[MAVOR] PROTOZOAN PARASITES 71 
other hand the cells show no resemblance to the connective tissue cells 
adjacent to them. In the two older of the three cysts sectioned this 
layer is uneven and dis-continuous. No reference to such a layer in 
a myxosporidian cyst has been found in the literature (Auerbach :10, 
Pfeiffer ’91, ’93). 
A distinct division into ectoplasm and endoplasm is not seen in 
the myxosporidium although it is surrounded by an area devoid of 
nuclei. This absence of a distinct ectodern throws doubt on the exis- 
tance of the columnar epithelium. The writer hopes to obtain ad- 
ditional material and stages for a more detailed study of this question. 
In the outer part of the endoplasm numerous single nuclei with a 
karyosome surrounded by a clear area may be seen. Further toward 
the centre are found pansporoblasts with two, four, etc., nuclei. 
In each pansporoblast two sporoblasts are formed. 
The sporoblasts contain six nuclei, two parietal nuclei (Fig. 6, 
A, p.n.) concerned with the formation of the spore envelope, two nuclei 
(n.c., n.c.’) of the capsulogenous cells, and two nuclei in the amoebula 
(am.). One of the capsulogenous cells degenerates (n.c.’), and only 
one capsule is formed in the spore. In the ripe spore an iodinophilous 
vacuole (B, C, id.v.) is developed. 

Fig 6. Myxobolus notatus, sp.n. Spore formation. A, Sporoblast: B, con- 
tents of ripe spore; C, spore. n.c., nucleus of polar capsule cell in which capsule is 
forming; n.c.’; nucleus corresponding to second polar capsule cell which degenerates; 
p.n., two parietal nuclei; am., amaebula containing the two germ nuclei. A and B 
drawn from ‘‘wet’”’ smears stained with Delafield’s haematoxylin, C from a fresh 
preparation. x 2600. 
