author's abstract op this paper issued 

 by the bibliographic service, februart 28 



A STUDY OF THE DEVELOPMENT OF CONNECTIVE 

 TISSUE IN THE AMPHIBIA 



GEORGE A. BAITSELL 



Osborn Zoological Laboratory, Yale University, New Haven, Conn. 



SIX FIGURES (four PLATES) 



INTRODUCTION 



The studies in which the author has been engaged for several 

 years have shown, in brief, that the plasma clot obtained from 

 frog's blood is of such a nature that, when influenced by the 

 proper factors, it is possible to radically transform its structure. 

 The reactions of the clot were studied in tissue cultures ('15) 

 and in wound healing ('16). In both these cases it was possible 

 to demonstrate clearly that the clot could be transformed into a 

 fibrous tissue which was apparently identical in structure, save 

 for the absence of connective tissue cells, with regular connective 

 tissue. In wounds made in frog skin, the experiments further 

 showed that the fibrous tissue which developed from the fibrin 

 clot functioned, at least temporarily, as a normal connective 

 tissue and there was no evidence to indicate that it would ever 

 be replaced. In the final paper of the series ('17) — in which a 

 study of the normal clotting and the transformation of the clot 

 under the influence of certain mechanical factors was studied 

 with the aid of a microscope equipped for dark field illumina- 

 tion^ — it was possible to demonstrate that the transformation of 

 the clot w^as brought about by a fusion and consolidation of the 

 fine elements of which it is composed. This process resulted in 

 the formation of long fibers which united to form wavy, fibrous 

 bundles. These bundles of fibers anastomosed with other bun- 

 dles, ramified in various directions throughout the clot and the 

 result was the formation of a fibrous material which closely 

 resembled regular connective tissue. 



447 



