662 
SCANDINAVIAN FISHES. 
This character is accompanied, however, by several 
other peculiarities, most of which call to mind the Hemi- 
branehs. The body is scaleless, but in general completely 
covered with Ganoid-like plates, though these may 
sometimes be thin and coated with skin, so that they 
become indistinct. They are arranged in longitudinal 
and transverse rows. The number of the transverse 
rows is usually equal to that of the vertebrae, to the 
processes of which they are more or less closely united; 
and in consequence they generally form distinct seg- 
mental rings round the bod}'. In most of the Lopho- 
branchs and especially in the Pipefishes the body is 
highly elongated, like that of the Eels or the Flute- 
mouths, and the snout is produced as in the latter 
forms. The branchial arches are incomplete, consisting 
in each ease of a single cartilaginous bone; the epi- 
branchial and upper pharyngeal bones, as well as the 
hypobranchial bones, are wanting. The interclavicles 
are present, but are not externally visible. 
The organs of motion are feeble and the muscula- 
ture as a whole is not much developed; but in the motory 
muscles of the fins Rollett" has been enabled to observe 
a fact that seems calculated to possess the greatest im- 
portance for the explanation of the structure and func- 
tion of the striated muscles. Each of these muscles 
consists, as is well known, of a number of small fibres, 
corresponding to large cells, each with its envelope, a 
thin membrane, and its contents. Within the thin mem- 
brane, the sarcolemma , that confines the muscular fibre, 
we find two essentially distinct substances, the first, 
which has been named by Kuhne rhabdia, the staff - 
substance, divided into a number of cubical, parallelo- 
pipoid, virgulate, or lamellar parts, arranged beside 
each other in longitudinal or transverse rows, but in 
general at very minute intervals, which are filled by 
the second substance, the sarcoplasma, a kind of pro- 
toplasm with nuclei distributed among it. The great 
muscles of the body in the tiny Sea-horse are also of 
this structure; but Rollett has pointed out a remark- 
able difference in flic relative proportions of these two 
substances in the muscles that set the fin-rays in vibra- 
tion. Here, where the movements are too rapid for the 
eye to follow them, the sarcoplasm preponderates greatly 
over the rhabdia. Up to the present time science has 
not fully succeeded in elucidating the significance and 
a TJeber die Flossenmuskeln des Seepferdchens ( Hippocampus 
XXXII (1888), p. 233. 
co-operation of the two substances in the contraction 
of the muscles. But, as only the sarcoplasm together 
with the sarcdlemma comes in immediate contact with 
the end apparatus of the fibrillse of the motory nerves, 
we may at least conjecture both that the physiological 
significance of the two substances is different, and that 
the operation of the nervous power varies according to 
the different quantity and distribution of the two sub- 
stances in a muscular fibre. Roli.ett’s observation of 
the Sea-horse — together with several other observations, 
e. g. of the wing-muscles in insects — entitle us at 
least to the assumption that extremely rapid muscular 
motion may be promoted by the more advanced deve- 
lopment of the sarcoplasm. 
The Lophobranchs are characterized, it is true, by 
a considerable reduction of the true organs of motion; 
but one genus, Solenostomus from the Indian Ocean and 
Australia, the type of a distinct family, is fully equip- 
ped in this respect, in particular with a high anterior 
dorsal fin, a large caudal fin, and both long and broad 
ventral tins. All the other genera, which together form 
the family Syngnathidce, are destitute both of the first 
dorsal fin and of the ventral fins; the anal, caudal, and 
finally even the pectoral fins are reduced in most of 
them, and entirely disappear in some forms. When the 
caudal fin has disappeared, the tail becomes a prehensile 
organ, more or less developed, which fishes of this 
description, e. g. the well-known Sea-horses, curl round 
the branches of seaweeds or round other suitable objects, 
in order to hold themselves fast. 
All these fishes are feeble creatures, which depend 
for their protection chiefly on their resemblance to the 
surrounding objects. Our small Pipefishes closely re- 
semble the thread-algae ( ulvce ) to which they often 
attach themselves, and several Sea-horses develop foliafe 
growths sometimes of the most fantastic shapes, by 
means of which they acquire a deceptive likeness to 
the seaweed. They must seek their food among the 
weakest minute animals, for their toothless mouth is 
most like a sucking tube (cf. above, pp. 263 and 264, 
on the internal folds of the mouth in the Gobies). 
In the method of their reproduction all the Lopho- 
branchs' of which we have any information on this 
head, show the peculiarity that they carry the impreg- 
nated eggs and, until they can help themselves, the 
antiquorum') und tiler MuskelstrucUir im Allgemeinen, Arch. Mikr. Anat. 
