AMERICAN GEOLOGY THE EOZOON QUESTION. 641 



In 1871 Messrs. King and Rowney read before the Royal Irish Acad- 

 emy a paper on the geological age and structure of the serpentine 

 marble of Skye, in which reference was made to structures closely 

 simulating those of the Eozoon, the rock in this case being of Liassic 

 age, and the imitative forms being the result of structural and chemical 

 changes to which such siliceous minerals as malacolite and other 

 varieties of lime magnesian pyroxenes were characteristically liable. 



This paper was followed the same year by another on the mineral 

 origin of the so-called Eozoon <-aii<i<J< n*< . which passed in review all of 

 the accumulated evidence both for and against, reiterating and empha- 

 sizing many of the statements made in previous papers. The} r held 

 that the so-called intermediate skeleton and the chamber casts of the 

 Eozoon were completely paralleled in various crystalline rocks con- 

 taining pyroxene, the chamber casts being, in fact, composed occa- 

 sionally of loganite and malacolite besides serpentine, a fact which, 

 instead of favoring the organic origin, as claimed, was to be held as 

 proof of their having been produced by mineral agencies. 



With reference to Giimbel's observations regarding the rounded 

 cylindrical or tuberculated grains of coccolite and pargasite which he 

 found in various crystalline marbles and supposed to be chamber casts, 

 they claimed to have found upon such grains crystalline planes, angles, 

 and edges, " a fact clearly proving that they were originally simple or 

 compound crystals that have undergone external decretion by chemical 

 or solvent action." 



The so-called nummulitic layer they contended had originated 

 directly from closely packed fibrous or asbestif orm serpentine, and that 

 it occurred in cracks or fissures in both the Canadian and Connemara 

 (Ireland) ophite. The fact that the two superposed asbestiform layers 

 forming the upper and under proper wall and their component aciculi 

 often passed continuously and without interruption from one chamber 

 cast to another, they argued was totally incompatible with the idea of 

 this nummuline layer having resulted from pseudopodial tubulation. 

 The canal system they found to be composed of serpentine or malaco- 

 lite, and to be completely paralleled by crystalline configurations in 

 the coccolite marble of Aker in Sweden, and in the crevices of a crystal 

 of spinel embedded in a calcite matrix from Amity, New York. 



Finally, they argued that the occurrence of the Eozoon solely in 

 crystalline or metamorphosed rocks, and never in ordinary unaltered 

 deposits, must be assumed as completely demonstrating their purely 

 mineral origin. The paper was aggressively argumentative from the 

 start and contains a very scathing review of Dawson's work, further 

 expressing a willingness to renounce the controversj 7 altogether, 

 "fully believing that Doctor Dawson can employ his time more use- 

 fully on other subjects than that of Eozoon." 



NAT MUS 1904 ±1 



