2 INTRODUCTION 



McClure, based many of his illustrations on the preparations of 

 vertebrate salivary structures contained in the Morphological Museum 

 of Princeton University, and prepared by Mr. C. F.' Silvester. 



It was therefore necessary for us to become, from the beginning, 

 familiar with the material we proposed to handle, and this involved 

 a number of years of careful study. Furthermore, we knew that 

 Carmalt was extremely anxious to enlarge his observations in certain 

 important groups, and that he proposed to control his results by the 

 study of the ontogenetic conditions in forms in which the embryos 

 could be secured. Consequently it became necessary for us to satisfy 

 both of these additional demands. We offer this statement in expla- 

 nation of the unavoidable delay which has attended the publication 

 of our colleague's work. While we have reconducted this investiga- 

 tion on the lines above defined together and with constant compari- 

 son of our respective results, one of us (Huntington) has been charged 

 chiefly with the preparation and study of the adult macroscopic 

 anatomy of the forms examined and reported, while the other (Schulte) 

 has mainly undertaken the embr3-ological investigations which we 

 considered necessary in order to complete and round out the work 

 which Carmalt had set himself to perform. We have now arrived at 

 the point where we can begin to pubUsh the results. It was our 

 purpose to primarily cover the very extensive and comphcated ground 

 of this research in a series of separate papers, published in the current 

 journals, in which subdepartments of the entire problem could be 

 handled. We proposed to continue the pubhcation of these chapters 

 until we had covered the entire problem as far as our material per- 

 mitted. When this had been accomphshed, the series of individual 

 publications, with such addenda as might have accrued in the interval, 

 were to be published in book form. Arrangements for such a publi- 

 cation had already been completed, and we intended that the resulting 

 volume should represent a tangible proof of the honor in which his 

 University holds the memory of our late colleague. Fortunateh' 

 at this time the George Crocker Research Fund enabled Columbia 

 University to provide for the publication of various researches con- 

 ducted in the several laboratories and bearing on the subject of Cancer 

 Research and alhed subjects. A portion of the investigation of 

 sahvary morphogenesis has been supported during the past two years 



