50 



SCIENCE 



[N. S. Vol. XLIX. No. 1254 



contracted, some completely so that tliey form 

 dense spherical masses; others are only par- 

 tially contracted. This is in accord with what 

 may be observed in the tail of the living 

 silvery tadpole. Another feature which imme- 

 diately attracts attention is the apparent ab- 

 sence of the epidermal melanophores. Upon 

 closer examination the faint outlines of a few 

 such cells may be made out. The cells con- 

 tain very few pigment granules. Whether the 

 remaining cells have migrated from the epider- 

 mis to deeper parts, as stated by Allen, or 

 whether they have become invisible from loss 

 of pigment granules could not be determined. 

 It is apparent, however, that those occasional 

 epidermal melanophores which may be identi- 

 fied contain only a small proportion of the 

 number of pigment granules to be found in 

 the normal condition. Whether the pigment 

 granules have been changed and absorbed or 

 have left the melanophore to becorae more 

 widely distributed likewise has not as yet been 

 established. 



When a silvery larva has been darkened by 

 the action of an extract of pars intermedia the 

 sub-epidermal melanophores are found to be 

 expanded, thus approximating the normal con- 

 dition. The epidermal pigment cells, however, 

 are not restored. 



It may be concluded, then, that the change 

 in color which follows hypophysectomy in the 

 frog larva is due primarily to a contraction of 

 the sub-epidermal melanophores. Only second- 

 arily is it due to a loss of pigment granules 

 from certain of the epidermal melanophores, 

 and to a possible migration or loss of other 

 epidermal melanophores. 



Wayne J. Atwell 



Department of Anatomy, 

 TJniveesity or Buffalo 



THE PALEONTOLOGICAL SOCIETY 



The Paleontological Society held its tenth an- 

 nual meeting at Baltimore, December 28, 1918, 

 meeting in affiliation with the Geological Society 

 of America. The meeting was held in the civil 

 engineering building of. Johns Hopkins Univergity, 

 with an attendance of about forty members and 

 visitors. Following the business session and the 



presentation of appreciations of the life and work 

 of four deceased members, the reading of papers 

 bearing upon the various branches of paleontology 

 and stratigraphy was commenced and continued 

 until late in the afternoon. In the evening the 

 members attended the annual dinner with the Geo- 

 logical Society of America at the Southern Hotel. 



Of special mention among the papers presented, 

 listed below, was the address of the retiring presi- 

 dent. Dr. F. H. Knowlton, on "The evolution of 

 geologic climates, ' ' in which the evidence of paleo- 

 botany was the predominant theme, and the papers 

 on the Philosophical Aspect of Paleontology and 

 the Economic Value of the Science. Important 

 stratigraphic and paleontologio results were an- 

 noimced by the members particularly regarding the 

 Coal Measures of Maryland, the Oxfordian of 

 Cuba and the Tertiary rocks of South America. 



The following papers were read: 



Paleontologio Papers 



Belation of the Solochoanites and the Ortho- 

 choanites to the Protochoanites, and the sigmfi- 

 cance of the Bactritidw: Amadeus W. Grabau. 



On the inclusion of the Pleistocenic period in the 

 Psychozoio Era: Amadeus W. Geabau. 



The philosophical aspects of paleontology : John 

 M. Clarke. 



Characters and restoration of Cope 's Sauropoda : 

 Heney Fairfield Osboen. 



Camarasaurus cmd Amphicaelias from Canyon 

 City: Heney Faiepield Osboen and Chaeles C. 



MOOK. 



Orthogenetic development of the costce in the 

 PerisphinotincB : Maejorie O'Connell. 



Discovery of the Oxfordian in %vestern Cuba: 

 Baendm Brown and Marjorie O 'Connell. 



A new Eurypterid horizon: George H. Chad- 

 wick. 



The economic value of paleontology: Balfh 

 Arnold. 



Stromatopora growth on edgeon conglomerates 

 from the Silurian: John M. Claeke. 



Stratigraphic Papers 



The age of certain plant bearing- beds and asso- 

 ciated marine formations in South America: Ed- 

 ward W. Beeey. 



The stratigraphy and correlation of the coal 

 measures of Maryland: Charles K. Swaetz, W. 

 A. Price, Jr., and Harvey Bassler. 



The typical section of the Allegheny formation: 

 Charles K. Swaetz and Harvey Basslee. 



The Eocene divisions of California: Bruce L. 

 Claek. 



Some problems of the AdirondacTc Precambrian: 

 Haeold L. Alling. 



Permo-Triassic of northwestern Arizona: Har- 

 vey W. Shimee. 



The stratigraphy and strv,cture of the Newark 

 system in Maryland and its relation to the NewarTc 

 system of eastern North America: George Edwin 



DORSEY. 



