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 liave found the largest cysts to contain only Gluge's structureless granules. In 

 any case these facts are not yet sufficient to establish a developmental series. 



In recapitulating and summarizing his results (the order of sucli 

 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 Gasierosteus 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 Gasierosteus for 

 those cysts, I refouud them first in March of this year in great numbers. Of the 

 cysts liscovered by Gluge I am not at present able to give any explanation, other 

 than that they are entirely difterent from the ones now to be discussed. 

 Page ii55] 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 

 i to 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 a knife. 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 O'OOl'". 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 larger fatty graniile l.ying 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 0-008'", of the 

 nucleus lEern^ 0*005"', of the fine granules about 0-0007'". In the largest, grauules 

 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 Avas 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 diflerent relrangibility, 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 



