906 



SCIENCE. 



[N. S. Vol. XVII. No. 440. 



in English, or been translated into that lan- 

 guage. Its interest is scarcely less for the 

 physiologist and for the botanist concerned 

 with the problems of alterations and adapta- 

 tions of structure. D. T. MacDougal. 

 New York Botanical Garden, 

 Bronx Pakk. 



Lelirbuch der vergleichenden Entwichlungs- 

 geschichte der wirhellosen Thiere. Allge- 

 meiner Theil. Erste und Zweite Auflage. 

 Zweite Lieferung. By E. Koeschelt and 

 K. Heider. Jena, Gustav Fisher. 1903. 

 The second instalment of the general part 

 of Korschelt and Heider's ' Lehrbuch,' which 

 has recently appeared, maintains the high 

 standard of excellence which we have learned 

 to expect from these authors. The instal- 

 ment includes only the sixth chapter, that 

 dealing with the maturation of the germ cells 

 and with the phenomena of fertilization, but 

 it runs to more than two hundred large oc- 

 tavo pages and contains over eighty figures. 

 These numbers will give some idea of the 

 comprehensiveness with which the subjects 

 named have been treated, especially if it be 

 remembered that not a little collateral ma- 

 terial was considered in the first instalment 

 of the work and is, therefore, omitted or 

 merely referred to in the present part. 



When all is of such general excellence it 

 may seem invidious to make special mention 

 of certain of the sections. In section IV., 

 however, there is presented an admirable 

 statement and discussion of the maturation 

 divisions in their relation to the reduction 

 question, and in its presentation certain new 

 terms are introduced to indicate the three 

 methods of maturation division recognized by 

 Hacker. To the method, observed by Boveri 

 in Ascaris, in which both the divisions of the 

 chromosomes are longitudinal and in which, 

 accordingly, there is no reduction division in 

 the Weismannian sense, the term eumiiotic is 

 applied, since it is the method characteristic 

 of ordinary somatic mitoses. For that 

 method in which one of the chromosome divi- 

 sions is transverse and the other longitudinal 

 the term pseudomitoiic is suggested, and this 

 method is subdivided into a method of post- 



reduction division in which the so-called re- 

 duction division succeeds the equation division 

 and a method of prcsreduction division in 

 which the reduction division is the first to 

 occur. The possibility of a fourth method in 

 which both divisions are reduction divisions 

 is admitted, but it is held that at present its- 

 occurrence is not proved. 



An excellent section is also_ that on the 

 maturation of parthenogenetic ova, in which 

 the question of the development of ova with a 

 subnormal number of chromosomes is con- 

 sidered. 



As in the preceding instalment of the work 

 the statement of facts is throughout thorough, 

 clear and well arranged, and opportunity is 

 taken to discuss fairly their bearing on gen- 

 eral questions, sections of great interest being 

 devoted to the significance of the numerical 

 reduction of the chromosomes in maturation, 

 to sex determination, to the significance of 

 fertilization, and as an appendix there is added 

 an excellent review of the theories of heredity 

 and the allied theories of differentiation. 



The figures are throughout well chosen and 

 reproduced and there is an extensive bib- 

 liographical list. J. P. McM. 



SCIENTIFIC JOURNALS AND ARTICLES. 



The American Anthropologist for January- 

 March (Vol. v.. No. 1), recently published, 

 contains an exceptionally large number of 

 articles, in addition to the usual book reviews, - 

 periodical literature and anthropologic mis- 

 cellanea. ' The Native Languages of Cali- 

 fornia ' are treated, with seven plates, by Drs. 

 Roland B. Dixon and A. L. Kroeber, the 

 classification of these interesting linguistic 

 groups dealing with structural resemblances 

 rather than with definite genetic relationships 

 — the aim being to establish not linguistic 

 families, but types of families. The illus- 

 trated article, ' Sheet-Copper from the Mounds 

 is not necessarily of European Origin,' by 

 Mr. Clarence B. Moore, with a discussion by 

 Mr. Joseph D. McGuire and others, is an 

 able presentation of both sides of a long-dis- 

 puted question in American archeology. Bear- 

 ing on the same theme is an article by Warren 

 K. Moorehead, ' Are the Hopewell Copper Ob- 



