June 23, 1903.] 



SCIENCE. 



961 



tive or a secondary character? If primitive, 

 is it in a balanced or stationary condition, or 

 is it in process of change? Secondly, is this 

 a retrogressive or a progressive character? 

 Questions to be answered certainly only by 

 the evidence afforded by ontogeny or paleon- 

 tology, and in a comparatively limited number 

 of cases by comparative anatomy. Further, 

 it may be necessary to ask : Is this a dominant 

 character, or one which has attained such im- 

 portance in evolution as to crowd out and 

 overshadow all others? 



Anatomical analysis, however, does not stop 

 here ; we must constantly be on the lookout for 

 transitional characters or characters in the 

 very act of change. These transitional or 

 evolutional characters appear at present to be 

 of four kinds: first, modifications, or such as 

 have been brought about during the life of 

 the individual without necessarily being con- 

 nected with germinal changes; second, fluc- 

 tuations, or fluctuating variations, changes of 

 degree or proportion which may be due either 

 to somatic or to germinal causes, one of the 

 most difficult problems in regard to fluctua- 

 tions being to ascertain how much is germinal 

 and how much is purely somatic; third, salta- 

 tions, which are altogether germinal, or at 

 least prenatal, in origin, including marked 

 changes of kind, the ' sports ' of Darwin and 

 Galton, the * discontinuous variations ' of 

 Bateson, and the ' mutations ' of de Vries. 

 Wide celebrity has been given to the word 

 ' mutation ' through the brilliant experiments 

 and observations of de Vries, but the original 

 significance of this term as employed by 

 Waagen and Scott was a different one, and I 

 think it probable that Waagen used it in the 

 sense of determinate variation. Fourth, recti- 

 gradation, a new term with which I propose 

 to characterize what in the year 1889 I de- 

 scribed as ' definite variations ' ; it embraces 

 changes which many writers have described as 

 * orthogenetic,' under the supposed law of 

 direct change, usually in an adaptive direc- 

 tion, which is described as Orthogenesis: these 

 probably are the ' mutations ' of Waagen. 



All the processes in column IV. are those 

 which may be observed at the time or moment 

 of observation in any organism, provided we 



have sufficient keenness of perception or suffi- 

 cient knowledge to discriminate between them. 



The elements of comparison given in column 

 v., on the other hand, relate strictly to questions 

 of origin, or to the past and the future, also to 

 questions of comparison. The fii'st broad dis- 

 tinction of comparison is between I., Homolo- 

 gous, and II., Analogous characters. In a 

 strict interpretation homologous refers only to 

 those elements which are 'homogeneous' (Lan- 

 kester), or have an actual similarity of origin 

 or ancestry. Under analogous characters there 

 is a simple distinction to be drawn between 

 the results of parallelism and of convergence, 

 terms which I maintain should be used in a 

 somewhat stricter sense than they have been 

 hitherto. Looking to the past and future, we 

 have III., the non-analogous characters and 

 the broad phenomena of divergence. Appre- 

 ciation of animal divergence, or of divergence 

 in special structures and organs, naturally be- 

 longs to the evolutionary period of anatomical 

 thought ; a period beginning with the branch- 

 ing system of Lamarck and continued in the 

 still clearer perception of divergence in the 

 writings of Darwin. I have elsewhere pro- 

 posed to employ the term ' adaptive radiation ' 

 for the general phenomenon of divergence as 

 observed in a single group, distinguishing 

 such a group in process of divergence as a 

 ' radiation,' either a ' continental radiation ' 

 where diverging on a large scale, or a ' local 

 radiation ' where diverging in a more restricted 

 environment. 



It will be observed that while these ideas 

 and terms are all evolutionary they are also 

 purely anatomical, and restricted to anatomy. 

 In a second communication the ideas and 

 terms of modern evolution will be similarly 

 treated. Henky F. Osborn". 



SOME PH.D. STATISTICS. 



We do not have to go very far back in the 

 annals of higher education in the United 

 States to discover a period when the percentage 

 of instructors at a given university who had 

 received the doctorate from the same institu- 

 tion, excluding foreign degrees, came peril- 

 ously near the maximum. During the last 

 ten or fifteen years, however, quite a change 



