56 H. M. WOODCOCK. 



nucleus takes place. After liavinf^ become very finely gran- 

 ular, the chromatin is aggregated into four or five lumps or 

 pieces (c). A. well-marked spindle then makes its appearance, 

 stretching transversely or slightly obliquely across the spore. 

 Hence it is usually best seen when the spore happens to be 

 cut transversely, as in d — g. At each end of the spindle 

 is a distinct centrosome, which is, however, minute when 

 compared with the large ones described above in connection 

 wnth the multiplying nuclei. The chromatin fragments (or 

 chromosomes ? I have not been able to make out any definite 

 number) are next divided and pass along the spindle-fibres 

 to either end, where they unite again to form the daughter- 

 nuclei, the spindle eventually disappearing (/ — ;/). The 

 division of the two daughter-nuclei to form four is very 

 similar, and also takes place transversely to the length of 

 the spore ; I have not seen the division of one of these four 

 nuclei to form one of the eight sporozoite-nuclei. 



The cytoplasm possesses a marked affinity for chromatic 

 stains owing to the chromatoid granules which it contains 

 (see fig. 59 c — j inclusive). These are at first uniformly 

 distributed throughout the contents of the spore ; gradually, 

 however, they become united in a mass centrally [c, h, and j), 

 and form, together with a certain amount of cytoplasm not 

 used in sporozoite-formation, the spore-residuum or " reliquat 

 sporal.'' Fig. 60 shows a couple of typical spores at this 

 binuclear stage. I think the endo spore or inner spore 

 membrane is secreted about this time, as the cytoplasm seems 

 to fill up the funnel rather more, but at present it is very 

 delicate and difficult to make out. Later, when the four- 

 nuclear stage is reached (fig. 61), the cytoplasm has become 

 finally retracted from the funnel end, leaving the endo- 

 spore showing as an inner funnel (i./.) inside the neck of 

 the outer one (formed by the exospore), both being open to 

 the exterior. The inner funnel is closed at its base by a 

 broad, fairly thick, and deeply-staining plug or cap (c), which 

 effectually shuts oif the cytoplasm from the exterior. This is, 

 doubtless, dissolved by the digestive juices of the fresh host 



