October 17, 1907] 



NA TURE 



6ir 



ductive systems and embryology. The author has 

 wisely chosen to describe only the general features of 

 the muscular system ; a more detailed account would 

 have been beyond the scope of the present memoir. 

 The ventral tube, characteristic of Collembola, present 

 as a papiUiform organ on the mid-ventral aspect of 

 the first abdominal segment, is formed, as is shown 

 by development, by the fusion of a pair of appendages. 

 The various functions which have been ascribed to 

 this organ are set forth. The author records his ob- 

 servations in support of the view that its primary 

 function is that of an organ of adhesion, but he also 

 believes that it plays an important part as a respir- 

 atory organ, in virtue of the ease with which blood 

 flows into it and distends its two terminal thin-walled 

 vesicles. He confirms on Anurida the observations of 

 Willem and Hoffmann on other Collembola, that the 

 secretions of two pairs of cephalic glands flow into a 

 ventral groove leading from the head to the ventral 

 tube, which they serve to moisten. In the chapters 

 on the general structure, classification and affinities 

 of the Collembola, the author concludes that there are 

 no grounds for regarding these animals as degenerate ; 

 they show aflinities with the Thysanura (especially in 

 having a pair of mouth appendages — the maxillulae — 

 intercalated between the mandibles and first maxillae), 

 and, by reason of certain generalised features, to the 

 lower Arthropoda. The memoir also contains addi- 

 tional remarks on other marine insects, and an exten- 

 sive bibliography relating to papers on the Collembola 

 published since Lord Avebury's monograph. 



(2) In selecting hxgia oceanica for description as a 

 tvpe of the Isopoda, Mr. Hewitt has made an excel- 

 lent choice, for not only is this the largest British 

 Isopod, but it is intermediate between the aquatic and 

 terrestrial forms. .Mthough specimens are usually 

 found just above high-water mark, in deep cervices 

 of rocks or quay-walls, the author found them at St. 

 Kilda on the top of a hill 450 feet above sea-level, to 

 which altitude the sea-spray often reaches. It was 

 remarkable that most of the examples found at this 

 height were females, which do not descend to sea-level 

 to feed, but probably do so when liberating the young 

 from their brood-pouches, for large numbers of young 

 individuals were found under the rocks between tide- 

 marks, but none at the high level. Following the 

 description of the habits are clear and concise accounts 

 of the external characters, the various systems of 

 organs, and the development. The eyes are described 

 in some detail. In each ommatidium there are two 

 cone-cells, each of which secretes a hemispherical, 

 transparent mass. These two masses, W'ith their flat 

 sides apposed, form the cone on the proximal side 

 of which the cone-cells further produce two sub- 

 cylindrical accessory cones, an interesting and excep- 

 tional feature of the eye of Ligia. 



(3) The present volume on Aiitedon bifida is Mr. 

 Chad wick's second contribution to this series of 

 memoirs, his previous one, on Echinus, having been 

 published in 1900. Detailed and useful descriptions, 

 with excellent figures, are given of the various parts of 

 the skeleton and of the three nervous systems and 

 their functions. The other systems of organs and 



NO. I 98 I, VOL. 76] 



the development are w-ell treated. The author is in- 

 clined, but without giving reasons, to regard the sac- 

 culi as excretory structures; he holds that .the view- 

 that they consist of reserve material for use in the re- 

 generation of lost or injured parts is discounted by 

 the fact that sacculi are not present in the allied genus 

 Aclinometra, in which, nevertheless, regeneration pro- 

 ceeds quite as actively as in Antedon. The account of 

 the axial organ contains no discussion of the many 

 functions which have been ascribed to it, but the 

 author has observed that, at the breeding season, the 

 epithelial cells lining the tubules of the organ break 

 away and become amoeboid, suggesting that at this 

 period, at any rate, the axial organ is a site of form- 

 ation of amoebocytes. J. H. A. 



A LIFE OF SIR WILLIAM FLOWER. 

 Sir William Flower. By R. Lydekker, F.R.S. 

 Pp. vii+igi. (English Men of Science Series.) 

 (London : J. M. Dent and Co., igo6.) Price 

 2S. 6d. net. 



IT will be long ere the name of William Henry 

 Flower is forgotten by those in this country who 

 are ir>terested in scientific zoology and in the progress 

 and development of zoological museums ; and the 

 sketch of his life and work which Mr. Lydekker has 

 put together in the present volume, a small one in- 

 deed, though rich in interesting material, w-ill be much 

 valued by those especially who had the advantage of 

 personal acquaintance with the great museum con- 

 servator. 



As Mr. Lydekker has indicated in his preface, the 

 present work is more devoted to the scientific than 

 to the personal and social side of Sir William Flower's 

 career. Nevertheless, the opening chapter deals with 

 his birth, parentage, education, marriage, general 

 career, and with his lamented death at the age of sixty- 

 seven, in a manner which is both sympathetic and 

 interesting. The remaining seven chapters are 

 devoted to his worlc as a scientific worker and as a 

 museum conservator or director, and the value of the 

 work which he performed in both capacities is well 

 brought out by the writer of the memoir. 



As all zootomists know. Sir William Flower's 

 original work lay almost entirely in the domain of 

 mammalian anatomy and general classification of 

 mammals, and his name will go down to posterity as 

 the discoverer of many new and important facts, and 

 as the propounder of more satisfactory views on many 

 matters of zoological interest. We need only mention 

 his demolition of Owen's classification of mammalia 

 bv their brains ; his discovery of the fact that in the 

 marsupial dentition only a single pair of teeth on each 

 side is replaced by vertical succession ; or his classi- 

 fication of the carnivorous mammalia according to the 

 characters of the base of the cranium. Everyone 

 knows also that Sir William Flower w^as a first-class 

 authority on the Cetacea, and that in his later years 

 he devoted much attention to anthropological studies. 

 In the chapters on Sir William's work as conservator 

 of the museum of the Royal College of Surgeons, as 

 director of the Natural History Museum, and on his 



