204 CARNEGIE INSTITUTION OF WASHINGTON. 



attendants but a short time before, swimming around near the buoy to which 

 the hook was attached. This incident gives an idea of the voracity of these 

 powerful beasts. 



In studying the teleosts, I was fortunate in being able to work in conjunc- 

 tion with Dr. W. H. Longley, who is making a study of the colors of fishes. 

 With an excellent equipment of traps and nets, together with the use of dyna- 

 mite, a larger number than ever of teleosts was taken. These were carefully 

 identified and then dissected, and their external and internal morphological 

 characters were studied. Considerable data was recorded along these lines, 

 bearing on the natural history of these fishes. 



A number of forms was taken, hitherto rare in the Tortugas, some which 

 have not heretofore been reported from the waters of the United States, and 

 one or more which apparently are new species. 



Somewhat notable was the capture, on shark hooks, off the sally-port of 

 Fort Jefferson, of two huge jewfish, Promicrops gntlata. The smaller was 5| 

 feet long; the larger was 7^ feet long, 4| feet in girth, and weighed over 300 

 pounds, the limit on the spring balance used for weighing fishes. At the 

 opposite extreme for size was a little Echeneis, or shark-sucker, only 4 inches 

 long, taken from a barracuda. This is one of the smallest on record. 



Report of Researches conducted at Murray Island, Torres Strait, 

 during September and October 1913, by E. Newton Harvey. 



I. The Permeability of Cells for Acids. 



My object in joining the Great Barrier Reef expedition was to obtain a holo- 

 thurian, Chridota 'purpurea, containing a red pigment, a natural indicator for 

 acids and alkaHes. This form was collected by the Agassiz South Pacific 

 expedition of 1899 on Wailangilala Atoll in the Fiji group and has been reported 

 from various places in the South Pacific, so that the probability of its occur- 

 rence on the reefs of Torres Strait was strong. 



Unfortunately, I was unable to obtain this species, but found another holothu- 

 v\a,\\, Stycopus ananas, the "prickly fish" of the beche-de-mer industry, which 

 contains a similar dark-red indicator, and has afforded some interesting results. 

 The pigment occurs in irregular sacs in the epithelium of practically all the inter- 

 nal organs. It is especially abundant on the gonads, although the eggs and sperm 

 are colorless, so that the relation between penetrability and toxicity could not 

 be determined, as in my work with alkalies.^ On cytolysis, by chloroform- 

 saturated sea-water or fresh water or acid or alkali or heat, the pigment 

 escapes from the tissue and dissolves in sea-water, just as do other pigments 

 on cytolysis of the cell in which they are contained. It is therefore the 

 living tissues whose permeability we are studying in the experiments herein 

 recorded. 



Table 1 gives the penetration times for a strong (HCl) and a weak 

 (butyric) acid at various concentrations into living and dead (killed by 

 chloroform-saturated sea- water) testis epithelium. The acids were always 

 dissolved in artificial sea-water^ (100 NaCl + 2.2 KCl + 2CaCl2+10 MgCU 



of ^ concentration), with the exception of oxalic acid, which precipitates as Ca 



m 

 oxalate, and was therefore dissolved in ^ NaCl. The pigment changes from 



dark red in neutral to orange in acid solution. 



'Carnegie Inst. Wash. Pub. No. 183, and Journ. Exp. Zool.. Vol. 10, 507, 1911. 

 ^Quart. Journ. Microsc. See, 17, .5, 1877. 



