Mr. P. H . Gosse on the Chylaqueous Fluid in the Actinoida. 1 73 



testing its correctness ; and I now send you the following results 

 of my experiments. 



I should premise, that in each of the following examples the 

 fluid was taken from the animal out of ivater ; either, as in the 

 case of A. mesembryanthemum, one that had stationed itself at 

 the surface, so that its body was partially exposed and dry ; or 

 one that became so exposed by a slight tilting of the vessel ; or 

 one that was taken out of the water. In all cases, the surface 

 was carefully wiped with a soft linen cloth, to remove the ex- 

 ternal sea-water. The fluid was then obtained by making with 

 a lancet an incision through the integuments, and by taking up 

 the flowing liquid by means of a pipette, which, in some cases, 

 needed to be inserted into the wound, before capillary attraction 

 would induce the liquor vitalis to flow up. 



The drop thus obtained was then deposited in an aquatic 

 stage-cell, and flattened by means of the thin-glass cover. It 

 was then submitted to a power of 600 linear under one of 

 PowelPs microscopes, the measurements being made with one 

 of Jackson's eye-piece mici-ometers. Afterwards its albuminous 

 character was tested by the addition of a minute quantity of 

 nitric acid. The pipette was scrupulously cleansed, between the 

 experiments, by repeated injections of fresh water, and all the 

 instruments used were similarly washed and wiped. 



Actinia vieseuibryanthemum. — The fluid was rather thinly 

 studded with organic corpuscles ; nearly circular in form, smooth 

 and well deflned in outline, delicately granulose in texture, and 

 pale yellow in colour. They varied in dimensions from "0002 

 inch to -0007 in diameter; but the great majority averaged 

 about 'OOOS. A drop of the same fluid spread on a slip of glass 

 was perfectly hyaline ; but, on nitric acid being added to it, it 

 became distinctly milky. 



Anthea cereus. — Corpuscles moderately numerous; mostly 

 circular, rarely oblong, and drop-shaped ; of a clear pale yellow 

 hue ; granulose ; dimensions from '0001 to "0003, average 

 •0002 inch. With nitric acid, milkiness barely perceptible. 



Sayartia parasitica. — Similar corpuscles, but far fewer and 

 smaller; dimensions varying from '0001 to '0003, the majority 

 about 'OOOlo. With nitric acid, the milkiness was very slight, 

 but perceptible. 



Sag. nivea. — Corpuscles abundant, clear pale yellow ; not 

 apparently granular ; more highly refractive than the surround- 

 ing fluid*; irregular in shape and size, but for the most part 

 ovate or elliptical, averaging about '0008 inch in longer dia- 



* This character is not intended to be distinctive of this species ; I 

 believe it marked the corpuscles in all cases ; but it was in this example 

 that I first tested it hy focusing. 



