556 MAYOR. 



ing in Delafield's haematoxylin, smears were either first destained in 

 acid alcohol or mounted directly in Canada balsam. 



For the study of attached stages, the wall of the gall bladder was 

 sectioned. Pieces of the bladder, opened in a watch glass as described 

 above, were fixed in Schaudinn's fluid, imbedded in paraffin, and cut 

 into sections from four to seven ;u in thickness. The sections were 

 stained in Giemsa's mixture or in Delafield's haematoxylin diluted as 

 for the smear preparations, or in Heidenliain's iron haematoxylin. 

 In the case of Giemsa's stain the best results were obtained by wash- 

 ing in water rapidly, for twenty seconds or so, and then destaining in a 

 mixture of acetone 95 cc. and xylol 5 cc. for eight to ten minutes. 



IV. Stages in the Life-History of C. acadiensis found in 

 the Gall Bladder. 



1. Trophic Stages. 



The earliest stage of C. acadiensis which could be recognized as such 

 in the gall bladder contained a single nucleus (PI. 1, Fig. 1). It is 

 possessed of a characteristically elongated body with a long tail. 

 Such uninucleated myxosporidia were only rarely to be found. There 

 can be no doubt, however, from their form and structure, that such 

 organisms represent a stage in the life-history of C. acadiensis. There 

 is no possibility of confusion with any of the tissue cells of the host, 

 e. g., the blood cells. The size of the nucleus, relative to that of the 

 succeeding stages, is rather large. It shows a reticular structure, in 

 which chromatin granules are embedded. 



The single nucleus of the myxosporidium divides by unequal divi- 

 sion giving rise to two nuclei differing in size and staining reaction 

 (PI. I, Figs. 2, 7). The exact nature of this division, whether mitotic 

 or amitotic has not been ascertained. It is possible that it resembles 

 the "Heteropole Teilung" described for Trypanosoma noctuae by 

 Schaudinn (: 04, p. 397, Fig. 2c). The small size of the object makes 

 the determination of this question unusually difficult. One of these 

 nuclei, usually the larger, stains faint red, or almost pink, with 

 Giemsa's stain, while the other stains a deep crimson. Both nuclei 

 show an alveolar structure of the achromatin, in the walls of which 

 relatively large chromatin granules are found. When stained with 

 Delafield's haematoxylin, these nuclei show at one end, under certain 

 conditions, a " Binnenkorper," distinguishable as a granule slightly 

 larger than the others, and surrounded by a clear area (PI. I, Fig. 4) ; 



