618 



SCIENCE. 



[N. S. Vol. IX. No. 226. 



ontology the maguificent limbs of four mon- 

 strous dinosaurs commanded special atten- 

 tion. 



Similarly in Zoology the beautiful new 

 case illustrating the nesting habits of the 

 browQ pelican rather out ran in popular 

 favor other objects of great scientific inter- 

 est. 



As may be inferred even from the above 

 brief and unsatisfactory sketch, the exhibi- 

 tion was as wide iu its scope as it was scien- 

 tifically interesting in its details. It must 

 have been seen to be appreciated, and the 

 thanks of those who did see it are due to 

 the zeal of the exhibitors, especially those 

 out of town, among whom should be men- 

 tioned Princeton, Harvard, Johns Hopkins 

 and Chicago Universities, Lick and Yerkes 

 Observatories, the United States, Maryland 

 and New York Surveys. 



William Hallo.ck, 

 Chairman of Committee. 



SCIENTIFIC BOOKS. 

 Lectures on the Evolution of Plants. By Douglas 

 Houghton Campbell, Ph.D., Professor of 

 Botany in the Leland Stanford Junior Uni- 

 versity. New York, The Macmillan Com- 

 pany. 1899. 12mo. Pp. viii + 319. 

 Professor Campbell is probably the foremost 

 of the small group of what may be termed the 

 philosophical botanists in America, and he is, 

 no doubt, better prepared to discuss the ques- 

 tions taken up in this book, at least in so far as 

 they deal with the archegoniates and seed 

 plants, than any other of our students of plants. 

 Some years ago he brovight out his book ' The 

 Structure and Development of the Mosses and 

 Ferns,' iu which he treated the subject in such 

 a modern way as to give new meaning to what 

 had to too great a degree been mere dry detail. 

 In no uncertain words he traced the genetic 

 relationship of group to group, and the student 

 following him was made to feel that the fact of 

 relationship was real and necessary, and not 

 doubtful or shadowy. 



In the little book before us the author dis- 

 cusses, in succession, the conditions of plant 



life, the simplest forms of life, algis, fungi, 

 mosses and liverworts, ferns, horsetails and 

 club-mosses, gymnosperms, monocotyledons, 

 dicotyledons, geological and geographical dis- 

 tribution, animals and plants, influence of en- 

 vironment, and at the end brings together 

 his results in a chapter entitled ' summary and 

 conclusions.' 



We can do no better in endeavoring to give 

 our readers an idea of the author's treatment 

 and conclusions than to quote a sentence here 

 and there from his final chapter, as follows : 

 "All plants agree closely in their essential cell 

 structure, the typical cell having a cellu- 

 lose membrane and a single nucleus." "The 

 lowest plants are mainly aquatic, and it is ex- 

 ceedingly probable that this is the primitive 

 condition of plant life." "The peculiar group 

 of motile green algas, the Volvocinese, probably 

 represents more nearly than any existing forms 

 the ancestral type of all the higher green 

 plants. These ciliated algse are also probably 

 related to certain colorless flagellate Infusoria^ 

 which in turn may represent the starting-point 

 for the whole group of Metazoa among animals. 

 It is not unlikely that the separation of the 

 two great branches of organisms, plants and 

 animals, took place among the Flagellata."^ 

 " Starting with this primitive motile unicellular 

 organism, there have evidently arisen a num- 

 ber of independent lines of development result- 

 ing in very divergent types of structure." 

 "In these lowly organisms there is no clearly 

 marked line between vegetative and reproduc- 

 tive cells." 



' ' The increasing complexity of the plant body 

 has been accompanied by a corresponding special- 

 ization of the reproductive parts. " " The origin 

 of the Phreophycese, or brown algte, from free- 

 swimming brown flagellate organisms, is by no 

 means unlikely, and if this be shown to be the 

 case they must be considered as a line of devel- 

 opment parallel with the Chlorophyceae, rather 

 than an off-shoot from these." " The relation- 

 ship of the fungi is still an open question." 

 " The ancestors of the higher green plants must 

 be sought among the simple fresh-water greea 

 alga3. The genus Coleochxte, the most special- 

 ized of the Confervacese, is the form which 

 shows the nearest analogy with the lower 



