CKI>LIJI;AB DEGENERATION AND FOHMATION OF IMGMHNT. 107 



gave a yellovvish coloration to granules wliicli were, not 

 considerably blackened. 



(10) The Buiret test, consisting of treatment with con- 

 centrated sulphate of copper followed by concentrated potash, 

 gave no very characteristic result. The black coloration 

 {]isa})peared at once, and the granules became yellow or 

 reddish-brown ; but concenti'ated potash by itself gave a 

 similar reaction, although not so marked. 



(11) A weak solution of iodine in iodide of potassium gave 

 a faint yellowish reaction. 



(12) As a test for iron the sections were treated with 

 alcohol containing 4 per cent, sulphuric acid and 3 per cent, 

 nitric acid. After washing with pure alcohol and water, the 

 preparations were treated with a solution consisting of 1'5 per 

 cent, feri'ocyanide of potassium and 0'5 per cent, hydro- 

 chloric acid. The coloured granules exhibited no blue 

 coloration, and accordingly the test gave a negative result. 



(13) The granules had no marked affinity for eosin when 

 ap[)lied in the form of a weak aqueous solution, but they were 

 faintly tinged by the stain. 



Taking these reactions altogether, the coloured granules 

 would appear to be of a proteid nature. As already intimated, 

 the formation of pigment in hydroids is probably not to be 

 regarded as arising through the presence of bacteria or other 

 organisms, but it would seem to be due to a disturbance in 

 the metabolism of the cell, which results in the production of 

 a coloured substance in a manner resembling amyloid and 

 colloid degeneration and the calcification of cells. 



In speaking of metatnorphic processes in cells, Verworn^ 

 states : " . . . the metabolism of the cell does not merely 

 come gradually to a standstill, but is previously turned into a 

 perverse course in such a way that substances which in the 

 normal cell are either not manufactured at all, or appear 

 only as intermediate stages, are produced in ((uantity as a 

 result of the disturbed metabolism, and accumulate within 



' Verworn. Max. ' General Physiology,' English transl., London, 

 1899, pp. 330-331, 336. 



