HEAET-BODY, ETC., OF CEETATN POLYCHiETA. 285 



geneous granule of a clear red colour, about a quarter of the 

 diameter of the cell ; then there are usually two emerald-green 

 globules, each of which is somewhat less than half the size of 

 the red granule; and finally, there are numbers of still smaller 

 granulations, deep brown in colour, which are usually con- 

 centrated at the poles of the cell, as seen in isolated cells of 

 macerated and teased tissue (fig. 26). The nuclei are large, 

 and are placed towards the inside or lumen of the organ, 

 whilst the large granulations are towards the outside (fig. 23). 



The green globules look like oil droplets, but, like the red 

 and brown granules, are insoluble in ether. They blacken 

 somewhat with osmic acid ; and with acetic both they and the 

 red granules lose their colour. With cold 50 per cent, hydro- 

 chloric acid the red pigment is dissolved and stains the cells, 

 and the brown granules at a certain focus look purple. The 

 latter are not dissolved even on boiling with the dilute nor on 

 standing in the strong acid in the cold, though they disappear 

 on heating. The residue of a solution in nitric acid fails to 

 give the murexide reaction. Cold caustic soda solution re- 

 moves the red and green bodies, but only causes the brown to 

 swell and turn a paler shade. On boiling, however, they too 

 dissolve, but a small residue of insoluble bodies remains, some- 

 what resembling the chitinous bodies of Audouinia.^ In 

 some of these, which had been boiled on the slide with alco- 

 holic potash, the double salt of chloride and iodide of lime 

 produced a yellow, and in some cases a violet tinge (Dr. Mayer). 



Fat was not found in the heart-body. 



Iron is shown by the Prussian blue reaction in some of the 

 granules. The ammonium sulphide test occurs only on 

 heating, but after six hours at a temperature of 60° C. tissue 

 treated with this reagent is dotted over with clearly defined 

 greenish-black patches, which I believe to represent the red 

 granulations. After the action of Bunge's fluid for an hour at 

 60° C, followed by nitric-alcohol, ammonium sulphide fails to 

 produce any coloration, so that the iron must be in such 



' These are not noticeable in sections, but I have found pale-staining bodies 

 in the lumen which may represent them. 



VOL. 41, PART 2. NEW SERIES. U 



