May 8, 1908] 



SCIENCE 



749 



is a relation between points. If we had no 

 fcxed or relatively fixed datum points, to serve 

 as origins, and to enable us to establish direc- 

 tion lines, we are assured that there would be 

 no space. We should not be able to move if 

 there were nothing for us to bump against. 

 We discover a certain tree in a pathless forest 

 which no foot had trodden before. It has 

 rings of growth and a magnitude which indi- 

 cate that it must have had a history before it 

 ever came into the thought of man. But its 

 existence dates from its first discovery. It 

 was pure nothingness before. 



Let us imagine some unfortunate floater to 

 have spent his life in solitude on a raft in 

 mid-ocean. The water is smooth, the winds 

 are at rest and the sky is continually overcast 

 with a uniform layer of clouds. This we are 

 to assume will involve the conclusion that 

 latitudes and longitudes and compass direc- 

 tions do not exist. The fact that there are 

 other philosophers in Paris who have enjoyed 

 advantages which the floater has not enjoyed 

 must not be considered. 



If some of our philosophically inclined 

 brothers would spend a little more time in 

 defining the sense in which they are using 

 words, and a little less time in the futile 

 attempt to define things, the atmosphere would 

 seem clearer. The youthful floater would be 

 somewhat less at sea. 



Pkancis E. Nipher 



the satellites of maes 

 To THE Editor of Science: The letter of 

 Professor Eastman in Science, No. 695, is my 

 only excuse for taking your valuable space. 

 In consequence of Professor Eastman's letter 

 to the editor of the Transcript, there was 

 printed in the paper this explanation : " In 

 the account of the work of Professor Hall 

 presented in the Transcript at the time of his 

 death, reference was made to the discovery of 

 the satellites of Mars as ' accidental.' Al- 

 though the discovery did belong to the class 

 of the accidental because it was unpredictable, 

 still the hastily-chosen word does not describe 

 the conditions upon which the discovery was 

 based. The exact term is a little difficult to 



catch, speculative and tentative describing in 

 a way the methods by which the observations 

 were carried forward to success." 



This note prefaced half-a-column of ex- 

 tract from Professor Newcomb's " Remi- 

 niscences " on the same discovery, and to- 

 gether they formed an article that one would 

 not be expected to overlook. Being no longer 

 " live " news, the article was not published 

 till December 21. 



With reference to the companions of 

 Procyon seen at the observatory, it was simply 

 the current gossip of the astronomers of the 

 time, fifteen or twenty years ago, lingering in 

 my memory. It illustrated the splendid, 

 sterling qualities of Professor Hall better than 

 any other story that recurred to me during 

 the hurried preparation of the article. It is 

 very good of Professor Eastman to set the 

 world right in the matter, to place the dis- 

 covery of the fictitious companions where it 

 belongs and to assure us that this bit of 

 gossip has, what most gossip lacks, a founda- 

 tion. 



John Eitchie, Jr. 



SPECIAL ARTICLES 

 coincident evolution through rectigrada- 



TIONS AND FLUCTUATIONS (tHIRD PAPER') 



I PUBLISHED recently the statement of a law 

 which I believe to be fundamental in the 

 evolution of organisms, namely, " The Law 

 of the Four Inseparable Factors." ' It is ex- 

 pressed as follows: 



The life and evolution of organisms con^ 

 tinuously center around the processes which 

 we term heredity, ontogeny, environment and 

 selection; these have heen inseparable and 

 interacting from the ieginrdng; a change 

 introduced or initiated through any one of 

 these factors causes a change in all. 



' " Evolution as it Appears to the Paleontolo- 

 gist," Science, N. S., Vol. XXVI., No. 674, No- 

 vember 29, 1907, pp. 744-749. (First paper.) 



" The Four Inseparable Factors of Evolution: 

 Theory of their Distinct and Combined Action in 

 the Transformation of the Titanotheres, an Extinct 

 Family of Hoofed Animals in the Order Perisso- 

 dactyla," Science, N. S., Vol. XXVII., No. 682, 

 January 24, 1908, pp. 148-150. (Second paper.) 



