416 



SCIENCE. 



[N. S. Vol. XI. No. 272. 



The address of the Pi-esident, Dr. Wilder, 

 was entitled, ' Historic, ethical and practi- 

 cal considerations respecting the names and 

 numbers of the definitive encephalic seg- 

 ments.' There were presented facts and 

 arguments in favor of maintaining the cus- 

 tomary method of enumerating the seg- 

 ments of the brain beginning with the moat 

 cephalic or 'anterior,' and in favor of re- 

 taining for five of these segments the names, 

 jiroiencephalon, diencephalon, mesencephalon, 

 epencephalon and nieteneephalon, which were 

 adopted or proposed in 1867 by the editors 

 of the seventh edition of ' Quain's Anat- 

 omy.' In particular it was shown that the 

 replacement of nieteneephalon by ' myelen- 

 cephalon ' for the last (oblongatal) segment 

 aB done by Huxley and in the B. N. A., is 

 not only unjustifiable on historic and eth- 

 ical grounds, but practically objectionable 

 because it apparently involves the retention 

 of the lengthy and unrelated terms of the 

 B. N. A., viz: ' myelencephalon,' ' ventric- 

 ulus quartus,' ' tela chorioidea ventriculi 

 quarti,' ' plexus chorioideus ventriculi 

 quarti,' and ' apertura medialis ventriculi 

 quarti' (foramen Magendii), and the aban- 

 donment of the series of correlated single- 

 word terms, metencephalon, metacoelia, meta- 

 tela,metaplexus and metaporus. (The address 

 will be published in Science.) 



The following papers were read : 



Divisions of cranial bones in man and animals : 

 De. Ales Hedlicka, of New York City. 

 Five classes of divisions are described 

 and demonstrated, namely : (1) results of 

 fractures ; (2) normal, partial divisions in 

 definite locations in the bones of the em- 

 bryos and new-born ; (3) anomalous pai'tial 

 divisions consequent upon the formation of a 

 foramen in the ossifying bone ; (4) divisions 

 due to a retardation of the union of any of 

 the normal segments of the bones ; and (5) 

 anomalous divisions due to an abnormal 

 multiplicity of the centers of ossification. 



Class (2) :— Two of the most prominent and 

 constant of such divisions in man are the 

 parietal incisure of Broca, and a squamoas 

 suture situated near the middle of the occip- 

 ital border of the parietal bone (termed 'pa- 

 rietal suture ' by the author). Class (3): — 

 Eare in man, so far as the bones of the cra- 

 nial vault are concerned, but are common 

 in the human superior maxillse in connec- 

 tion with the infraorbital foramen ; they are 

 very frequent in the parietal and temporal 

 bones in mammals, particularlj' in the her- 

 bivora. Class (5) : — Occur generally in the 

 form of sutures dividing the whole bone or 

 separating one of its angles. They are lia- 

 ble to be confounded with the previous and 

 are somewhat allied to the same. These 

 divisions are well known in the human 

 parietal ; the author has the records of 

 eighteen new cases, found principally in 

 macaques ; one of the specimens presented 

 before the Association shows a bilateral di- 

 vision of the parietal bone in a chimpanzee. 

 In lower mammals these divisions are ex- 

 tremely rare. 



A fiwther contribution to the study of the tibia, 

 relative to its shapes (vide last year's Proceed- 

 ings of the Association): De. Ales Hed- 

 licka. 



An effort has been made during 1899 to 

 learn the occupations of the subjects whose 

 tibias had been examined. The returns 

 show a great diversity of occupations and 

 even of classes of occupations, and it is 

 plain that if any definite conclusions are 

 to be reached, the investigations must ex- 

 tend over at least another thousand of 

 subjects. The main indications so far are 

 as follows : Inactivity of the lower extremi- 

 ties favors the persistence of the adoles- 

 cent shape of the tibife ; considerable ac- 

 tivity in the lower limbs especially if 

 of a definite kind, favors a differentia- 

 tion in the shape of the bones. In 

 the American Indians who were always 



