OPPONENTS AND OBJECTIONS. 183 



directing attention to these illustrations, is to show 

 the nature of the misapprehensions which may occur 

 in examining specimens of this kind, and. at the same 

 time the certainty which may be attained when proper 

 precautions are taken. I may add that such struc- 

 tures as those referred to are best seen in ex- 

 tremely thin slices, and that the observer must not 

 expect that every specimen will exhibit them equally 

 well. It is only by preparing and examining many 

 specimens that the best results can be obtained. It 

 often happens that one specimen is required to show 

 well one part of the structures, and a different one 

 to show another ; and previous to actual trial, it is 

 not easy to say which portion of the structures any 

 particular fragment will show most clearly. This 

 renders it somewhat difficult to supply one's friends 

 with specimens. Eeally good slices can be prepared 

 only from the best material and by skilled manipu- 

 lators ; imperfect slices may only mislead ; and rough 

 specimens may not be properly prepared by persons 

 unaccustomed to the work, or if so prepared may 

 not turn out satisfactory, or may not be skilfully 

 examined. These difficulties, however, Eozoon shares 

 with other specimens in micro-geology, and I have 

 experienced similar disappointments in the case of 

 fossil wood. 



In conclusion of this part of the subject, and 

 referring to the notes appended to this chapter for 

 further details; I would express the hope that those 

 who have hitherto opposed the interpretation of Eozoon 



