124 



NATURE 



[October i8, 1917 



indebted to him for providing in this convenient 

 form a trustworthy guide to the external and inter- 

 nal structure of dragonflies at various stages of 

 their life-histories. He knows the literature of the 

 order well and furnishes a full bibliography, but 

 much of the information in the book is due to his 

 own careful studies, pursued first in England and 

 afterwards in Australia, where he now resides. 



The "mask," or modified labium, of the dragon- 

 fly larva is one of the most remarkable of pre- 

 daceous organs. Mr. Tillyard supports the view 

 that its lateral lobe is formed by the labial palp ; 

 in this he is probably right, but his use of the 

 term "exopodite" for the palp is less justifiable, 

 as it is very doubtful if the crustacean exopodite 

 is represented at all in any insectan appendage. 

 The adaptation of the larvae to aquatic life is of 

 much interest, and the various types of tracheal 

 gills found among them receive especially full 

 treatment, though the author does not fail to 

 emphasise the imperfection of our knowledge of 

 the physiology of the respiratory process. Per- 

 haps the most abnormal organs possessed by 

 dragonflies are the problematical sclerites on the 

 second abdominal segment that form the genital 

 armature ; Mr. Tillyard supplies a clear description 

 of these with original figures. Embryology is 

 treated with relative brevity, but there are some 

 welcome original observations on modes of egg- 

 laying by various female dragonflies. The phylo- 

 geny of the Odonata is discussed with reference 

 to extinct genera from the Coal Measures on- 

 wards, and there is a full chapter on geographical 

 distribution, accompanied by a map. Mr. Tillyard 

 does not disdain, like some modern students, to 

 retain the classical " regions " which may be used 

 so as to indicate important distributional facts, 

 if the student remembers that they have no 

 guarded land frontiers. Detailed systematic treat- 

 ment is outside the scope of the book, but the 

 characters of families and sub-families are suffi- 

 ciently elucidated to set a collector profitably to 

 work in any part of the world, while a synopsis of 

 the British species is welcome to the home-keeping 

 student. There are four plates and 188 text- 

 figures, for the most part excellent both in 

 draughtsmanship and reproduction ; the repre- 

 sentations of the complicated wing-nervurations 

 that form such important characters for the classi- 

 fication of dragonflies deserve a special word of 

 praise. 



Even in these volumes echoes of the war are 

 to be met with. Mr. Tillyard gratefully records 

 how his manuscript and six sets of proofs have 

 passed to and fro between Australia and Cam- 

 bridge since July, 191 5, "without the loss of a 

 single item." Dr. Marshall and Mr. Arrow 

 acknowledge the courtesy of various German 

 students of beetles who, in the days of inter- 

 national scientific helpfulness, facilitated the ex- 

 amination of type-specimens. One trusts that 

 such once friendly entomologists will be glad to 

 know that their fellow-countrymen failed to destroy 

 the results of Mr. Tillyard 's prolonged and peace- 

 ful labours. G. H. Carpenter. 

 NO. 2503, VOL. 100] 



THE INDIVIDUAL IN SOCIETY. 

 Community : A Sociological Study, being an 

 Attempt to set out the Nature and Fwidamental 

 Laws of Social Life. By Dr. R. M. *MacIver. 

 Pp. XV + 437. (London: Macmillan and Co., 

 Ltd., 1917.) Price 12s. net. 



DR. R. M. MACIVER'S study of community is 

 a plea for the validity and importance of the 

 individual life. The meanmg of society is found 

 within the constituent members. Social and in- 

 dividual claims are complementary to each other. 

 Individual autonomy is realisable only within 

 society. The liberty of the self proves itself in 

 the relation of the self with other selves ; for 

 freedom is but a means of life, and not life itself. 

 Social order involves the adjustment of individual 

 claims to each other. Communal life is charac- 

 terised by reciprocal action, and the wonder of 

 the universe is the essential harmony of personal 

 values working in and through society. 



In the development of social consciousness the 

 movement is at once both broad and deep. By 

 the strength of a common life we break down 

 the barriers of race and nationality, to find that we 

 have intensified our hold upon the things that 

 serve the well-being of individuality. 



The clear-cut opposition of life and environ- 

 ment, as popularly conceived, is false. Environ- 

 ment is but the external correlative without which 

 life would be futile and meaningless. The relation 

 of the two is essential. Change in either involves 

 change in the other. For Dr. Maclver "life is 

 that which feels and knows and wills, that 

 for which values exist and ' which itself 

 exists as value." It is a shaping force 

 expressing itself in character, of which en- 

 vironment may be the occasion or stimulus, but 

 not the source. The increasing control of the 

 individual over environment is secured in the 

 development of a social co-operation marked by 

 intelligence. In the evolution of society, rational 

 or purposive selection must ultimately replace 

 "natural selection." 



Dr. Maclver has given a fine and adequate 

 analysis of the meaning of society. The willed 

 relations of living beings are the primary social 

 facts, and "the ultimate social laws are those 

 which reveal the interrelations of the purposes of 

 living beings, their conditions and their conse- 

 quences." 



Community is defined as an area of common 

 life, with definite characteristics such as are given 

 in traditions, customs, manners, modes of speech, 

 i etc. It may transcend the State, in that it is not 

 territorially limited ; it may exist without a State, 

 as among the Eskimos. The State is "the funda- 

 mental association for the maintenance and de- 

 velopment of social order." Society involves 

 I co-ordinated rights and obligations embodied in 

 political law and enforced by communal power. 

 Law is the primary instrument of the State ; it 

 operates irrespective of the individual will. The 

 State, however, cannot directly affect the spiritual 

 life of its members. It can only deal with ex- 



