Miscellaneous Intelligence. 401 



tion, namely, the lack of water on the Moon. While it is true 

 that water cannot exist in the free state under a pressure that is 

 less than 4*6 millimeters, and while it is also true that no such 

 pressure apparently exists upon the Moon's surface, still there is 

 nothing to prevent water occurring beneath the surface of the 

 ground, retained by the capillary action of the soil. It has been 

 shown by Cameron (Science, 1903, xviii, 758) that water can be 

 extracted by dry soil from a membrane against a calculated 

 osmotic pressure of 36 atmospheres, or about 500 pounds per 

 square inch. Since on the Earth plants can live on moisture 

 which they have in turn extracted from such a soil, there seems 

 no difficulty in understanding how they could live on the Moon, 

 in a soil which could thus retain considerable moisture in spite 

 of the low atmospheric pressure. Indeed if it were possible to 

 conceive of an organism which could absorb its oxygen directly 

 from vegetation, and store it during the lunar night, there is no 

 reason why animal life should be impossible upon the Moon. 



That the substance which we have called vegetation is fre- 

 quently found in connection with deep clefts has already been 

 pointed out by the author, in dealing with the crater Franklin, 

 see "The Moon," page 56. That a dark patch of vegetation 

 sometimes covers an area formerly occupied by ice has been 

 shown in the case of Riccioli in the Harvard Annals, xxxii, 216. 

 Finally, that different areas of vegetation in the same crater may 

 appear and disappear at quite different times has been pointed 

 out in the case of Alphonsus, in the Annals, xxxii, 33. It there- 

 fore appears that the various phenomena above described have 

 all been indicated before in visual observations made at this 

 Observatory. Their interest here lies chiefly in the fact that in 

 Eratosthenes they are shown so clearly, and upon so large a scale, 

 that we are now able to photograph them. We are thus able to 

 share with other astronomers what in the case of visual observa- 

 tions can only be seen by those who have good enough atmos- 

 pheric conditions to be able to detect them. In the case of visual 

 observations other persons must place their faith on the judg- 

 ment and accuracy of the observer, in the present case the photo- 

 graphs permit every reader to be his own observer and judge." 



3. Field Columbian Museum, Publication 95, Zoological Series, 

 vol. IV, parts I and II, pp. xx, 850, with sixty-eight plates and 

 numerous text-figures. — These volumes are devoted to the "Land 

 and Sea Mammals of Middle America and the West Indies," by 

 Daniel Girattd Elliot. This admirable work follows the 

 "Synopsis of the Mammals of North America and Adjacent Seas" 

 by the same author and is intended to contain all the mammals of 

 the remainder of the North American Continent, that is from the 

 northern boundary of Mexico to the Province of Cauca, South 

 America, including the coast islands, also part of Bahamas and 

 West Indies. It is clearly presented and very fully illustrated. 



4. Statistical Methods with special reference to Biological 

 Variation ; by C. B. Davenport. Second, revised edition, pp. 



Am. Jour. Sci. — Fourth Series, Vol. XVIII, No. 107. — November, 1904. 

 27 



