206 REPORTS ON INVESTIGATIONS AND PROJECTS. 



This material is published in the various European languages and 

 can not all be assembled readily by any one student ; but it is now 

 more accessible than formerly, through the bibliographic work of the 

 French and Germans during the last ten years, and it is possible to 

 direct investigations where the limitations of language or time pre- 

 vent personal study. In addition to that which is published, there is 

 a large body of knowledge reserved by students, yet accessible through 

 personal conference, and this also it is hoped to reach. 



Field investigations. — Inasmuch as the available data are neither 

 free from contradictions nor complete, provision should be made for 

 field work to carry out (a) supplementary observations and (b) ex- 

 ploratory surveys. Supplementary observations may be required to 

 review controverted questions, and the most profitable method is that 

 of a field conference. 



Exploratory surveys, such as that made in China during 1903 and 

 1904, will be necessary in the less-known regions of the world, but 

 in view of the large expenditure of time and money which they may 

 occasion, their number should be limited and they should be under- 

 taken only when definite questions have been formulated and where 

 decisive results may reasonably be expected. Unknown Asia, Africa, 

 and South America will contain such districts, of which we shall 

 obtain cognizance as we develop their histories according to existing 

 knowledge. Northern Mexico presents a special problem which may 

 serve to illustrate the need of less extended field work. In the Lower 

 Cretaceous we have, in Texas and California, two distinct faunas ap- 

 parently contemporaneous. Stratigraphic evidence, so far as known, 

 suggests a connection between the then existing Atlantic and Pacific 

 waters. Why , then, are the faunas so unlike? A reconnaissance should 

 suffice to trace the line between the faunal provinces and to determine 

 its character ; and at the same time observations should be made on 

 the geology of this little-known region, which would enable us to 

 sketch the lines of continental history through the geologic ages. 

 This is a definite problem, requiring the work of a stratigrapher 

 and paleontologist in association in a district which can be narrowly 

 delimited. 



Indeterminate questions. — There are two conditions which will give 

 rise to indeterminate questions. One is the undeveloped state of the 

 science of paleogeography. Although loose generalizations based 

 on stratigraphic facts have been common, refined interpretations have 

 not been. We have yet to develop many of the criteria by which to 

 discriminate nicely between different geographic conditions that are 

 recorded in similar strata or dissimilar faunas, and thus we shall find 



