 younger, while figure 62 is from a section through a later stage. 

 In the later stages there are always a much larger number of 

 nuclei than in the smaller, disporous forms and these nuclei are 

 of two very different types: viz., vegetative and generative. 



The vegetative nuclei are much larger than the others from 

 which they can be readily distinguished at a glance (figs. 61, 62, 

 65 to 67). They are filled with a well defined and evenly dis- 

 tributed reticulum of chromatin, and also contain at least one 

 (rarely two) large rounded nucleolus which stains deeply with 

 iron hematoxylin, but in strongly decolorized sections the in- 

 terior is considerably lighter than the peripheral portion. In 

 dried smears stained by Giemsa's method the vegetative nuclei 

 stain very differently from the generative (fig. 65). In such prep- 

 arations the chromatin of the generative nuclei take the purple 

 stain as usual while the chromatin of the vegetative nuclei stain 

 a light red and the nucleoli a light, uniform blue. The vege- 

 tative nuclei decolorize much more rapidly than the others in 



