THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 285 
of dark, longitudinal, ectoplasmic laminz separated by clear, somewhat 
reddish, apparently semifluid interlaminz. Not infrequently there exists 
a Similar clear reddish boundary layer between ectoplasm and endoplasm 
(Biitschli). 
Endoplasm consisting of colorless or yellowish myxoplasm, usually 
tinted reddish to reddish-brown (see Hematoidin below); distinguished 
from the ectoplasm by its color and by the presence of granules, globules, 
numerous small nuclei, vacuoles and inclusions (notably hematoidin 
erystals). Granules minute, arranged without order. Globules num- 
erous, irregularly scattered; in all probability fatty, being soluble in 
alcohol ;! containing hematoidin crystals. The older writers also 
inelude the nuclei under the term globules. 
Nuclei very numerous, small, with a dark surrounding membrane, 
granular contents, nucleolus and radiating fibrille (Biitschli). Pfeiffer 
remarks ? that these are to be referred back to the original single 
nucleus of the young myxosporidium. 
Vacnoles (apparently nonpulsating; indefinite as cegards number 
and position), are sometimes seen in forms with few granules. 
Hematoidin erystals: These were first observed by Lieberkiihn.® 
They were subsequently noted by Biitschli,* who rightly remarked 
that they must be derived from the biood of the host; i. e., that they 
are of extramyxosporidian origm. They occur in the fat globules, and 
are found free in the protoplasm only after solution of these globules by 
alcohol. They can be found from the smallest beginnings up to a more 
conspicuous size, the fat-globules then forming a proportionally slight 
covering for them (Biitschli). ; 
Pfeiffer > describes and figures a red blood corpuscle as included 
within the endoplasm. This he regards as the source of the hema- 
toidin crystals. He asserts that they are constantly present and that 
they occur free or within the fat-globules. He adds that if the myxo- 
sporidium has amceboidly surrounded these blood corpuscles and now 
consumes them, then in spite of the structure of the spores the Myxo- 
sporidia can no longer be regarded as Gregarines. 
Pseudopodia of 2 kinds: (1) Blunt, obtusely rounded, usually 
formed of ectoplasm alone, endoplasm taking part in formation only 
where the body as a whole forks. (2) Fine, hair-like or bristle-like, 
usually rigid, frequently branched, comparable to similar processes of 
many amcebe, frequently covering whole surface, not rarely, however, 
limited toa certain region of same (e. g., the end, as in certain amebe) ; 
1 Biitschli, Bronn’s Thier-Reich, 1882, 1, p. 594. 
2 Die Protozoen als Krankheitserreger, 1890, 1 ed., p. 44. 
3 Miiller’s Archiy., 1854, p. 350; see also next footnote. 
4 Ztschr. f. wiss. Zool., 1881, xxxv, p. 642; Bronn’s Thier-Reich, 1882, 1, p. 594. 
Biitschli credits their discovery to Lieberkiihn and Meissner. I infer from Lieber- 
kiihn’s statement, that Meissner’s results were communicated to him orally but were 
not published. 
5 Die Protozoen als Krankheitserreger, 1890, 1 ed., p. 46; ib., 1892, 2ed., pp.17, 182, 
