756 



SCIENCE. 



[N. S. Vol. XXI. No. 541. 



tion.' Sue devotes a dozen or so pages to a 

 brief historical sketch and several pages to 

 the methods of coEecting, fixing, sectioning 

 and staining which she followed, and then 

 takes up in successive chapters, ' Microsporo- 

 genesis,' ' The Male Gametophyte,' ' Macro- 

 sporogenesis,' ' The Female Gametophyte,' 

 ' Fertilization and Eelated Phenomena.' In a 

 short appendix the author has recorded a num- 

 ber of interesting and suggestive abnormal 

 conditions which have been noticed by her and 

 other observers. A full list of papers cited 

 closes the text of this altogether admirable 

 paper. The plates number twenty-four and 

 include 275 well executed figures. 



The work upon which the paper was based 

 was begun in the fall of 1897. The discoveries 

 of Hirase, Ikeno and Webber in the fertiliza- 

 tion of the gymnosperms made it ' highly de- 

 sirable that fertilization and the associated 

 phenomena should be worked out for other 

 members of this group by the more modern 

 methods of investigation.' This was the task 

 which Miss Ferguson set for herself, and in 

 this paper she has recorded the results of her 

 investigation of five species of pines (Pinus 

 strobus, P. rigida, P. austriaca, P. montana 

 uncinata and P. resinosa). Six hundred 

 separate collections of material were made, 

 and more than four thousand slides of serial 

 sections prepared. This large number is 

 necessary since in the pines a period of almost 

 thirteen months elapses from pollination to 

 the actual fertilization, during which many 

 important cytological changes take place. 



We have space to note here only a few 

 things brought out in this pajier: The author 

 makes a distinction between the microspore 

 (one-celled) and the pollen-grain (several- 

 celled), the former developing into the latter 

 by a series of divisions. In tracing the de- 

 velopment of the sperm-nuclei (spermatozoids) 

 Miss Ferguson finds what she suggests may be 

 the vestigial state of the cilia-forming body 

 found in the lower gymnosperms (Cycas, 

 Zamia and Ginkgo). In the development of 

 the macrospore the division of the mother cell 

 is a true tetrad division, so that the macrospore 

 is a true spore. This germinates and by a 

 typic division gives rise to two nuclei which 



pass to opposite poles and there divide again 

 and again until thirty-two or more free nuclei 

 are formed before the long winter rest is 

 entered upon. The prothallium is completed 

 and the archegones (one to nine) are formed 

 the next spring. In fertilization the sperm 

 and egg-cell cytoplasms fuse, but the nuclei 

 do not really fuse, but the chromosomes are 

 mingled in the first mitosis. 



LIMU. 



This is the name applied to many species of 

 seaweeds, especially those that are edible, by 

 the native Hawaiians. In a recent number 

 of the ' Publications ' of the University of 

 California (Vol. III., No. 3) Professor Dr. 

 Setchell gives the results of the investigations 

 made by him several years ago, with a view 

 to determining the specific identity of the 

 different kinds of limu. Altogether his list 

 includes one hundred and seven names, not, 

 however, representing that many distinct 

 kinds. For many of these he has been able 

 to determine the species used, while in other 

 cases this has not been possible. One is sur- 

 prised at the considerable number of species 

 of seaweeds which the islanders have found 

 to be edible, although one suspects that many 

 of them would not be relished by us. 



A NEW GRASS BOOK. 



Ai.THOUGH not strictly botanical the little 

 book entitled ' Farm Grasses of the United 

 States,' by Professor Spillman (Orange Judd 

 Co.), is worthy of a brief notice in these 

 columns. In it the author, who as is well 

 known, is the chief of the Division of 

 Agrostology of the United States Department 

 of Agriculture, has brought together a good 

 many facts that are of interest to the farmers 

 of the country, and some also that will inter- 

 est the general botanist. Thus the map on 

 page 13 showing the relative amounts of wild, 

 salt and marsh grasses annually cut for hay 

 in different parts of the United States will in- 

 terest every botanist, and so will the chapter 

 on ' The Seed' (V.). So too the botanist will 

 find something of interest in the succeed- 

 ing chapters (VI. to XIII.) which discuss 

 timothy, the blue-grasses, the millets, two 



