546 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 
adult, and therefore not to be given undue weight in a systematic 
description. 
The resemblance between the pseud oscolex of these specimens and 
the scolex of Phyllobothrium lactuca was quite striking and naturally 
suggested a generic relation. This was borne out also by a decided 
resemblance between the mature proglottides of the two forms. 
When, in the summer of 1889, the opportunity of studying a fresh 
lot of these parasites was afforded the author, the discovery was speed- 
ily made that the organ at first thought to be a rostellum is in reality 
a true scolex with hooks. The relationship of the species to genera of 
the Tetrabothriidce with armed bothria, such as Calliobothrium , Acantho - 
bothrium and the like, was thus established. 
IV.— ANATOMY. 
Method of study.— No special preparation was made of the first lot 
other than to kill in weak alcohol and pass the specimens through dif- 
ferent grades of the same of increasing strength. In the other lots 
more care was taken in preparing the material for study. Specimens 
were hardened in Perenyi’s fluid, picro-sulphuric acid, osmic acid, and 
hot corrosive sublimate. The most satisfactory series of sections were 
obtained from the picro-sulphuric preparations of some small individ- 
uals stained in toto in a dilute solution of Beale’s ammonia carmine in 
glycerine. The specimens were allowed to remain in the staining fluid 
for several days. Preparations almost equally good were obtained from 
Perenyi’s fluid, followed by borax carmine (Grenacher’s). Corrosive sub- 
limate and Perenyi preparations stained with hsematoxylon (Bomer’s) 
were also quite satisfactory. The stained specimens were imbedded in 
paraflin, serial sections cut with the Ryder microtome, the sections 
fastened with Schallibaum’s fixative (clove oil and - collodion), and 
mounted permanently in Canada balsam. 
In order to make out the structure of proglottides with least per- 
plexity it is necessary to have sections made in three directions — trans- 
verse, longitudinal parallel with a lateral face, and longitudinal at right 
angles to a lateral face. 
The structure can be understood better from the sketches than from 
a written description. 
The following remarks are based on the same series of sections from 
which selections were made for the illustrations, and will probably make 
the latter more intelligible. 
Cuticle. — In the scolex the framework is made up of closely packed, 
short, parallel fibers which appear to be epithelial cells. This tissue is 
very resistant, withstanding the action of cold, and yielding very slowly 
to the action of hot, caustic potash. 
In transverse sections and in longitudinal sections made perpendic- 
ular to the face of a bothrium, the fibers are seen in their long dimensions 
