OBSERVATIONS ON VARIOUS SPOROZOA. 293 



of the nuclei which are preparing for subdivision show distinct 

 radiating processes, which stain deep blue with acid hsematoxy- 

 lin. Such a nucleus is shown in fig. 11 {a). The food-granules 

 in such parasites have become diminished in numbers, and in 

 some cases stain more deeply with eosin. The next stage is 

 shown in fig. 12, where the nucleus has subdivided into two 

 parts with the formation of a typical spindle. Wolters was 

 unable to observe spindle-formation in Klossia, but from the 

 identity of some of the phases of nuclear structure in C. 

 oviform e, and in Klossia as described by him, it is probable 

 that in both as also in Gregarines, spindle-formation takes 

 place. In this way two or three (fig. 1, a and a') nuclei are 

 formed. Fig. 13 shows the subdivision of a separated portion 

 of the nucleus. A typical spindle (a) is present, and the chromo- 

 somes are like those of the Gregarines, extremely small. In 

 many instances the subdivision of the nucleus appears to take 

 place more rapidly, particles of nuclear matter being detached 

 to the periphery along single achromatic filaments. The 

 appearance results in a structure almost identical with that 

 figured by Wolters in Klossia (loc. cit., pi. vii, figs. 10 and 

 11). When the peripheral nuclei are large the resulting 

 subdivisions of the parasite may be termed sporogonia, for 

 they undergo farther subdivision in the formation of sickles 

 (see fig. 8, b). When the peripheral nuclei are small, sickles 

 are formed immediately, as a comparison of figs. 14 and 15 

 suggests. Fig, 14 shows within a capsule (c) the optical sec- 

 tion of a parasite with a central nuclear mass (a) and small 

 peripheral nuclei (b). Fig. 15 shows a collection of sickles (b) 

 within a cell (a). Sometimes the peripheral arrangement of 

 chromatin takes the form of a zone of fine granules, as is shown 

 in fig. 16, a. The peculiar behaviour of chromatin in Sporozoa 

 may be illustrated by the fact that sometimes capsules are met 

 with containing sickles stained only with eosin, though in per- 

 fectly similar capsules close to them the sickles have single 

 nuclei well stained with hpematoxylin. With regard to the 

 phase of Coccidium oviforme, marked by the presence of 

 peripheral bars of chromatin which I mentioned in a previous 



VOL. 37, PART 3. — NEW SER. U 



