A^A TURE 



[November 2, 1S93 



sphere of molecular action was measured exactly. A number of 

 physical problems were treated, with which in England Lord 

 Kelvin, the late Prof. Clerk Maxwell, Prof. Reinold, Prof. 

 Riicker, Lord Rayleigh, and others have also occupied them- 

 selves. The criticism therefore seems not justified. 



I know very well that in Germany several representatives 

 of the descriptive natural sciences do not agree with my views 

 pbout the structure and the movement of protoplasm. For instance, 

 Prof. Pfefifer^ reproached me with "'having, without deducing 

 my views from admissible foundation on experience in organism, 

 exclusively constructed them by physical experiments, and 

 thereupon demanded, in an unwarranted manner, a peri- 

 pheric oil-layer for protoplasm." 



Her*:, too, let me remark, that I concluded the existence of this 

 peripheric oil-layer from the globular form of the surface of pro- 

 toplasm in plasmolysed cells and that I tried for months to find 

 in living cells the characteristic periodic spreading, suspected by 

 me, on the inner side of the hypothetical oil-layer. I have 

 several times observed this spreading and the destruction of the 

 globular form caused thereby. The observations of living cells 

 liave led me to fresh physical experiments, which I published 

 'in the year lS88, together with my theory nf the siructure and 

 movement of protoplasm. These theories I have always found 

 corroborated in the continuation of my researches since l888. 

 My adversaries, on the csntrary, have as yet not given a satis- 

 factory physical explanation for the above stated phenomena, 

 the globular form of protoplasm surface and the movements in 

 the vicinity thereof. Up to the present day I believe my views 

 to be correct and irrefuted. 



The facts observed and the physical conclusions inferred 

 by me, may appear extraordinary and not very intelligible to 

 another science, but they are none the less correct and useful. 

 Biological science must, well or ill, take into account 

 the fact that the development of the cell and the life of the 

 organic nature depends on masses and layers which cannot 

 be perceived by the microscope alone. 



Heidelberg, October 22. Georg Quincke. 



Human and Comparative Anatomy at Oxford. 



I\ the article which appeared in your last number under the 

 above heading, expressions occur which may, I think, lead to 

 misconception as to the position of the department of Human 

 Anatomy. It is of such importance in the interest of scientific 

 medical education that the academical teaching of human ana- 

 tomy should «i7^' consist merely in "technical training in an- 

 thropotomy," that I cannot allow the statement that the teach- 

 ing of the subject in Oxford is of this nature to pass without 

 comment. Had the writer of the article in question taken the 

 troulile to inquire of the University lecturer here, or of any of 

 the University professors of human anatomy elseivheie, for 

 instance at Cambridge, Edinburgh or Dublin, or had he con- 

 sulted any of the leading text-books of the subject, he would 

 have found that its scope is much more extended than he sup- 

 pose-. The misstatement having been made, however unin- 

 tentionally, must be corrected. 



Let me add that the department, which was founded in 1885, 

 was not connected in its oritjin with the department of Com- 

 parative Anatomy, and has had no relation whatever with it 

 •smce. T. BtJRDO.N' Sanderson. 



Asymmetrical Frequency Curves. 

 Owing to the haste with which I looked through the proof 

 of my letter in last week's Nature (p. 615) two slips escaped 

 me, which 1 hasten now to correct. The ordinates in the dia- 



c ' I.2.C 



gram should have been marked 



<S:c. , the factor - having been dropped. Further, the value for 



c 



c should have been 



_ \'2( J/i.,- 



U4)m.j 



my a having been converted into a square power. 



The method applied to Dr. Venn's curve fits it with an 

 accuracy only surpassed by the generalised orobability curve 

 itself. ^ Karl Pearson. 



University College, October 28. 



^ Pfeffer, "Zur Kenniniss der Plasniahautund der Va~uo!en " (Ai/ianJl. 

 Leipiig, Akad. math. pkys. Kiasse, 1S90, .\vi. p. 270. 



NO. 1253, VOL. 49] 



Telegony. 



As already stated in my previous letter, I have discussed this 

 subject in my recently published " Examination of Weismann- 

 ism " more fully than in Nature. If '■ M. D. H. " (Nature, 

 October 19) will consult the reference given in that letter to 

 this work, he will find the facts to which he directs my atten- 

 tion are there given, together with certain reasons for conclud.- 

 ing that they do not materially aflect the point in question. 



Hjeres, October 26. George J. Romanes. 



AN ORNITHOLOGICAL RETROSPECT. 



TOURING the year 1S92 there were at least three publi- 

 -*-^ cations which are of great value to ornithologists, 

 though from somewhat different points of view. They are 

 Prof. .St. George Mivarts little work on the " Elements of 

 Ornithology,"! Dr. Gadow's "Classification of Birds," 

 published in the Proceedings of the Zoological 

 Society, and Capt. Bendire's '• Life-Histories of North 

 American Birds." 



To thoroughly appreciate the value of Prof. Mivarts 

 " Elements "' one has to be the curator of a museum. 

 r^Iany people, like myself, must have been puzzled by 

 the frequent demand for an elementary, but comprehen- 

 sive book on birds, such as a man can carry with him on 

 his travels, and many people about to journey abroad 

 have asked me for a small book which would explain to 

 them what certain birds were like. I prophesy that Prof 

 IMivart's book will make many collectors, and its handy 

 size is one of its best features. There have been many 

 introductory works on ornithology published in this 

 country and America, notably those of Pro.*". Elliott Coues, 

 but nearly all of them are too bulky, and that is the fault 

 with the most popular works, such as the "Standard 

 Natural History" and Cassell's "Popular Natural 

 History." Commencing in an easy and unconstrained 

 manner, Prof. Mivart in his Introduction leads his 

 pupil on through the various forms of bird-life, his object 

 being not to weight the tyro with too heavy material for 

 study at starting. .AH the leading Avian types are passed 

 in review and they are illustrated by some admirable 

 woodcuts by Mr. Keulenians, drawn especially for the 

 work. It is, therefore, possible for any one to under- 

 stand what a particular form of bird is like, the only 

 drawback to this mode of illustration being the impossi- 

 bility of illustrating the subjects on the same scale, so 

 that some of the smaller forms appear to be larger than 

 they really are in comparison with the bigger birds. This 

 was, however, unavoidable. 



Three chapters (pp. 134-234) are devoted to the 

 anatomy and osteology of birds, and a fifth chapter 

 deals with their geological and geographical relations 

 (pp. 235-250). That on the "Classification of Birds" 

 summarises the chief characters for each order, sub- 

 order, and family, and lastly there is an enumeration of 

 the genera with the number of species in each. This is 

 of course mainly derived from the British Museum 

 " Catalogue of Birds," and 1 find that on adding up 

 Prof. Mivarts figures, the number of known species 

 is 11,900. The last time that a computation of the 

 number of birds was made was in 1871, when the late 

 Mr. G. R. Gray finished his " Handlist of Birds," and 

 admitted 11,162 species as then known. This was 

 probably a correct estimate, as I have generally found 

 that the " Handlist " contained about enough false species 

 to counterbalance the number of species described since 

 the work was issued. For similar reasons, Prof. Mivart's 

 estimate of 12,000 species will turn out to be approxi- 

 mately correct, and then by adding the number of 

 species described since his book was published, and 

 others discovered since the issue of the " Catalogue of 



y St. George Mivart, "Birds: The Elements.of Ornithology." Svo, pp. 

 vi.-329. (Ltndon, 1S92.) 



