184 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 
that described by Gluge; I was not able to discover anything definite therein. So 
far I have found the largest cysts to contain only Gluge’s structureless granules. In 
any case these facts are not yet sufficient to establish a developmeutal series. 
In recapitulating and summarizing his results (the order of such 
summary and the place therein of the following extract showing that it 
refers to and is intended as the summary of the preceding quotation) 
Lieberkiihn says: 
In the skin of Gasterosteus occur, besides the grain-containing cysts discovered by 
Gluge, also such as contain psorosperms of peculiar species. 
In a subsequent article Lieberkiihn again discusses these problem- 
atical organisms. He says: 
[Page 354] As regards the psorosperm-like bodies of the stickleback, to which I 
have already, in my preceding =rticle, devoted some words, I have now 
succeeded in making the requisite observations preliminary to a knowledge 
of their developmental history. After I had, in the course of the preceding 
autumn and winter, examined in vain several thousand specimens of Gasterosteus for 
those cysts, | refound them first in March of this year in great numbers. Of the 
cysts discovered by Gluge Iam not at present able to give any explanation, other 
than that they are entirely different from the ones now to be discussed. 
Page 355] The latter I have frequently found, to the number of 30 or more, dis- 
tributed over the skin, the fins, and the cornea; some had bored through 
the fins and floated with both ends free in the water; others lay closely appressed to 
the skin for their whole length; others again were detached on one side. Individual 
fishes had their tail-ends so beset that scarcely anything of the scales could be seen. 
Their usual form is cylindrical; rarely they are ellipsoidal or spherical. They strike 
the eye with the first glance at the fish. The length of the rod-shaped is from 
ito 1 line; the greatest diameter of a cross-section about one-fifth line or more. 
The membrane of the cyst is plainly visible, and one can easily obtain it for exami- 
nation by removing it by means of aknife. I could not discover any structure in it. 
The contents present great variations. In some I found nothing but an albuminous 
substance, in which fat-like granules were suspended in great numbers; these were 
globular and measured 0:001’". If one moves them to and fro under the cover glass 
for some time many of them flow together to large oily drops. Other cysts contain 
partly these, partly much smaller but apparently similar granules. In still other 
cysts the granules of the smaller variety were united by a mucous substance into 
globules; many of these were distinguished by a much Jarger fatty granule lying in 
the middle between the smaller ones, and which often had an irregular form. 
In still others this was seen to be 2 or 3 times as large, and in these cases the small 
granules were usually entirely absent; furthermore, the whole psorosperm had a 
proportionately greater size. The diameter of such a body was 0:0038’’, of the 
nucleus [Kern] 0:005', of the fine granules about 0:0007'’.. In the largest, granules 
began to appear anew, and it sometimes seemed as though they separated them- 
selves from the nucleus. The expression nucleus has here no further significance 
than that which it receives through the investigation. Sometimes I was able to 
observe the same isolated, when for some unknown reason the surrounding mem- 
brane became ruptured and expressed its contents, It showed nothing but what 
one could see through the surrounding membrane. When the psorosperm dries on 
the cover glass it acquires an entirely different retrangibility, the sharp contour 
disappearing and not reappearing when water is added. In some cases I found also 
in fresh cysts such nuclei of feebler refrangibility within the smaller psorosperms. 
They vary greatly in size; were often simultaneously provided with granules, such 
being, however, often absent. In order to learn the further alterations of the cyst 
contents, I kept a number of cyst-bearing fish alive for some weeks in my room. 
Apparently the thin cysts increased in circumference, and then contained only the 
