660 
DR. C. A. MAC MUNN ON THE CHROMATOLOGT OF ACTINIAE. 
(in the case of Anthect cereus), is probably identical with chlorofucin. To see if this 
is the case I have figured the spectrum of chlorofucin in the natural condition in 
Fucus serratu-s and in alcoholic solution, and on comparison of these spectra with 
those of the above-mentioned Actiniae a remarkable likeness is apparent. (See 
spectra 8 and 9, Chart II.) 
As I have already shown, the conclusion of Krukenberg that the colouring 
matter of the yellow cells of Anthea cereus is identical with that of the hepato- 
chromates (= enterochlorophyll) is not borne out by this fact; viz., that in the 
case of enterochlorophyll no such change is produced by caustic alkalies as is produced 
in solutions of the colouring matter of the “yellow cells” with these reagents. 
Another very remarkable fact noticed should go to support the view of the “ yellow 
cells ” being symbiotic algae, namely, that they appear to cause a suppression of those 
pigments which in other Actiniae appear to discharge a respiratory function. In most, 
if not in all cases, this fact impressed itself strongly on my attention, and I believe 
the observation is correct. At the same time we must remember that the “ yellow 
cells ”—if they are symbiotic algae—only give oxygen up to the tissues of the animal, 
which would still require to be fixed in the tissues by a combination with something 
else, such as actiniohaematin or other pigments ; so that too much importance ought 
not to be attached to the apparent absence or presence of such pigments in the 
ectoderm, endoderm, or other parts. Their absence too ought not to be concluded 
from the mere fact that they cannot he detected in certain solutions of these 
parts, as there is no doubt that they cannot always be got into such solutions even 
when present. 
Besides these pigments of a direct respiratory use, there are others which appear to 
be of use for decorative purposes, and to this class Professor Moseley’s actiniochrome 
belongs. I always found (with one or two doubtful exceptions) that this is a pigment 
confined to the tentacles, and, as ah’ead}^ stated, it cannot be changed into anything 
capable of being oxidised and reduced ; but whether it is intended for a protective 
purpose or as a means of attracting prey, further research may decide. 
Another kind of pigment is time found in the “ eye-spot ” of Actinia mesembryan- 
themum (spectrum 9, Chart I.). It is a noteworthy fact that in the eye of Musca 
domestica f a red colouring matter occurs which gives a band covering D. It is also 
found in other insects’ eyes. Possibly, the band in Actinia mesembryanthemum denotes 
that the pigment is capable of absorbing certain rays of light, so as to enable the animal 
to distinguish light from darkness. The presence of other light-absorbing pigments, 
and their possible use in some obscure plioto-chemical processes in the bodies of 
Actiniae, ought not to be overlooked. 
The preceding observations have brought to light the following facts among others :— 
(1.) That Actinia, mesembryanthemum contains a colouring matter which can be 
* Loc. cit. 
t Cf. Krukenberg, loc. cit., he did not notice the hand referred to. 
