THE ANNALS 



AND 



MAGAZINE OF NATURAL HISTORY. 



[FOURTH SERIES.] 



" per litora spargite mugcum. 



Naiades, et circiun vitreos considite fontes: 

 PoUice virgiueo teneros hie carpite floras : 

 Floribus et pictum, divje, replete canistrum. 

 At vos, o Nymphae Craterides, ite sub undas; 

 Ite, recurvato Tariata corallia trunco 

 Vellite muscosis e rupibus, et mihi conchas 

 Ferte, Dese pelagi, et pingui conchy lia succo." 



iV. Parthenii Giannettasii Eel. 1. 



No. 49. JANUARY 1872. 



I. — On the Abyssal Theory of Light, the Protozoic- Absorption 

 Theory, and the Azoic-Mud Theory, propounded in the 

 Reports of H.M.8. 'Porcupine; 1869 and 1870. By W. 

 C. M'Intosh. 



In recording the following remarks I must disclaim any in- 

 tention to cast reflections oji the scientific energy or the expe- 

 rience of marine animals of the three excellent natiu'alists 

 who were chosen by the E,oyal Society to represent British 

 zoologists in these expeditions. Such would certainly be un- 

 worthy, more especially as I had the pleasure of receiving 

 (through the intervention of Mr. Jeffreys) part of the collection 

 of Annelids (all from a depth of less than 500 fathoms) in the 

 first expedition, and the whole of the Annelida of the second. 

 Having made this necessary acknowledgment, I must also 

 admit that certain parts of the reports of my friends struck me 

 at once, on hearing the first read and on perusing the second, 

 as being slightly at variance with my own views on such 

 subjects. Some of the latter, however, are points on which 

 more than one opinion may be held ; and the following re- 

 marks *, therefore, are intended to be tentative rather than 

 dogmatical. 



* These were included for the most part in a paper read before the 

 Royal Society of Edinburgh, on the 1st of May, 18/1. 



Ann. d; Mag. N. Hist. Ser. 4. Vol. ix. 1 



