ANTHOZOA OF THF WOODS HOLE REGION. 
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x\mong the older students of coelenterates Johnson and Forbes made observations 
and experiments in connection with the subject, and in turn cite similar observations 
made by Ehrenberg, Spallanzani, and others, showing no less interest than has been 
common in later times. 
Macartney proved by experiments that the phenomenon might be aroused by a wide 
variety of stimuli, such as temperature, mechanical disturbance, chemical agents (as 
alcohol), electricity, etc. Forbes was able to confirm certain of these results, and also 
proved that in the phenomenon there was no evidence of electrical discharge, and further 
that no heat was evolved in connection with the emission of light. 
Allman also studied the subject in connection with hydroids. He found the phe- 
nomenon exhibited by various calyptoblastic hydroids, but not in any known gymno- 
blastea. Like other observers, he found that various physical and chemical stimuli 
were needed to evoke displays of light. He was not able to find any phosphorescent 
secretion in the hydroids, such as had been found in connection with insects and other 
phosphorescent organisms. 
Among Anthozoa its occurrence has been best known in groups of alcyonaria, 
especially in species of Pennatula, Gorgonia, etc., but not unknown in such solitary forms 
as the actinians. In the latter it has been observed chiefly in the slimy secretion of the 
ectoderm. 
Reference has already been made to the conflicting theories as to the significance 
of phosphorescence. A few words must suffice on this point. It was suggested by both 
Carpenter and Thomson that it might have some importance as a source of abyssal light, 
thus affording some means by which the inhabitants of the darkness of great depths 
might be aided in finding food, evading enemies, etc. But, on the other hand, Mosely 
has pointed out the inadequacy of such a view. Many facts seem utterly in conflict 
with the theory. For example, the light of organisms from these depths has been found 
to be more or less monochromatic, or of only two or three colors. This would suggest 
that other colors would be invisible under such light, hence incompatible with the theory. 
He concludes that colors of deep-sea forms are probably only incidental, or features 
persisting from earlier conditions when the creatures were inhabitants of shallow waters. 
And on this and similar grounds he adduces a strong argument as to the comparatively 
recent migration of many of the abyssal forms into their present habitat. 
Verrill has suggested that phosphorescence might serve as a warning to predaceous 
fishes that luminous organisms were provided with weapons of defense which it were well 
to evade. A. Agassiz has pertinently suggested that the well-known cases of Physalia, 
Cyanea, etc., and their commensals, and the habits of many fishes of feeding constantly 
in the coral and alcyonarian forests, all went to prove that “ they are not in dread of lasso- 
cells.” Among the most brilliantly phosphorescent of our local fauna are ctenophores. 
But it is well known that these are fed upon by a number of fishes. It may be safely 
assumed, therefore, that Verrill’s suggestion is utterly without significance as an 
explanation. 
