Phosphorescence of the Sea 537 



wood and of Heller (1843, 1853) on both wood and flesh. Recog- 

 nition of luminous marine dinoflagellates was a little ahead of 

 knowledge of luminous fiuigal mycelia and bacteria. Both dis- 

 coveries came at a time when fermentation and putrefaction were 

 proved to be of biological origin and helped to remove these words 

 as " explanations " of the light of the sea, of wood, and of flesh. 



Thus, the studies of many naturalists finally resulted in the gen- 

 eral acceptance of the organismal theory for all types of phospho- 

 rescence of the sea. At the present time only a person familiar with 

 the history of the subject can understand how perplexing the phe- 

 nomenon was in the early nineteenth century. Some of the greatest 

 names in biology have expressed opinions on the light of the ocean. 

 Charles Darwin (1809-1882) during the Voyage of the Beagle in 

 1831-1835, whose description of phosphorescence of the sea off 

 South America near the La Plata River has been quoted, noticed 

 that as he proceeded farther south, sea light became less prominent 

 and " this circumstance probably has a close connection with the 

 scarcity of organic beings in that part of the ocean." 



A little later, Joseph Dalton Hooker (1817-1911) , the great bota- 

 nist, and Himalayan explorer, a friend and confidant of Darwin, 

 was also experiencing his first expedition, a voyage to Antartica on 

 the " Erebus," commanded by Sir James C. Ross in 1838-1839. With 

 no plants to study. Hooker busied himself with the many marine 

 animals found at its surface. In a letter to his father, written after 

 leaving St. Helena, March 17, 1840, he wrote: ^^ 



The causes of the luminescences of the sea I refer entirely to animals 

 (living) . I never yet saw the water flash without finding sufficient cause 

 without electricity, phosphoric water, dead animal matter, or anything 

 further than living animals (generally Entomostraca Crustacea if any- 

 body asks you) . 



With this informal but definite statement of Hooker, we may 

 leave a stibject which has intrigued the curious of every nation, and 

 pass on to discoveries concerning the manner in which living or- 

 ganisms produce their light— bioluminescence. 



^^ Life and letters of Sir Joseph Dalton Hooker, by Leonard Huxley, 1: 57-58, 1918. 



