gQ CTENOPHORA. 



There is thus no disagreement with the results obtained by Chun from the study of specimens from 

 the Mediterranean. The slight development af the meridional vessels in the specimen figured by 

 Garbe would seem to indicate that it has been the young, not of a grown specimen, but of a young 

 in dissogony. (Comp. Taf. IX, figs. lo— ii of Chun's memoir "Die Dissogonie"). 



It is well known that this delicate species offers the greatest difficulties to preservation; 

 in most preserving fluids, and specially in alkohol and formaline, it completely dissolves, almost in 

 an explosive manner, scarcely some small pieces of skin remaining of it — strangely enough, since the 

 consistence of the jelly is rather firm, though I would not agree with Vogt & Yung (Op. cit. p. 176) 

 that it is "sehr hart und der Korper bietet fast denselben Widerstand wie Knorpel". The reason of 

 this difficulty in the preservation appears to lie in a quite remarkable impermeability of the jelly. I 

 have watched the penetration of the different preserving fluids under the microscope and found that, 

 while the skin of the animal is, of course, at once fixated, the ciliation of the pharynx and the circu- 

 lation within the gastrovascular canals continue as if nothing had happened. When then the pres- 

 erving fluid begins to penetrate into the jelly, the muscle fibres contract so violently that all the 

 inner organs break to pieces, like an explosion. On applying the mixture of Chrom-Osmic acid used 

 by Lo Bianco') for Ctenophores, one may succeed in preserving the .skin and accordingly the shape 

 of the animal rather intact, at least in small specimens, but the inner organs are, generally, destroyed 

 in the usual way. Having made this observation I thought that, if it might be possible to narcotize 

 the animal before killing it, preservation in a satisfactory state might succeed. My experiments as to 

 this gave the surprising result that the animal appeared to be nearly insensible to the different narco- 

 tizing reagents, such as ether, cocain, chloral, epsomsalt, tobacco; thus a specimen remained alive for 

 two days in a solution of tobacco so strong that the water was quite brown and strongly smelling. 

 When at last the animals could not stand the reagents any longer, they dissolved, no narcotizing 

 being obtained. When nearly giving the matter up in despair I tried to add alcohol in drops to the 

 water in which the animals were kept — and this time with excellent result. Complete narcotizing 

 was ea.sily obtained in this way, and then the inner organs remained complete, when the fixating 

 fluid (Chrom-Osmic acid) was added. Thus I succeded in getting some specimens excellently preserved 

 — until a new difficulty arose. During the time when the experiments described were carried out 

 (at the Biological Station in Trondhjem, in the month of July 191 1) the weather was ver>- cold; then 

 the temperature rose very considerably, and now in the warm weather the preservation did not succeed. 

 The narcotizing and fixation succeeded as usual, but soon after the Chrom-osmic acid had been applied, 

 the lobes of the animal swelled to deformity, the upper part of the body contemporaneously shrinking 

 to almost nothing. I cannot doubt that the reason of this must be sought for in the high temperature. 

 But, in any case, I have found, how the Bolina can be preserved very satisfactorily — in cold weather. 



It naturally follows from the great delicacy of Bolina that it must be very liable to be dam- 

 aged, when the sea is rough. In fact, I have often observed specimens which were more or less lacer- 

 ated. The same observation is made 1)\- Chun for the Lobatae upon the whole. "Sie sind vollauf 

 den Gefahren ausgesetzt, wclche Wind und Wellenschlag in Gefolge haben. Bei jedem Sturme werden 



') Salvatore Lo Bianco. The iiictliod.s employed at the Naples Zoological Station for the preservation of marine 

 .\nimals. Bull. U. S. National Museum. 39, 1899. p. 26. 



