and Laboratory Methods. 1299 



CURRENT BOTANICAL LITERATURE. 



Charles J. Chamberlain. 



Books for review and separates of papers on botanical subjects should be sent to 



Charles J. Chamberlain, University of Chicago, 



Chicago, 111. 



REVIEWS. 



Grout, A. J. Mosses with a Hand-lens. 8vo, This convenient little book certainly 



pp. xi + 74. 1900. Published by the author, supplies a long felt need. It is a non- 



360 Lenox Road, Flatbush, New V ork City. . 



technical handbook of the more com- 

 mon and more easily recognized mosses of the Northeastern United States. Two 

 general keys are given, one based mainly upon structural characters and the 

 other based mainly upon habitat. With the aid of these keys, the descriptions 

 and Miss Thayer's numerous excellent illustrations, the student is enabled to 

 recognize about one hundred mosses. An illustrated glossary of bryological terms 

 is an important feature. It is a matter of common observation that experienced 

 bryologists make a liberal use of the hand-lens, while beginners are much more 

 dependent upon the compound microscope. All who would become familiar 

 with the mosses are indebted to the author for the clear presentation of those 

 characters which will enable one to recognize so many forms in the field without 

 the necessity of bringing them to the laboratory and making mounts for the com- 

 pound microscope. However, it is very probable that a student who uses this 

 little book will soon find his interest increasing and will be led to use the more 

 extended and technical works which would never have attracted him at the 

 beginning. c. j. c. 



Campbell, D. H. The Embryo-sac of Peperomia. In this, his third paper on Peperomia, 



Annals of Botany. 15: lovuS, pi. 6, iqoi. ,, ., , , , ., ^ 



^ J r :r |.jjg writer acknowledges that some of 



his previous interpretations must be abandoned and that Johnson's results are 

 substantially correct. It will be remembered, however, that Johnson confirmed 

 the most important point in Dr. Campbell's preliminary paper, namely, that there 

 are sixteen nuclei in the embryo-sac instead of eight, the usual number in angio- 

 sperms. The principal results of the present work are as follows : All species 

 of Peperomia seem to agree in having sixteen nuclei in the embryo-sac, and there 

 is no polarity as in other angiosperms. The Q.gg cell is somewhat differentiated 

 by an accumulation of cytoplasm about it, but there are no well marked syner- 

 gids. Several (usually eight) nuclei fuse to form the endosperm nucleus. 

 These are regarded as homologues of the polar nuclei of typical angiosperms. 

 One of the male nuclei from the pollen tube fuses with the egg nucleus, but the 

 fate of the other male nucleus could not be determined. The embryo is small 

 and shows no differentiation into organs when the seed is ripe. The divisions 

 of the endosperm nuclei are always accompanied by the formation of cell 

 walls. 



The writer still believes that the embryo-sac of Peperomia represents a primi- 

 tive condition and that the presence of sixteen nuclei is not a derived feature. 



