500 



SCIENCE 



[N. S. Vol. XXV. No. 639 



undeniable facts of accurate observation. 

 The rest of the summary is devoted to show- 

 ing hovr these articles dove-tail together in 

 mutual confirmation. 



Part II. describes what the author calls 

 ' Non-natural Features,' by which he means 

 those which have the least analogy to features 

 on the earth, and which differ most from what 

 our terrestrial experience would lead us most 

 naturally to expect. In this category he 

 places the canals, and describes their system 

 and their gemination, and presents arguments 

 to substantiate their objectivity as opposed to 

 the diplopic, or the interference, or the illu- 

 sion theory. A full - account of the double 

 canals is given, also of the canals in the dark 

 regions, of the oases, of the ' carets ' on the 

 ■borders of the great diaphragm ; and a descrip- 

 tion of Lampland's success in photographing 

 thirty-eight canals, the doubling of Nilokeras 

 and a snovrf all, together with the more promi- 

 nent ' continents,' ' seas ' and ' oases.' 



Part III. deals with the ' Canals in Action,' 

 under the headings Canals: kinematic. Canal 

 Development Individually Instanced, Hiberna- 

 tion of the Canals, Arctic Canals and Polar 

 Eifts, Oases : kinematic. The purpose of this 

 section and also of Part IV. is to show that 

 the canals are real water arteries for the dis- 

 tribution of the melting polar caps to the arid 

 equatorial regions, and to the constitution 

 and purpose of the canals and oases in this 

 scheme, with arguments in support of the 

 hypothesis that life, sentient and vegetable, 

 does exist on Mars. 



The book is copiously illustrated, and closes 

 with an index of nine pages. 



Herman S. Davis 



SOCIETIES AND ACADEMIES 

 THE TOEREY BOTANICAL CLUB 



The second stated meeting for the year 

 1907 was called to oi'dter at the Museum 

 Building of the New York Botanical Garden 

 at 3 :30 o'clock p.m. on January 30, 190Y, with 

 Vice-president Professor L. M. Underwood in 

 the chair. Twenty-three persons were present. 



The scientific program was as follows: 



Experiences on the Island of Jamaica during 



the Earthqualee of January IJf, 1907: Dr. 



M. A. Howe. 



A trip for the collection and study of 

 marine algse and other plants brought Dr. 

 Howe to the island of Jamaica on December 

 14, and he was on the island during the recent 

 earthquake. An interesting account was 

 given of his experiences at that time 

 New or Bare Mosses from Jamaica: Mrs. N. 



L. Britton. 



Mrs. Britton exhibited some of the most 

 interesting mosses collected in Jamaica, show- 

 ing several genera and subgenera, not hereto- 

 fore known in the West Indies, and several 

 new species, and also indicated some reduc- 

 tions of names to synonyms. Specimens of 

 types of Jamaican species were also shown 

 from the Mitten Herbarium and one of Miss 

 Taylor's drawings of a new species and sub- 

 genus. 

 The Prohahle Function of Tannin in Galls: 



Dr. Melville T. Cook. 



The origin, chemistry and uses of tannin 

 have been studied very extensively, but other 

 phases of the subject have received compara- 

 tively little attention. This is especially true 

 concerning the functions which it serves in 

 the plant. It is usually very abundant in 

 diseased tissues, such as insect galls, fungus 

 galls, fungus spots, etc. In insect galls it is 

 developed very early and in some cases it ap- 

 pears to result in the gall-makers moving to 

 other parts of the plant. It is also formed in 

 fungus-galls, frequently completely surround- 

 ing the point of rupture. In such fungus 

 spots as those produced by Cercospora the suc- 

 cessive circles are due to the depositing of 

 tannin within the tissues. The author has 

 made extensive studies on the anatomy of 

 both insect and fungus galls and is now con- 

 ducting a series of physiological experiments. 

 C. Stuart Gager, 



Secretary 



SPECIAL ARTICLES 



THE limitations OF ISOLATION IN THE ORIGIN 



OF SPECIES 



Any adequate consideration of the bearing 

 of the geographical distribution of organisms 



