July 13, 1916] 



NATURE 



399 



and that in drawing- our conclusions we must 

 attend to the circumstances of the case. The 

 example he chooses is the dynamical one, where 

 we have a Lagrangian system in generalised co- 

 ordinates, reducible to 2T — m {x- + y^), \J = c, 

 where m, c are constants. One such system is 

 that of a particle under no forces ; another is a 

 gyrostat with two degrees of freedom, for which 

 X, y are angular co-ordinates (and therefore 

 periodic, so far as the actual motion is concerned). 

 All this is plain enough ; but when the lecturer 

 says, "The assemblage of all possible positions of 

 system (2) can be represented not on a plane, but 

 on the surface of an anchor-ring," the reader may 

 feel confused, especially since to trace the path 

 of any particular point of the gyrostat we must 

 introduce additio7ial co-ordinates. 



Prof. Hadamard emphasises (p. 17) the work 

 of Poincare on ordinary differential equations, 

 especially in the Journ. de Math., 1887 (on the 

 shape of curves defined by differential equations). 

 He also (p. 33) protests, we are glad to see, 

 against the over-analytical drift of current mathe- 

 matics. In his dealing with Green's theorem we 

 regret to see no reference to Mr. J. Dougall. 

 Doubtless this is due to ignorance ; but Mr. 

 Dougall's work is masterly and in the true spirit 

 of Green, and it is most unfortunate that it is 

 practically buried in a periodical which (for no 

 fault of its own) has no very wide circulation. 



■ The text, on the whole, seems to be a satisfac- 

 tory rendering of the French original ; " admit " 

 for "allow" or "assume," "effectively" for "as 

 a matter of fact," etc., are such common errors 

 that they are unlikely to lead to mistakes on the 

 part of the reader. The typ>ography is unusually 

 good, and a credit to the Columbia University 

 Press. G. B. M. 



W. B. TEGETMEIER. 

 A Veteran Naturalist: being the Life and Work of 

 W. B. Tegetmeier. By E. W. Richardson. 

 With an introduction by the late Sir Walter 

 Gilbey, Bart. Pp. xxiv + 232. (London: 

 Witherby and Co., 1916.) Price 10s. net. 



THIS is a pleasantly written sketch of the life 

 of a versatile naturalist, of strong^ly marked 

 individuality, whose name will be for long asso- 

 ciated with poultry and pheasants, homing 

 pigeons and bees, to the study of which he made 

 notable contributions. W. B. Tegetmeier (1816- 

 191 2) was the son of a doctor and also the grand- 

 son ; and he was himself more or less of a medical 

 student and apprentice for ten years (1831-41). 

 But an inborn attraction to birds and beasts, a 

 recoil from humdrum routine, and a conspicuous 

 absence of a bedside manner (as he said himself) 

 led him to teaching for a short time, and to 

 journalism for a very long time, and to a life of 

 fruitful zoological inquiry, especially along 

 economic lines. 



The story of Mr. Tegetmeier's life, which Mr. 

 E. W. Richardson, a son-in-law, has told with 

 directness and enthusiasm, shows how a man of 

 talent and industry, honestv and courage, wrung 



NO. 2437, VOL. 97] 



a livelihood out of unpromising circumstances, 

 and won the respect and affection of all worthy 

 men who knew him. For half a century Mr. 

 Tegetmeier was in charge of the poultry and 

 pigeon department of the Field, and for a score 

 of years he wrote regularly for the Queen. As 

 a consultant and expert judge he was incessantly 

 busy in connection with pheasants, poultry, 

 pigeons, and the like, and did important work in 

 setting a high standard of accuracy, both of 

 statement and action. 



Introduced by Yarrell to Darwin in 1855, he 

 enjoyed the master-naturalist's friendship for 

 twenty-five years, and the value that Darwin put 

 upon his observations is well known. It may be 

 recalled that Tegetmeier, who was a convinced 

 evolutionist, had strong suspicions as to the theory 

 of sexual selection, pointing out, for example, that 

 disfigured game-cocks were accepted just as 

 thoroughly as the dandiest of their rivals. In 

 connection with the Savage Club, of which he 

 was one of the founders, and in the pursuit of 

 various hobbies, Mr. Tegetmeier allowed himself 

 relaxation-, but it appears that he never went for 

 a walk or took a holiday. He was absorbed in 

 his work, almost always thoroughly enjoying it, 

 and he lived for nearly a century. 



Mr. Richardson tells us of Tegetmeier's early 

 "observation-hives," and how he once took a 

 swarm of bees from over the door of the Gaiety 

 Theatre, to the fearful delight of the spectators; 

 how he was interested in school " nature-study " 

 when the very idea was novel ; of his numerous 

 breeding experiments when neither Darwin nor 

 he knew of Mendel; of his realisation of the 

 importance of homing pigeons in ante-" wireless " 

 days; of his endless post-mortems, which some- 

 times rather embarrassed his household ; of his 

 interesting chronicling of the metamorphosis of 

 the axolotl ; and of much more besides, not for- 

 getting his anti-feminist prejudices. The delight- 

 ful biography is in its mood harmonious with the 

 sincerity of one who never suffered humbugs 

 gladly, and the numerous interesting illustrations 

 increase the impression of picturesqueness which 

 marked the man himself. Of a sceptical and 

 agnostic mood, he never disparaged religion ; and 

 when Mr. Richardson once asked him if he denied 

 the existence of God, he replied: "My boy, how 

 could I, when every leaf on every tree proclaims 

 its Maker, and is a living witness to the power, 

 wisdom, and providence of the Creator of the leaf 

 and of life and of all things ? " 



OUR BOOKSHELF. 



Modes of Research in Genetics. By Raymond 

 Pearl. Pp. vii+182. (New York: The Mac- 

 millan Co. ; London : Macmillan and Co., 

 Ltd., 1915-) Price 5^. 6d. net. 

 Dr. Raymond Pearl's book inquires into the 

 methodoloev of modern genetic science, and does 

 so with clearness, concreteness, and vigour. The 

 first chapter discusses the current modes of re- 

 search on heredity, by which is meant the complex 



