OBSERVATIONS ON VARIOUS SPOROZOA. 285 



Observations on Various Sporozoa. 



By 

 J. Jackson Clarke, M.B.LiOiid. 



With Plates 31, 32, and 33. 



Certain problems propounded in the last few years demand 

 for their solution a closer study of the intimate structure of the 

 sporozoa than has hitherto been found necessary. The varia- 

 tions of nuclear form presented by these organisms call for 

 especially close examination. For some of the higher members 

 of the group this work has been well begun by Wolters/ 

 who examined Clepsidrina blattarum, Monocystis 

 magna and agilis in Lumbricus agricola, and Klossia 

 in the kidney of snails. The description of the nuclear changes 

 in the common gregarines of the earthworm is particularly 

 complete, and since I have been able to confirm many of 

 Wolters's observations it may be of interest if they are briefly 

 reviewed here. He found in Lumbricus agricola both 

 Monocystis magna and agilis constantly present, and 

 almost to the exclusion of other species. In both, at every 

 stage, a distinct nucleus was present. In the former it was 

 relatively large and oval, in the latter of a rounded form. 

 Under compression the nuclear membrane ruptured, but the 

 contents did not escape, and when the compression was removed 

 the nucleus tended to return to its primitive form. Thus the 

 nucleoplasm appeared to be of a solid structure. In M. agilis 

 this was also observed. The nuclear membrane was found to 



^ Max Wolters, "Die Conjugation und Sporenbildung bei Gregarinen," 

 'Archiv fiir mikroskop. Anat.,' p. 99, 1891. 



