. Relics of primeval life, beginning of life in the dawn of geological time. series of the Laurentian. With respect to organic fragments not showing thestructure of Eozoon, I have not as yet been able torefer these to any definite origin. Some of themmay be simply thick portions of the shell of Eozoonwith their pores filled with calcite, so as to presenta homogeneous appearance. Others have much theappearance of fragments of such Primordial formsas ArcJicBocyathus^ now usually regarded as corals orsponges ; but after much careful search, I have thusfar been unable to say more than I could say
. Relics of primeval life, beginning of life in the dawn of geological time. series of the Laurentian. With respect to organic fragments not showing thestructure of Eozoon, I have not as yet been able torefer these to any definite origin. Some of themmay be simply thick portions of the shell of Eozoonwith their pores filled with calcite, so as to presenta homogeneous appearance. Others have much theappearance of fragments of such Primordial formsas ArcJicBocyathus^ now usually regarded as corals orsponges ; but after much careful search, I have thusfar been unable to say more than I could say in1865. It is different, however, with the round cells infil-trated with serpentine and with the silicious grainsincluded in the loganite. Fig. 53 shows such bodiesfound mixed with fragmental Eozoon and in sepa- 208 RELICS OF PRIMEVAL LIFE rate thin layers at Cote St. Pierre. In Fig. 51 Ihave shown some of the singular grains found inthe loganite occupying the chambers of Eozoonfrom Burgess, and in Fig. 54 some remarkableforms of this kind found in the limestones of Long. Fig. 54.—ArchcsospherincB from Long Lake Limestone, (Magnified.) («) Single cell, showing tubulated wall. (J>, c) Portions of same more highly mag-nified, {d) Casts decalcified, and showing casts of tubules. Lake and Wentworth. All these, I think, areessentially of the same nature, namely, chambersoriginally invested with a tubulated wall likeEozoon, and aggregated in groups, sometimes in alinear manner, sometimes spirally, like those Globi-gerinae which constitute the mass of modern deep- CONTEMPORARIES OF EOZOON 209 sea dredgings and also of the chalk. These bodiesoccur dispersed in the limestone, arranged in thinlayers parallel to the bedding or sometimes in thelarge chamber-cavities of Eozoon. They are so vari-able in size and form that it is not unlikely they maybe of different origins. The most probable of thesemay be thus stated. First, they may in some casesbe the looser superficial parts of the
Size: 1522px × 1642px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthordawsonjohnwilliamsir1, bookcentury1800, bookdecade1890
