ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 241 



its host. The reproductive bodies are in the form of spheres, which 

 escape from the mother organism and wander into the neighbouring 

 tissues. 



Eozoon Canadense.* — Sir J. W. Dawson gives some new facts 

 regarding Eozoon Canadense. Though the form of this body is ordinarily 

 regarded as indefinite, well-preserved specimens show that the normal 

 shape of young and isolated examples is a broadly turbinate, funnel- 

 shaped, or top-shaped form, with sometimes a depression on the upper 

 surface. Other forms are rounded or dome-shaped masses. In sections 

 more or less cylindrical depressions or tubes may be seen. If Eozoon 

 was an organism growing on the sea-bottom, it would be liable to be 

 broken up, and in this condition to constitute a calcareous sand or 

 gravel ; examination of Laurentian limestones frequently reveals the 

 presence of Eozoon. Cryptozoum, whatever be its zoological relations, 

 is found in Cambrian rocks under the same conditions as Eozoon in the 

 Laurentian. The mistakes made by some lithologists are due to the 

 remarkable imitative forms of gneiss, laminated limestone with serpen- 

 tine, and various other laminated or banded materials which are often 

 found in collections or specimens of Eozoon. As to these, Sir J. W. 

 Dawson promises further details. In a postscript the objections to the 

 suggestion of Julien and others that eozoonal structure may be due to 

 the alternation of mineral layers formed in the passage-beds between 

 concretions and their inclosing mass are summarized. 



* Geol. Mag., v. (1888) pp. 49-54 (1 pi.). Cf. also Rep. Brit. Assoc. Adv. Sci„ 

 1887 (1888) p. 702. 



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