February io, 1893. J 



SCIENCE. 



Notes on Several Special Transformations. 



While reciprocatina; and subtracting from unity both belong to 

 the periodic transformations whose period is two, yet the two 

 combined lead to a transformation whose period is six. It is of 

 special interest to obser^fe that the six values thus obtained are 

 the SIX related values of an anharmonic ratio. They are the fol- 

 lowing:— 



1 a - 1 a 1 1 _a 



'a' a a — r 1 - a 



This furnishes a convenient means of remembering these im- 

 portant values. 



In the special case of homographic transformations, when 



_ay — fflj 



~ aaV — a 

 we easily see that is expressed in the same form with respect to 

 .te as X is with respect to y. That is 



has been distributed to the various museums, if I am not mis- 

 taken. 



It will thus be seen that "the total amount of material per- 

 taining to Rytina found in the museums oi the world " is consid- 

 erably larger than the three skeletons and two ribs mentioned by 

 Dr. Evermann. Leonhard Stejnegeb, 



tr. S. National Museum, Smlttasoulaa Institution, ■Washington, B.C., Feb. 7. 



a^X — a 

 When X and y are reals the locus of this equation is symmetri- 

 t'iil with respect to the bisector of the angle between the x and y 

 axes. Geo. A. Miller. 



Eureka C\ liege, Jan. 26. 



Skeletons of Steller's Sea-Cow Preserved in the Various 

 Museums. 



In the last number of Science (Feb. 3, 1893, p. 56) Dr. Barton 

 W. Evermann has an interesting note on the "Skeleton of Stel- 

 ler's Sea-Cow," which he was fortunate enough to purchase for 

 the National Museum during his stay at Bering Island, 1892. 

 The article is slightly erroneous where he enumerates the mate- 

 rial in the museums previous to his visit to the island, as many 

 more skeletons and parts of skeletons are pi'eserved than he 

 thinks. 



He says: "This[i.e., the skeleton in the U. S. National Museum, 

 made up from bones brought home by me], together with the two 

 skeletons at St. Petersburg and Helsingfots, and the two ribs in 

 the British Museum, consticute the total amount of material per- 

 taining to Rytina found in the museums of the world at the time 

 of my visit to Bering Island." 



Let me add to this that there is a fairly good skeleton in the 

 museum of the Swedish Academy of Sciences at Stockholm, 

 brought home by Nordenskiold, and figured by him in his famous 

 account of the "Vega'" expedition. Another "nearly perfect" 

 skeleton is in the British Museum, described and 6gured by Henry 

 Woodward in the Quarterly Journal of the Geological Society 

 (London, August, 1885, pp. 457-472). A third skeleton of Rytina 

 gigas, and, in some respects at least, the best one, is in the 

 museum of the Academy of Sciences in San Francisco, where it 

 was mounted during the early part of 1893. This skeleton was 

 formerly part of the museum belonging to the Alaska Commercial 

 Company, but was afterwards presented to the Academy. As I 

 aaid, this skeleton is in some respects superior to any one thus far 

 found, although the cranium mounted with it belongs to another 

 specimen. It was found on Bering Island during the winter of 

 1881-82, and as the cranium was not in as good condition as the 

 rest of the skeleton a better one was substituted. I acquired the 

 original, which is among the many crania which I collected for 

 the National Museum. 



These are the three entire skeletons of which I have any record, 

 but there are undoubtedly several others in various museums. If 

 I am not mistaken, St. Petersburg has acquired additional mate- 

 rial (recently the Museum there offered a skull in exchange), and 

 so have the museums in Moskva, Odessa, and, above others, 

 Warshaw, to which city Dybowski sent most of the material col- 

 lected by him. It is also reasonable to suppose that he reserved 

 some for the universsty in Lemberg. 



I myself collected about 20 crania for the National Museum be- 

 sides quite a number of isolated bones in addition to those which 

 were used in the "made-up" skeleton. Some of this material 



' Unconscious Cerebration." 



Some very puzzling psychological phenomena may be explained 

 in simple ways by happening upon the correct point of view. 



Numerous theories have been afloat to account for recollections 

 of what had apparently never been seen before. For example, a 

 friend of mine came across a scene in the Yellowstone, on his first 

 visit to that region, and was astounded at the familiarity of every 

 detail upon that occasion. 



Knowing that he was addicted to fits of abstraction, I suggested 

 that while preoccupied he had unconsciously mentally registered 

 his surroundings and soon thereafter, without being aware of so 

 doing, compared a conscious impression with an unconscious 

 one. 



A convincing illustration in common experience is afforded all 

 of us when we are carefully reading a book and suddenly become 

 aware of having turned a page or even several pages while think- 

 ing of something else all the time, and when we turn back aud 

 begin again are surprised to find that every word is familiar to us, 

 though the reading over again was necessary to supply what 

 otherwise might have been a gap in memory. 



There may be other causes for similar instances, but the above 

 will satisfactorily explain some oases, and simple explanations are 

 preferable to far-fetched ones. S. V. Clevenger. 



Chicago, 111. 



BOOK-REVIEWS. 



Hereditary Oenius : An Inquiry into Its Laws and Consequences. 

 By Francis Galton, F.R.S., etc. London and New York, 

 Macmillan & Co. 379 p. 8". $2.50. 



Finger Prints. By Francis Galton, F.R.S. London and New 

 York, Macmillan & Co. 216 p. 8". |2. 



The 6rst edition of Galton's " Hereditary Genius" appeared as 

 long ago as 1869, and that before us is the second. His observa- 

 tions excited considerable attention, for, although he dealt with 

 familiar facts for the most part, his methods of analyzing and 

 stating them were new, and the results which be arrived at were 

 not merely unexpected, to an English public they were startling. 



These results are by no means modified to a feebler expression 

 in the present edition. A few examples will illustrate this. On 

 page 132 he says, " I look upon the peerage as a disastrous insti- 

 tution, owing to its destructive effects on our valuable races." 

 Of the Christian Church in earlier centuries he writes: "She 

 brutalized human nature by her system of celibacy, and de- 

 moralized it by her system of persecution of the intelligent, the 

 sincere, and the free." Nor does he allow that she is much better 

 to-day. She keeps us " in antagonism with the essential require- 

 ments of advancing civilization," and "leads us to a dual life 

 of barren religious sentimentalism and gross materialistic habi- 

 tudes." 



These severe arraignments are not the hasty attacks of a polem- 

 ist, but the calm reflections of a mature student of social statis- 

 tics and historic data. If they shock any one by their force, be 

 should study the volume, and ask himself whether they are not 

 amply justified by the array of evidence it contains. The title, 

 " Hereditary Genius," falls singularly short of the real scope of 

 the work. It is, in fact, a comprehensive study of the means 

 of improving the human race through wiser arrangements for 

 reproduction. The precepts it inculcates will convince as well 

 as surprise the reader, and many an ancient saw is pricked and 

 disappears like a bubble by the keen points of the author's reason- 

 ing. 



