1*11,12.] 543 



■with flint and chert deposits. In the Chalk of Antrim the only 

 deposits of beekite I have seen are associated with fossils in 

 hollow flints. 



With regard to the mode of formation, I regret to state that 

 I cannot find definite evidence from the exterior of beekised fossils 

 or from microscopic examination of sections to support Wickes' 

 ingenious theory with regard to boring by worms, etc. The 

 general trend of the evidence is against it. Again, there are 

 details which negative it ; for example, fragments of shells are 

 beekised in exactly the same fashion as whole shells, even around 

 the broken edges ; also, the process does not penetrate the shell 

 in the manner of bore-holes, but gradually, with diminishing 

 intensity to zero-point. 



The microscopic examination of slices also gave the negative 

 to Church's comparison of beekite to other radiate masses of 

 silica. The nucleus is radiated, but the surrounding whorls have 

 only a mechanical relationship to the former. 



After puzzling the matter over for some time I came to the 

 conclusion that the most feasible explanation of the phenomena 

 presented by beekite may best be explained by regarding it as a 

 chemical crystalline precipitate of chalcedony, replacing carbonate 

 of lime (aragonite more frequently than calcite) formed by osmotic 

 action in an organic medium. The organic matter of shells is very 

 small (about a half per cent.), but it is of a gelatinous colloid 

 nature. Various forms of animal gelatine have been isolated from 

 marine organisms. The presence of such matter in shells is 

 demonstrated by the action of hydrochloric acid upon them. The 

 carbonate of lime dissolves slowly and a gelatinous framework is 

 left behind. Possibly the organic matter from decomposing 

 animal matter in the circulating waters of the sediment in which 

 the beekite was deposited was a predisposing cause. Acids, such 

 as lactic acid, are formed by the decomposition of animal matter, 

 and I find that calcium lactate has an appreciable solvent action 

 on colloid silica. The latter could be furnished from microscooic 



