142 THE SIGNS OF LIFE [LECT. 



On the second occasion after several trials with negative 

 results, I excited the cupidity of my children by the offer of 

 a reward for a blazing seaweed, and was myself rewarded by 

 their discovery of a long, narrow seaweed, called " boot laces " 

 by the fishermen chorda filuin by its museum name that 

 gave typical homodrome effects of more than 0.02 volt to both 

 directions of excitation, and therefore saved me from saying 

 that sea-plants unlike land-plants do not blaze. The difference 

 between the two kinds of vegetable is indeed very marked, but 

 it is one of degree rather than of kind, and one of the chief 

 conditions of the difference is that the former are bad and the 

 latter good conductors. Evidently, if the resistance of the 

 inactive stuff between our electrodes is so low as to afford 

 great internal shunting, an electromotive change, unless very 

 large, will not give much current to a high resistance galvano- 

 meter. 



The common animals of the sea shore limpets, anemones, 

 jelly-fish, etc. afforded little or no response to the usual test of 

 single and of tetanising induction shocks. The eyes and the 

 muscles of crabs and lobsters, the eyes and the skin of fishes 

 (whiting, sand eel), gave very well-marked effects. 



But we should not hastily conclude that the absence or 

 smallness of blaze-currents depends on conductivity alone. 

 Absence of blaze depends, also, I think, upon the relatively 

 small amount of active living electromotive stuff in the mass 

 of indifferent stuff that is its habitation. Low-class living 

 matter, pervaded and diluted by the medium in which it 

 lives, cannot be expected to exhibit any very intense sign 

 of life ; we do not expect it to blaze much. The mass of a 

 jelly-fish or of a seaweed is in chief part sea-water ; its living 

 stuff has not the power to emancipate itself from the external 

 medium, nor to create an internal medium, different and distinct 

 from the general environment. It is practically isotonic with 

 sea-water ; its freezing point, and that of sea-water, are both 

 about 2. Like sea- water, it contains over 3 per cent, of salts, 

 and its conductivity is at least fifty-fold that of land-plants. 

 This no doubt is an unfavourable condition to the production 

 as well as to the manifestation of a local alteration of potential. 



