Febeuaey 13, 1903.] 



SCIENCE. 



275 



emanations. The conception of ' mineralizing 

 agents ' was defined, and it was shown that 

 they may be active in magma, liquids and gases 

 as well as in the reaction of gases on solids. 

 A better term is desirable for deposits formed 

 above the critical temperature of water than 

 the variously used word ' pneumatolytic' Con- 

 tact metamorphic deposits are probably di- 

 rectly caused by the action of igneous emana- 

 tions from cooling magmas, chiefly water, on 

 the surrounding rocks at a temperature above 

 the critical point. 'W. C. Mesdenhall, 



Secretary. 



CLEMSON COLLEGE SCIEXCE CLUB. 



The club held its regular monthly meeting 

 on Friday evening, January 16. The follow- 

 ing jDapers were presented and discussed: 



' The Salient Points in the Bacterial An- 

 alysis of Milk,' by Professor H. Metcalf. 

 This paper described the conventional meth- 

 ods of milk analysis and was fully illustrated 

 by experiments. 



' Prescription Milk,' to which the first paper 

 served as an introduction, was presented by 

 Professor C. O. Upton. The treatment of 

 this subject was based entirely upon the 

 speaker's experience in the "Walker-Gordon 

 Laboratory Co., where the production of milk 

 for clinical use is made a special work. 

 Ch.\s. E. Chambliss, 



Secretary. 



DlSCUSSIOy AND CORRESPOyDSyCE. 



ORTHOPLASY, ETC. 



In Science, K'ovember 21, p. 820, Professor 

 Conn treats ' Organic Selection ' as a syno- 

 nym of ' Orthoplasy,' stating that Professor 

 Baldwin has prefered the latter term. In 

 the work of Professor Baldwin reviewed (pp. 

 151, 152) we find these definitions : 



"Organic Selection: The perpetuation and 

 development of congenital variations in con- 

 sequence of individual accommodation. 



"Orthoplasy : The directive or determining 

 influence of organic selection in evolution." 



On p. 173 we read : ' The theory of evolu- 

 tion which makes general use of organic se- 

 lection is called Orthoplasy.' Orthoplasy is, 



therefore, not identical with organic selec- 

 tion, but its result. 



I will take this opportunity to suggest a 

 couple of terms : 



Directive Characters. — Those characters 

 which may be useless or harmful to the in- 

 dividual at the time of their development, 

 but lead to after-effects which are the cause of 

 survival, or are at least beneficial. Example: 

 a wandering or migratory habit might be the 

 cause of much hardship, but in the long run 

 might lead the individual (if he survived the 

 early stress) to exceptionally favorable con- 

 ditions. Human emigrants often illustrate 

 this course of events. 



Directive Individuals. — Those individuals 

 which may be useless or harmful to the race 

 during their lifetimes, but lead to after-efPects 

 which are the cause of race-survival, or are at 

 least beneficial. Example: many reformers, 

 such as the abolitionists, have by their actions 

 weakened the nation to which they belonged, 

 for the time being; but the ultimate results 

 have been highly advantageous. 



T. D. A. Cockerell. 



East Las Vegas, N. M. 



SHORTER ARTICLES. 



ON THE PRIMARY DmSION OF THE REPTILIA INTO 



TWO SUB-CLASSES, Synapsida and Diapsida. 



Since 1867 there has been a slowly progres- 

 sive movement toward the classification of the 

 reptiles by the number of arches in the tem- 

 poral region of the skull. The leaders have 

 been Giinther, in the separation of the 

 Ehyncocephalia from the Lacertilia, Cope, in 

 the union of the Archosauria and separation 

 of the Cotylosauria, Baur, Smith Woodward 

 and Broom in the suggested division of rep- 

 tiles into two groups according to the pres- 

 ence of one or two temporal arches. Broom 

 in 1901 went so far as to assign a phylogenetic 

 value to this distinction. 



Without learning until a few days ago of 

 Broom's paper* the writer had been for some 

 time studying the value of this idea. Classi- 

 fication by single characters, such as the above, 



* Through a review kindly sent the writer by 

 Franz Baron Xopsca, .Jr., and received February 

 7, 1903. 



