In the future it is hoped that an arrayof 50 photomultipliers may be used,with each recording a part of thespectra. This will drastically reducethe observation time. From the obser-vations and theoretical interpretation ofwhite dwarf stars, one can obtain vitalinformation regarding the mass, density,surface temperature, and eventually,evolution track. Most white dwarf starshave a surface gravity of 10' cm/sec2.From this and the theoretical radius-mass relation, one can conclude thatthe average mass is 0.5 solar massand the radius about 1/70 of the radiusof the sun. Although it is not possibleto determine the mean molecular weightaccurately at present, results indicatethis may be achieved with better obser-vational equipment and with bettermodel atmospheres for white dwarfs.HONG-YEE CHIU, Program Arranger

Growth and Development of theFace, Teeth, and Jaws

The growth and development of theface, teeth, and jaws and future re-search in this field were the subjectsof a four-session symposium sponsoredjointly by the Dentistry Section (Nd)and the Section on Anthropology (H)at the annual meeting of the AAAS inCleveland, Ohio (26-27 December).

Paul E. Boyle (chairman of SectionNd) opened the sessions and wel-comed the audience. Albert A. Dahl-berg (University of Chicago) empha-sized the variations in types and sizesof dento-facial structures and notedthe processes involved in evolutionarychange. In a discussion on normalvariations in dento-facial growth,Coenraad Moorrees (Forsyth DentalCenter) stressed the importance ofdirecting future research toward a bet-ter understanding of factors that con-tribute to individual differences (sourceof variants).More emphasis than ever before was

placed on the extent of genetical in-volvement in dental facial growth, andthe discussions to a degree were farremoved from conventional, historicalanalyses. Harold 0. Goodman (Bow-man Gray School of Medicine, Win-ston-Salem) carefully scrutinized thepresent literature and indicated thatmuch past information on the inheri-tance of dental and facial parameters,and in particular, modes of inheritanceof specific dental defects need moreadequate testing, and in many cases,

21 FEBRUARY 1964

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confirmation. Uwe Stave (Fels Re-search Institute) detailed the interac-tion of genetic and environmental fac-tors in dental and facial malformation,and noted the extent to which suscepti-bilities to environmental insults were,in part, genetically determined. Devel-opmental defects with associated facialdisturbances were discussed by Fred-eric N. Silverman (Children's HospitalResearch Foundation, Cincinnati). Healso presented an illustrated series ofcases, including arrhinencephaly andtrigonocephaly.

Discussions by M. Michael Cohenand R. A. Winer (Tufts), Tatsuo Fu-kahara (University of Chicago andTokyo University School of Dentistry),and Robert J. Gorlin (University ofMinnesota) indicated the increasingevidence for dental and facial defectsin chromosomal abberations, deletions,reduplications, and translocations. Inparticular, Gorlin traced changes inpalatal height and arch width from the(naploid) XO (Turner's syndrome),the XX, the XXX, the XXY, theXXXY, and so forth. Reacting as if atiming mechanism were involved, pal-atal height and arch breadth alter withthe amount of X chromosomal materialheld in common. Fukahara noted theextent to which siblings'of children af-flicted with cleft palate were character-ized by minor cephalo-facial disturb-ances; this fact is clearly suggestive ofthe carrier state and was originallysuggested by Neel (Volume 1, Number1, American Journal of Human Genet-ics). In this connection also, Daris R.Swindler and Harriet Ann McCoy(Medical College of South Carolina,Charleston) demonstrated that thetype of polymorphism in tooth se-quence existing in colony-reared rhesusmonkeys was the same as that foundin family studies of normal childrenfrom southwestern Ohio. From thisand other observations it was suggestedthat primates as a group (specific pri-mate species and sub-species) possessmany genes in common that affect den-tal and facial development.

Discussions in the final session ex-tended many of the ideas presented inprevious sessions and also suggestednew lines and directions of research.Panel members (Richard C. Greulich,University of California; Jerry D. Nis-wander, National Institute of DentalResearch; Wilton M. Krogman, Uni-versity of Pennsylvania; Edward E.Hunt, Jr., Harvard University; andRobert E. Moyers, University of Mich-

SCIENCE, VOL. 143

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igan) generally agreed that there mustbe a critical reexamination of old andprevailing concepts; exploration of newconcepts of control mechanisms ofgrowth, with particular regard to as-pects of canalization or buffering ofgrowth; additional studies at the molec-ular level. Also emphasized was thatadvances in knowledge of malforma-tions and normal growth, while de-pendent upon a better understandingof molecular genetics, can be furtheredby explaining the complicated interac-tions between environmental agentsand associated complex, multiple, he-reditary factors. In addition, there isgreat need for further defining the fac-tors with the capacity for controllingcell proliferation and differentiation.

Publication of the proceedings ofthis conference will be aided by agrant from the National Institutes ofDental Health and will be distributedas a special supplement to the Journalof Dental Research; it will include con-tributions from E. Holly Broadbent,Carl J. Witkop, and Seymour Kresh-over. The arrangers for the overallprogram were Stanley M. Garn andSholom Pearlman (American DentalAssociation) and the sponsors includedthe AAAS section on Anthropology(H), American Dental Association, In-ternational Association for Dental Re-search (North American Division),and the American College of Dentists.

SEYMOUR J. KRESHOVER, SecretarySTANLEY M. GARN, Programn Arranger

Science Research Planning:Instruments and Equipment Use

The programs of the conference werejointly sponsored by the Office of Eco-nomic and Statistical Studies of the Na-tional Science Foundation and by theIndustrial Science Section (P). Themorning session was concerned with therole of instrumentation and equipmentuse in science research program plan-ning; the afternoon session was morebroadly oriented to the planning andmanagement of science research pro-orams.The introductory paper by Zola

Bronson (National Science Founda-tion) addressed itself to two major as-pects of the role of instruments andequipment use in science research pro-gram planning-development of a pre-liminary estimate of present R&D dol-lar expenditures for instrumentation in21 FEBRUARY 1964

Only two minutes! That's all it takes from the time you turn iton in the morning to the time you're ready to run tests on samples.That's with the transistor-regulated Spectronic 20; the standard Spec-tronic 20 is ready to run in less than 15 minutes. You might spend oneof those minutes reviewing some of the other special things about it.Like stability; and extended range, from 340mu to 950m1u; and the factthat you can select any wavelength in that entire range at the turn ofa dial. Versatile? No other colorimeter, at any price, can come close.All right, minute's up. Shall we get to work?

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Growth and Development of the Face, Teeth, and JawsSeymour J. Kreshover and Stanley M. Garn

DOI: 10.1126/science.143.3608.869 (3608), 869-871.143Science 

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is a registered trademark of AAAS.ScienceScience, 1200 New York Avenue NW, Washington, DC 20005. The title (print ISSN 0036-8075; online ISSN 1095-9203) is published by the American Association for the Advancement ofScience

No claim to original U.S. Government Works.Copyright © 1964 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science.

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