390 W. LANGDON BROWN. 



acid for about twenty minutes ; on neutralisation a reducing 

 sugar and a peptone-like body were obtained. A portion of the 

 original colony^ boiled direct with sulphuric acid, yielded a 

 reducing sugar. 



Throughout the investigation the endeavour was made to 

 confirm and locate the results obtained from chemical analysis 

 in bulk by the application of micro-chemical tests. For the 

 micro-chemical detection of mucin, Waymouth Reid recom- 

 mends thionin, as used by Hoyer/ which he considers to be 

 thoroughly diagnostic. It appears probable, however, that 

 mucin gives the ruddy purple reaction with this dye in common 

 with other basophilic substances. Nevertheless this reaction 

 serves to locate the position of the mucin or hyalin which had 

 been extracted. Sections of specimens hardened in corrosive 

 sublimate were cut and stained as recommended by Reid. 

 The endoderm appeared blue, the mesogloea a ruddy purple. 

 This latter coloration was also seen in cover-slip films pre- 

 pared from the precipitated substance extracted as above. 



Hence we conclude that the mesogloea yields a substance 

 which resembles mucin — 



(i) In its solubilities. 



(ii) In its decomposition products. 



(iii) In its micro-chemical reaction. 



II. After treatment of the mesogloea with dilute acids, how- 

 ever, lime water or baryta water is capable of dissolving a 

 much larger proportion. Prolonged boiling or treatment with 

 superheated water (120° C.) will effect the same change. Lime 

 water or baryta water then leaves but a small granular 

 residue, whereas the main mass of the mesoglcea is left by 

 these reagents when repeatedly applied to the fresh material. 

 Treatment for a few days with comparatively dilute (e. g. 50 

 per cent.) alcohol greatly impairs the solubility. 



The filtrate from this lime water extract will on decomposi- 

 tion yield a reducing sugar and a proteid substance. 



This recalls the condition of affairs met with in the edible 



1 Waymouth Reid, ' Journal of Physiology,' vol. xiv. Hoyer, ' Arch. f. 

 Mikr. Auat.,' Bd. xxxvi. 



