4f;6 



THE DEl'TUS OF THE SEA. 



[on.-i 



a Fasus from 1,207 fathoms Avas similarly provided. 

 The presence of organs of sight at these great depths 

 leaves little room to doubt that light must reaeh eveu 

 these abysses from some soiirce. Prom many con- 

 siderations it can scarcely be sun-light. I have 

 already thrown out the suggestion that the Avhole 

 of the light beyond a certain depth might be due 

 to phosphorescence, which is certainly very general, 

 particularly among the larvas and young of deep- 

 sea animals ; but the question is one of extreme 

 interest and difficulty, and will require careful in- 

 vestigation. 



■i;ii,\l I m: HA,Mi,i:i ui \ irn 



