642 
DE. C. A. MAC MUNN ON THE CHEOMATOLOGY OP ACTINIAE. 
bodies ” of certain Actiniae are parasitic or rather symbiotic algae, a view which P. 
Geddes # by his remarkable experiments has endeavoured to support. 
I had made some preliminary observations t on the occurrence of a band in Actinia 
mesembryanthemum, which I believed to be due to Moseley’s Actiniochrome, but since 
I have been able to extract the pigment by means of glycerin I find that the band of 
Actiniochrome is not coincident with that seen in Actinia mesembryanthemum, as the 
former is nearer the red end of the spectrum, and the latter belongs to a colouring 
matter which, as I will shortly endeavour to show, yields certain decomposition 
products having a most remarkable resemblance to those obtainable from haemo¬ 
globin. No purpuridin is found in the last-mentioned Actinia (although supposed to 
be present by Krukenberg). 
Method of Examination. —The solid portions of Actiniae are first examined by means 
of the microspectroscope, and they are then treated with various solvents. The solid 
portions are examined in the “ compressorium,” which enables any desired thickness 
to be obtained ; they have to be well illuminated,J and for this purpose a substage 
condenser is used. The solutions are examined first with the microspectroscope, and 
then their bands measured with the large spectroscope, obtained by means of the grant 
allowed me by the Royal Society. Wave-lengths calculated by means of the micro- 
spectroscope cannot be sufficiently relied upon owing to the shortness of the spectrum, 
but owing to its superior definition the microspectroscope is indispensable, without it 
faint bands would be missed, and a comparison of a chlorophyll solution in both 
instruments shows the presence of bands with the microspectroscope which are almost 
invisible with the chemical spectroscope. 
Actinice examined. —I have examined the following Actiniae : Actinia mesembry¬ 
anthemum, Bunodes crassicornis, B. ballii, Sagartia bellis, S. dianthus, S. parasitica, 
S. viduata, S. troglodytes, and Anthea cereus. I have not been able to obtain other 
species, and my results would have been more valuable if I had had a greater 
abundance of material ; this dearth of material has been the cause of my not 
having been able to attempt the complete isolation of some of the pigments to be 
described, and of my not being able to generalise as fully as I might otherwise have 
done. I trust on these grounds too much will not be expected from these preliminary 
observations. 
* “ Further Eesearches on Animals containing Chlorophyll.” ‘Nature,’ Jan. 26, 1882, pp. 303-5. And 
“ On the Nature and Functions of the Yellow Cells of Eadiolarians and Ccelenterates.” Proc. Eoy. Soc. 
Edinburgh, vol. xi., 1881-82, pp. 377-96. Cf. also Dr. Brandt, ‘ Sitzungsbericht der Gesellschaft natur- 
forsch. Freunde zu Berlin,’ No. 9, 1881; and Professor Lankester, Quart. Journ. Micro. Soc., vol. xxii., 
pp. 229 et seq. ; vide also ‘ Nature ’ for 1882, for letters of Professors Moseley and E. P. Wright. 
t Proc. Birm. Philos. Soc., vol. iii., p. 374. 
X The source of light is an Argand gas-burner, or sometimes a “ 9-candle-power ” Swan lamp. The 
fanciful curves, recently published in Germany, obtained by means of a lieliostat and chemical spectro¬ 
scope, cannot be accurate, and show more imagination on the part of the observer than most people 
possess. The flat and other shaped summits of the bands are very remarkable. 
