ABSTRACTS OF PAPERS PRESENTED 106 



ANNOUNCEMENT AS TO PRESENTATION OF PAPERS 



The Chair then announced that following the request of some of the 

 members, and on account of the length of the program, the more tech- 

 nical papers dealing with vertebrate paleontology would be read in a 

 separate section later in the day and that the remainder of the morning 

 session would be devoted to papers upon general paleontology taken 

 up in the following order: 



The following paper was presented by the author from manuscript 

 and illustrated with lantern slides; 30 minutes. Discussed by A. W. 

 Grabau and Charles Schuchert. 



ALPHEUS HYATT AND HIS PRINCIPLES OF RESEARCH 

 BY ROBERT T. JACKSON 



(Abstract) 



Professor Hyatt's personality. Stages in development from the egg to the 

 adult and old age ; the most important basis for phylogenetic work. Classifi- 

 cation of stages ; a convenience in exact description. Acceleration of develop- 

 ment; an explanation of how stages come to occur. Senescence, a period in 

 life history much overlooked ; of prophetic significance. Colonial stages and 

 localized stages in development ; the natural outcome of Hyatt's work as ad- 

 vanced by his followers. Parallelism ; the taking on of similar structural 

 forms on independent lines; an aid and a danger to the phylogenist. Larval 

 adaptation; special features bnilt up as youthful adaptations and not of phy- 

 logenetic significance. 



The next paper was presented without manuscript and illustrated 

 with lantern slides ; 30 minutes. 



RESTORATION OF TERTIARY MAMMALS 

 BY WILLIAM B. SCOTT 



(Abstract) 



A drawing of a fossil animal restored in the flesh is not an entirely imag- 

 inary thing. The bones of the skeleton show clearly the points of origin and 

 insertion of the muscles which define the body contours, and by the size, shape, 

 degree of roughness, etcetera, of these points of attachment, a fairly good Idea 

 of the size of the muscles producing them may be gained. Consequently, bj 

 sketching the outlines of these muscles on a drawing of the skeleton, giving 

 them contours proportionate to the parts they have to move, a fairly accurate 

 idea of the body outlines of the fossil animal may be obtained. 



The presence, absence, length, and color of the hair on tail and body, the 

 color pattern, the shape of the ears and of I be lips and QOSe arc characters 

 which cannot be deduced from the skeleton and are largely conjectural in our 



