152 PHYSIOLOGY OF THE INVERTEBRATA. 



of the neutral pigment, as can be proved. Hydrogen peroxide 

 did not affect the bands. Hydrochloric acid produced the 

 same effect as acetic acid; the bands reading: first, X 545.5 

 to X 529.5; second, X 51 1.5 to X 488. When the alcohol 

 solution is treated with stannous chloride the colour changes 

 to yellow, and two very well-marked bands appear (Fig. 29, li). 

 Dark part of the first band, X535 to X511.5; second, 

 X 496.5 to X 477. Sodium hyposulphite changed the colour to 

 yellow, but the original bands could be seen, although faint." 



Dr. MacMunn has also examined solutions of echinochrome 

 in chloroform, water, ether, carbon disulphide ; some of the 

 spectra of these solutions are given in Fig. 29. 



Echinochrome is only partially soluble in water and alcohol, 

 but is soluble in chloroform, ether, benzene, glycerol, carbon 

 disulphide, and petroleum ether. It is capable of existing 

 in two states of oxidation, therefore its function is of a 

 respiratoiy nature. Echinochrome has not been obtained in 

 the crystalline condition. 



(2) The Annelida. — The blood of many Annelids contains 

 haemoglobin ; some contain pigments allied to chlorophyll, 

 while others contain lipochromes. 



The blood of Arenicola piscatormii (one of the Polychoitci) 

 contains, besides hasmoglobin, a lipochrome or lipochromes. 

 Dr. MacMunn obtained a dark brown -green extract by treating 

 this worm with a solution of caustic potash. This solution 

 gave no bands. But he has extracted from the digestive 

 system and the integument of Arenicola certain lipochromes. 

 which have well-defined absorption spectra. 



The spectrum of the blood of Nereis DumeriUii consists of 

 a single band like that of reduced hasmoglobin. The spectrum 

 of an aqueous solution of the blood of this worm consisted of 

 two feeble bands ; " the first was like that of the first of 

 oxyhgemoglobin, but the second was rather narrower than is 

 the second blood-band. These bands read approximately : 

 the first, from X 584.5 to X 574, the second, about X 550.5 to 

 X 536, and a third one at the blue end of the green, from about 



