NATURE 



[August i8, 1910 



OUR BOOK SHELF. 



The House-fly, Mtisca domestica, Linnaeus: a Studv 

 of its Structure, Development, Bio)wmics, and 

 Economy. By Dr. C. Gordon Hewitt. Pp. xiv + 

 196+10 plates. (Manchester: University Press, 

 igio.) Price 20s. net. 

 In this volume the student will find, in a convenient 

 form, the three valuable papers on the common house- 

 fly which Dr. Hewitt contributed to the Ouartcrlv 

 Journal of Microscopical Science in iqoy, iqo8, and 

 1909. In the first the author deals with the anatomy 

 of the fly, in the second with the habits, development, 

 and anatomy of the larva, and in the third with the 

 bionomics, allies, and parasites of the insect, and its 

 relations with human disease. The volume opens 

 with a brief introduction, and concludes with three 

 short appendices, comprisinfj some facts ascertained 

 since the issue of the original papers. 



The first part is noteworthy for a full and original 

 description of the tracheal system of the fly. In his 

 account of the proboscis, Dr. Hewitt agrees with most 

 recent students of the jaws of Diptera in regarding 

 the palps as maxillary and the sucking organ as 

 labial; in this, as in some other interpretations, he 

 differs from the opinions expressed in Lowne's well- 

 known work on the blow-fly. In the second part, 

 especial attention has been paid to the muscular 

 system of the larva, which is described and figured in 

 detail. The rate of development is verv rapid, and 

 there are only three larval instars. While horse-dung 

 is the most usual food of the house-flv maggot, the 

 female fly mav lav her eggs in a wide variety of 

 unclean and decaving animal and vegetable sub- 

 stances, in anv of which the larvae can be success- 

 fully reared. Hence it follows that house-flies must 

 frequently carry disease germs which thev have 

 abundant opportunity of introducing into human food, 

 and the name "typhoid fly," which some .American 

 entomologists are trying to afiix to Musca domestica, 

 might be justified from certain unpleasant but instruc- 

 tive records which Dr. Hewitt quotes of the proximitv 

 of tvphoid-infected privies to dairies. 



The hygienic bearing of the insect's relations with 

 mankind is seriously and temperatelv discussed by the 

 author, who jileads for such protection or destruction 

 of substances in which the eggs are laid as mav 

 effectuallv reduce the numbers of the species, and foi 

 the covering of food substances, like milk and sugar, 

 on which the flies habitually alight. The book affords 

 an excellent illustration of the amount of original 

 and useful work that mav be done on the commonest 

 and best known of animals. G. H. C. 



The Science of Happiness. Bv Dr. H. .S. \Mlliams. 



Pp. vi-l-350. (London and New York: Harper and 



Brothers, n.d.) Price ys. 6d. net. 

 This mitrht well be given the still wider title of "The 

 Art of Living," for it concerns itself with human 

 activity of all kinds. It is a pleasantlv written series 

 of papers on such topics as how to eat, how to sleep, 

 how to think, and even how to die, and, though a 

 trifle diffuse and flat — revealing the fluent writer with 

 not much that is original to say — it contains much 

 wisdom of an everyday kind, and many apt quotations 

 to spice up the text. 



_ Dr. Williams is not a food faddist, and almost 

 his only criticism on this head is that most of us eat 

 too much. But he would not cut down the number 

 of meals to anything below three per dav, for he 

 believes that, on the whole, experience endorses that 

 number. He condemns alcohol, tobacco, and — less 

 vehementlv — tea and coffee. Exercise ought to be 

 gentle and regular, and we may sleep eight hours per 

 NO. 2139, VOL. 84] 



night if we want to, but must not doze off for another 

 fortv winks after a good night's rest. -An interesting 

 point is that Dr. Williams believes the stunted growth 

 of the Latin races to be the result of the habit of 

 wine-drinking. 



.A,s to the mind, the author counsels the strenuous 

 life, as befits a good American, and stimulative 

 examples are quoted. Mezzofanti learned fifty-seven 

 languages. Plinv (the elder) never left off studying 

 except when asleep or in his bath, and after the latter 

 he had a book read to him while he was being rubbed 

 dry. .\s to opinions, religious or political, think them 

 out for yourself. Ask vourself why you believe this 

 or that. Do not be content to inherit opinion as you 

 inherit the colour of hair. or eyes. Work your way to 

 rational conviction. 



It is all verv chatty, pleasant and sensible ; and 

 we do not mean anv cheap satire when we say that 

 the book is beautifully bound and produced. 



Rinaldo's Polvgeneric Theory: a Treatise on the Be- 

 ginning and End of Life. By Joel Rinaldo. Pp. 

 12-^. (New York : 206 West 41st Street.) 

 To Mr. Rinaldo, " evolution " is like the red rag to 

 the proverbial bull ; and, like most violently biased 

 people, he has not given sufficient study to the object 

 of his attack. For example, in arguing for the special 

 creation of man, he says it is "ridiculous" to explain 

 by migration the similarities found in widely separated 

 countries. But evidently he does not realise the 

 length of duration in past time of a being justifiably 

 called man, for, even if we assume that duration to 

 go back no further than the Miocene period, there is 

 ample scope for almost unlimited migration (e.g. 

 there was land at this period probably across the 

 North .\tlantic) ; and, indeed, human migration is 

 not essential to the theorv ; migration of lower animal 

 forms, in still more remote periods, would do nearlv 

 as well. Mr. Rinaldo seems to think that evolution 

 implies an .Adam and Eve from whom all mankind 

 are descended. .As a matter of fact, the theorv of 

 biological evolution woidd not be invalidated if it 

 were proved that man appeared on various parts of 

 the earth's surface at the same time, for these primi- 

 tive human beings would be descended from other 

 and less complex forms of life — animals of anthropoid 

 but not vet human structure. 



Mr. Rinaldo, though an amateur, is well read in 

 some directions, but he has not studied Darwin and 

 Huxlev thoroughlv, not to mention more recent 

 biologists, and his judp'ment is warped, like Carlyle's, 

 by mistaken notions of the "monkey damnification of 

 man." The wish be'ing father to the thoueht, he 

 asserts that "Darwinism is alreadv dead." If he will 

 read a book reviewed in Natl'KE, July 14, he will see 

 that one of our greatest authorities — Sir E. Ray 

 Lankester — thinks it is still very much alive. But we 

 hardly expect that he will be converted. 



Letters from High Latitudes, being Some Account of 



a Voyage in 1856 in the Schooner-Yacht "Foam" 



to Iceland, Jan Mavcn, and Spitzbergoi. By Lord 



Dufferin. With an introduction by Dr. R. W. 



Macan. Pp. xxxvi + 261. (London : Henry Frowde, 



O.xford Ljiiversity Press, 1910.) Price li. net. 



These entertaining letters were first published in 



1856, and are so well known that any words of praise 



are unnecessary. The master of University College, 



Oxford, in his introduction, says: — "The letters are, 



or ought to he, a World's Classic; Mr. Frowde's 



happy enterprise has made that concept a realitv." 



It mav be noted that the volume is the hundred and 



fifty-eighth to be added to the series of "The World's 



Classics." 



