120 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 
Filament extrusion: Most certainly produced in the fresh state by 
strong sulphurie acid, iodine water, glycerin, nitric, hydrochloric, 
acetic, formic acids, alkaline hydrates, boiling water, ether, etc., espe- 
cially the first two. In alcoholic specimens, also, occasional spores 
extrude their filaments under the action of sulphuric acid or iodine. 
VIII.—DEFINITIONS. 
Anterior (and posterior): There can be no question that the longitudi- 
nal diameter is the antero-posterior axis of the body. The discrimina- 
tion of anterior from posterior is, however, in the absence of cephalization, 
impossible. I have followed custom in calling the sharper, capsular end 
“anterior,” and the opposite rounded end “ posterior.” 
Capsules: The pyriform, hollow, filament-containing bodies charac- 
teristic of the myxosporidian spore (twinned. vesicles” of Balbiani; 
““nolar capsules” of Biitschli). _‘*Capsule” is preferred to “ vesicle” on 
account of greater definiteness, and to “polar capsule,” as the situation 
implied by the latter is not constant. 
Cornua: The pointed anteriorly projecting extremities of the sporo- 
plasm. They are infero-, and supero-lateral, and infero-, and supero- 
median. (See also Surface, superior, p. 122.) 
Diameter, longitudinal: The line formed by the intersection of the 
longitudinal and vertical planes. 
Diameter, transverse: The line formed by the intersection of the 
transverse and longitudinai planes. 
Diameter, vertical: The line formed by the intersection of the verti- 
cal and transverse planes. 
Ducts: The ducts into which the capsule is drawn out anteriorly and 
which serve for the exit of the filaments. 
Ends (of the spore): The median (anterior and posterior) extremities 
in contradistinetion to the wings. 
Filaments: The filaments which lie coiled within the capsules. The 
“capsular filaments,” “spiral filaments,” and “ coiled filaments” of the 
authors. Notto be confounded with the ribbonettes. 
Host: In the usual sense; see also Seat. 
Myxoplasm: The protoplasm of the myxosporidium. 
*Myxosporidium: The amoeboid adult stage; Mutterblase, Leydig. 
Pansporoblast: see Sporoblast. 
Pericystic space: The space apparently empty (presumably fluid- 
filled) surrounding the capsules. 
Plane, longitudinal:’ Horizontal and percapsular, passing through 
both capsules and the sporoplasin, and dividing the spore into a supe- 
rior and an inferior portion. 
'For brevity and clearness these planes are defined as if rectangularly arranged 
about the center of the Myxobolus spore, the latter being supposed to be viewed ‘‘on 
the flat.” 
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