78 EXPERIMENTAL EVOLUTION LECT. 



taking note of the results. Of all my animals only 

 two were left : two Aurelia aurita, a species of medusa 

 common on the Mediterranean coast. I had originally 

 put three in the aquarium, but one had died. The three 

 I had begun with weighed 98, 82, and 57 grammes at 

 first. At the end of the fortnight the two remaining 

 famished creatures weighed but 25 and 13 grammes. 

 Assuming for accuracy's sake, and in order to prevent 

 an over-estimation of the result, that these two were 

 those which weighed originally 82 and 57 grammes, 

 we see that the loss has been at least two-thirds in 

 one case, and three-quarters in the other. 1 This loss is 

 very considerable, for, as Chossat has shown in his 

 investigations on the effects of inanition, mammals die 

 before they have lost half of their original weight. 

 When the experiment was interrupted, my Aurelia 

 were in good condition, and seemed quite inclined to 

 live longer : in fact they did live. This experiment 

 should be repeated with Beroe ovata, or some other 

 species of this genus, for I have noticed that these 

 animals rapidly lose in dimensions when in captivity 



1 Henry de Varigny, Bemerkung iiber den Gewichtsverlusl durch 

 Nahrungsmangel bei Aurelia aurita. Centralblatt fiir Physiologic, 

 12 November, 1887. Of course it must be said that in this case the 

 greater proportion of the loss of weight is due to loss of water, since 

 water is in such animals even more abundant than in higher terrestrial 

 organisms. But it must be noticed that even if the loss of weight is 

 especially due to loss of water, the latter is due to the loss of organic 

 tissues or substances with Which the water Was combined. 



