|About the Book|
Excerpt from The Opalinid Ciliate InfusoriansMost of the material used in the study of the approximately 150 new species, subspecies, and formae described were obtained from museum specimens of Anura that had lain long in alcohol, some for more thanMoreExcerpt from The Opalinid Ciliate InfusoriansMost of the material used in the study of the approximately 150 new species, subspecies, and formae described were obtained from museum specimens of Anura that had lain long in alcohol, some for more than 80 years. While much of this material was in remarkably good condition, allowing the study even of cytological details, it is readily understood that the material as a whole was far from satisfactory, both because too limited in extent and because not always well preserved. Divergent races are prevalent in many species of Protozoa, and abundant material from different sources should be used in taxonomic studies in this group. Because of the limited material, often ill preserved, the author regards his results as only tentative, constituting a preliminary review of the taxonomy of the Opalinidae and subject to extensive modification through intensive study of more favorable material.Similarly, in the chapter devoted to a discussion of the geographic distribution of the Anura and their Opalinid parasites, many of the suggestions are but tentative, pending a more thorough knowledge of geographic conditions in previous geologic periods. This chapter is written more for the sake of emphasizing a method of study of paleogeographic problems, the host-parasite method we may call it, than as a definitive contribution to paleogeographic knowledge. Concurrent evidence from the geographic distribution of both animals and their parasites, or host plants and their parasites, is so much more convincing than evidence from either the hosts or the parasites alone, that the host-parasite method of studying these problems can hardly be overemphasized. This method, rather than the particular suggestions in detail, is the thing to be emphasized in the chapter upon geographic distribution.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully- any imperfections that remain are intentionally left to preserve the state of such historical works.