Professor J. E. Marr — Address. 469 



of the group they have chosen for study. With a group like the grapto- 

 lites, for instance, the specimeus which are apparently best preserved 

 are often of little value from a morphological point of view, and frag- 

 ments frequently furnish more information than more complete specimens. 

 These fragments seldom find their way to our museums, and accordingly 

 we may examine a large suite of graptolites in those museums without 

 finding any examples showing particular structures of importance, such 

 as the sac-like bodies carried by many of these creatures. As an illustra- 

 tion of the value of work done by one who has made a special study of 

 a particular group of organisms, I may refer to the remarkable success 

 achieved by the late Mr. Norman Glass in developing the calcareous 

 supports of the brachial processes of Brachiopods. Work of this character 

 will greatly reduce the imperfection of the record from the biologists' 

 point of view. 



The importance of detailed work leads one to comment upon the general 

 methods of research which have been largely adopted in the case of the 

 stratified rocks. The principle that strata are identifiable by their 

 included organisms is the basis of modern work, as it was of that which 

 was achieved by the father of English Geology, and the identification of 

 strata in this manner has of recent years been carried out in very great 

 detail, notwithstanding the attempt on the part of some well-known 

 writers to show that correlation of strata in great detail is impossible. 

 The objection to this detailed work is mainly founded upon the fact that 

 it must take time for an organism or group of organisms to migrate from 

 one area to another, and therefore it was stated that they cannot have 

 lived contemporaneously in two remote areas. But the force of this 

 objection is practically done away with if it can be shown that the time 

 taken for migration is exceedingly short as compared with the time of 

 duration of an organism or group of organisms upon the earth, and this 

 has been shown in the only possible way — namely, by accumulating a very 

 great amount of evidence as the result of observation. The eminent 

 writers referred to above, who were not trained geologists, never properly 

 grasped the vast periods of time which must have elapsed during the 

 occurrence of the events which it is the geologist's province to study. An 

 historian would speak of events which began at noon on a certain day 

 and ended at midnight at the close of that day as contemporaneous with 

 events which commenced and ended five minutes later, and this is quite 

 on a par with what the geologist does when correlating strata. Never- 

 theless, there are many people who still view the task of correlating minute 

 subdivisions of stratified systems with one another, with a certain amount 

 of suspicion, if not with positive antipathy ; but the work must be done 

 for all that. Brilliant generalizations are attractive as well as valuable, 

 but the steady accumulation of facts is as necessary for the advancement 

 of the science as it was in the days when the Geological Society was 

 founded, and its members applied themselves " to multiply and record 

 observations, and patiently to await the result at some future period." 

 I have already suggested a resemblance between geology and cricket, and 

 I may be permitted to point out that just as in the game the free-hitter 

 wins the applause, though the patieut " stone-waller " often wins the 

 match, so, in the science, the man apt at brilliant generalizations gains 

 the approval of the general public, but the patient recorder of apparently 

 insignificant details adds matter of permanent value to the stores of our 

 knowledge. In the case of stratigraphical geology, if we were compelled 

 to be content with correlation of systems only, and were unable to ascertain 

 which of the smaller series and stages were contemporaneous, but could 

 only speak of these as " homotaxial," we should be in much the sama 

 position as the would-be antiquary who was content to consider objects 

 fashioned by the Romans as contemporaneous with those of mediaeval 



