IN THE ANIMAL KINGDOM. 



An elementary analysis of echinochrome was made by Griffiths (Compt. 

 rend. soc. biol, 1892, cxiv, 419, 669, 738). This substance he obtained from 

 Echinus esculentus, Strongylocentrotus lividus, Echinus sphcera, etc. He 

 showed its very close relationship to hemoglobin, and he gives the follow- 

 ing as the molecular formula: 



Griffiths also analyzed hemerythrin, and gives to it the formula 



Robert (Archiv f. ges. Physiologic, 1903, xcvin, 411) states that the 

 hemerythrin from the corpuscles of Sipunculus nudus contains the iron, 

 unlike in hemoglobin, in loose combination. He failed to obtain hemin 

 crystals, hemochromogen, or hematoporphyrin by means of the ordinary 

 processes. H 2 2 was decomposed by it, but he did not find any blue color- 

 ation with guaiac. 



The chlorocruorins, which from the molecular formula of Griffiths are 

 more closely related to hemoglobin than either echinochrome or hemerythrin, 

 have been studied by a number of investigators. The green coloration 

 of the blood of certain annelids was first pointed out by Milne-Edwards 

 (Ann. des Sciences Natur., 1838, x, 190) and later by Quatrefages (quoted 

 by Ray Lankester, loc. cit.) in Siphonostoma. Krukenberg (Vergleich. 

 physiol. Studien, 1 Rh., 3 Abth., 1882, 87) noted this green pigment in 

 Spirographis and Branchiomma. Ray Lankester (loc. cit.} studied the chloro- 

 cruorins of Siphonostomum and Sabella. He found that, like hemoglobin 

 and oxyhemoglobin, there exist chlorocruorin and oxychlorocruorin, which 

 show different absorption spectra; and he states his belief that hemoglobin 

 and chlorocruorin have a common base in a so-called cyansulphaem (an 

 undetermined body), or perhaps in Stokes's reduced hematin. 



MacMunn (loc. cit.} subsequently studied the optical properties of oxy- 

 cruorin and reduced cruorin. The green fluid of Sabella, he found, had a 

 reddish tinge with reflected gaslight, and in most cases it was green with 

 transmitted daylight and reddish with transmitted gaslight. On dilution 

 with water the solution gave two bands: the first between C and D from 

 a 618 to a 593 ; and second between D and E from 2, 576 to ^ 554.5. On then 

 adding ammonium sulphide the first of these extended from X 625 to X 596, 

 but it and also the second bands were very faint. "If now caustic soda 

 were added to this solution a dark band was seen covering D, which recalls 

 to mind the band of alkaline hematin, and this band extended from % 595 

 to X 576." 



He also studied the blood of Serpula contortuplicata, which he found 

 presents some resemblance to that of the Sabella. An aqueous solution 

 obtained from 9 serpulse was of a reddish-yellow color by gaslight and 

 yellow by daylight. The band before D was from /I 620.5 to /t 593, the 

 second about A 583.5 to A 572, the third uncertain (about a 551 to A 532). 

 After adding sulphide of ammonium the only band seen with certainty 

 was that before D, which seemed slightly nearer the violet. 



