Miscellaneous Intelligence. 89 



8. Lehrhuch der Okologischen PfloMzen-geograjohie, von Dr. 

 EuGEN Warmi:^g. Berlin, 1896, pp. 412. — Professor Warming, 

 of Copenhagen, has presented in this interesting work some of 

 the more important facts regarding the relations of plants to their 

 surroundings. The adaptations of vegetation are classified in a 

 simple manner which gives the impression of an exhaustive sys- 

 tem. All the factors are considered in turn and the response of 

 plants to all external influences is stated clearly. Mutual rela- 

 tions of plants and animals are taken up in a very attractive and 

 thorough fashion, and without any attempt at exaggeration. The 

 biological associates are proj)erly grouped and described, and, 

 lastly, the struggle between these groups is dealt with in a 

 graphic style. This contribution to geographical botany merits 

 an early and good translation into the English language. 



G. L. G. 



9. Missouri Botanical Garden. Seventh Annual Report. 

 St. Louis, Mo., 1896, pp. 209. — Professor Teelease gives a val- 

 uable monograph on the Juglandacese of the United States in 

 which he has tabulated characters presented by the fruit, twigs, 

 bark, and buds. He states that, owing to the publication of the 

 seventh volume of Professor Sargent's Silva of North America, 

 he does not consider it desirable to publish the entire manuscript 

 he had prepared. Even in its abbreviated form it is a very 

 important addition to the literature of the subject. It is charac- 

 terized throughout by the excellent qualities which mark all of- 

 Professor Trelease's work. 



From Miss Mulford we have a careful study of the Agaves of 

 the United States. The histological and economic aspects of 

 these plants have received much attention from her, and are here 

 clearly described. 



Mr. C. H. Thompson treats of the ligulate Wolffias of the United 

 States. 



The Director presents an interesting account of the pre-Linnoean 

 library presented to the Garden by Dr. E. Lewis Sturtevant of 

 Massachusetts. This exceedingly valuable library will be of the 

 greatest use in the researches in regard to cultivated plants which 

 are prosecuted under Professor Trelease's direction. g. l. g. 



in. Miscellaneous Scientific Intelligence. 



1. The height of the luminous night-clouds. — The Observatory 

 at Berlin is about to publish the results of an elaborate investiga- 

 tion of the luminous night-clouds by Dr. Jesse. The author 

 gives in the Astronomische Nachrichten, No. 3347, some of the 

 principal results of lis observations and discussion. They are 

 based on photographs taken in the months of June and July in 

 the years 1889-91 at Steglitz, Berlin, Nauen and Ratheuau. A 

 striking peculiarity of the results is the almost constant altitude 

 of the clouds. Although the photographs were not strictly simul- 

 taneous, yet the computed heights of points in these clouds lie 

 between 80*27 and 88-53 kilometers, the mean height of the series 

 being 82-08. 



