On a new Sporozoen from tlie vesiculiB seminales of Perichaeta. 783 



much thicker both relatively and absolutely on the stalk ; tlie membrane 

 is iu fact usually prolonged for some distauce beyond the contents of 

 the cyst ; sometimes (as in fig. 1 c) the stalk is entirely formed by 

 the membrane. 



This membrane is very distinctly laminated; it has even an ir- 

 regularly tibrous structure; the fibres are for the most part disposed 

 concentrically — but not always. The thickness of the cyst recalls that 

 of Gamocystis (Schneider, 6) and Clepsidrina (Schneider, 6) in 

 which forms however it is quite transparent; in these genera there 

 is a laminated membrane of some thickness lying within the outer layer; 

 I imagine that the two together are the equivalent of the outer membrane 

 of my Gregarine , and that a fine innermost membrane in Clepsidrina 

 and other genera which ultimately bears the sporoducts represents 

 the inner membrane of the species described in the present paper. It 

 seems to me however that the innermost of the two membranes is only 

 the cuticle of the free form (see below p. 785). 



This outer cyst membrane contains imbedded in its 

 substance numerous round bodies which I cannot but 

 regard as nuclei (fig. 4w). In transverse sections through the 

 stalk of one of the cysts these nuclei had such a regulär arrangement 

 that the membrane presented a certain resemblance to a layer of 

 columnar epithelium. I may remark that in such preparations there was 

 a row of very darkly stained dots just outside the inner membrane; 

 these are shown in the figure referred to. I regard them as the ex- 

 pression of a layer of specially thick fibrillsB (see below). With 

 regard to the nuclei of the outer cyst membrane I may quote the 

 following remarks by Waldenburg (8) about the Gregarine cysts of 

 Lumhricus. 



„Man unterscheidet gewöhnlich eine doppelte Membran : die innere 

 ist ganz der bei den Fischcysten beobachteten ähnlich, sie besteht aus 

 vielen durchsichtigen, structurlosen, sehr zarten Lamellen, welche man 

 häufig bei reifen Psorospermiencysten von einander einzeln abgelöst, 

 geblättert findet. In seltenen Fällen sieht man hier und da vereinzelte 

 Kerne in derselben. Die äussere Haut, die bei manchen Cysten fehlt, 

 sieht dem jungen Bindegewebe der Fische sehr ähnlich: man erkennt 

 bei näherer Betrachtung in einer hyalinen Grundsubstanz spindel- 

 förmige, grosskernige, durch Fortsätze mit einander communicirende 

 Zellen" etc. 



It is true that Bütschli (2, p. 536 etc.) , who is a well known 

 authority upon this group, is disinclined to accept Waldenburg'ö 



50* 



