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SCIENCE. 



[N. S. Vol. XXIV. No. 603. 



be compared, the two stages, which can be 

 most readily determined to be correspond- 

 ent, being the first and the last. This, to- 

 gether with the greater amount of differentia- 

 tion found in the adult stage, leads him to 

 the conclusion that end stages in the ontogeny- 

 are more important for purposes of compar- 

 ison, than any other stages. The rigid ap- 

 plication of this principle leads him to some 

 very unusual conclusions ; e. g., most zoologists 

 will be astonished at the statement that 8ac- 

 culina is not a Crustacean, because in its 

 adult condition it has lost the Crustacean 

 characters which it possessed as a larva. Sim- 

 ilarly the statement that the group Chordata 

 is inadmissible because tunicates, Amphioxus 

 and vertebrates are very unlike in the adult 

 condition, though their larvse show funda- 

 mental resemblances, seems to the writer to 

 be out of harmony with the broad and liberal 

 method of comparison advocated in the clos- 

 ing section of the chapter, viz., ' to neglect 

 nothing, to consider every property, kind of 

 individual, every embryonic stage,' etc. 



The chapter on the ' Relative Values of 

 Morphological Characters' deals with many 

 interesting questions. The author concludes 

 that types of symmetry — ^radial, spiral, bi- 

 lateral — are of little phylogenetic significance, 

 but that metameric segmentation is of great 

 importance. An excellent review of the 

 theories as to the origin of metamerism is fol- 

 lowed by the author's view that metamerism 

 has arisen, not from asexual reproduction, but 

 from division of organs, * Just as one cell 

 gives rise to others by division, so one organ 

 produces others by division.' 



In general the conclusion is drawn that the 

 most important of all morphological char- 

 acters for the purpose of comparison are those 

 which relate to the relative position and con- 

 nection of parts. 



In the tenth chapter the ' Criteria of Racial 

 Advancement' are discussed. Whether an or- 

 ganism is to be regarded as ' high ' or ' low,' is, 

 according to the author, dependent entirely 

 upon the length of its line of descent, irre- 

 spective of its final complexity or simplicity. 

 This again leads to some very unusual conclu- 



sions and causes one to doubt the value of 

 any such definition. 



Limits of space have made it necessary to 

 consider only a few of the subjects treated in 

 this work, and the author's conclusions have 

 been stated without presenting the cogent, if 

 not always convincing, arguments by which 

 these conclusions are reached, nevertheless 

 this review will serve to show the great extent 

 and importance of the subjects treated. The 

 author's intimate acquaintance with the great 

 wealth of phenomena and with the extensive 

 literature dealt with in this book, makes it 

 one of particular importance and value to 

 biological students. 



E. G. CONKLIN. 



SCIENTIFIC JOURNALS AND ARTICLES. 



The Journal of Comparative Neurology and 

 Psychology for July contains the following 

 articles: Dr. G. E. Coghill describes the 

 ' Cranial Nerves of Triton tceniatus,' compar- 

 ing the microscopic anatomy and nerve com- 

 ponents with Amhlystoma and the forms de- 

 scribed by Driiner. ' Retrograde Degenera- 

 ton in the Spinal Nerves,' by S. Walter Ran- 

 son. An experimental study of the atrophic 

 changes in both spinal nerves and the cells 

 of the spinal ganglia and spinal cord with 

 special reference to the differences between the 

 typical Wallerian and the retrograde degenera- 

 tion. ' The Primitive Pores of Polydon 

 spathula/ by Herbert D. Kistler, describes 

 with a plate the peculiar sense organs on the 

 bill of the spoon-bill catfish. ' The Reactions 

 of Crayfish to Chemical Stimuli,' by James 

 Carleton Bell. A careful examination of the 

 whole body surface to discover its sensitive- 

 ness to various types of chemical solutions. 

 An editorial on abnormal psychology and book 

 notices complete the number. 



The Botanical Gazette for July contains 

 the following papers : E. C. Jeffrey and M. A. 

 Chrysler discuss the Cretaceous Piiyoxyla, de- 

 scribing two new species, one from the Middle 

 Cretaceous of Staten Island, the other from 

 Massachusetts. Certain differences from 

 modern pines are pointed out and regarded as 

 ancestral. H. L. Shantz publishes a result of 

 his study of the vegetation of the Mesa region 



