368 



SCIENCE. 



[N. S. Vol. III. No. 62. 



there the matter ends, save under the head of 

 bibliography for geographical distribution, 

 where the list of nine, not all American, begins 

 with Schweinitz and includes Berkeley, Curtis, 

 Ellis and Peck. It is noted that Dr. Burrell is 

 credited with first discovering a plant disease 

 of bacterial origin; namely, ' the shrivelling o 

 pears ' in 1880 due to Micrococcus amylovorus. 



The total number of described species of 

 fungi is given as 40,000, an estimate founded 

 upon the Sylloge of Dr. Saccardo. 



Under the chapter upon geographical distri- 

 bution it is stated that the fungi are not yet 

 well enough known to more than conjecture 

 as to their distribution on the earth. China is 

 still an unknown laud and India but little 

 better, and Africa is a ' dark continent ' so far 

 as fungi are concerned. The fleshy fungi are 

 mostly in the temperate regions. Nearly the 

 whole of the Amaniteas groups of exceedingly 

 poisonous toadstools are rarely met with in the 

 tropics. 



Under classification some of the salient points 

 are introduced, as naked and covered spores, 

 perfect and imperfect forms and the character 

 of the spore covering. While not accepting the 

 classification offered by Brefeld in full, Dr. 

 Cooke recognizes its influence and summarizes 

 it in tabulated form. In the same chapter a 

 page and a half is given to the drawing of lines 

 of contrast between lichens and fungi, and the 

 first page of the introductory chapter states, 

 " It is now known that aquatic fungi are not 

 an impossibility, that algte may grow in damp 

 atmosphere and that some portions of the sub- 

 stance of lichens may be derived from their 

 matrix." From these statements the student 

 would gain no encouragement to incline toward 

 the modern theory of the fungo-algal conception 

 of lichens. 



The book is printed upon unusually heavy 

 paper with uncut edges and weighs about three 

 pounds. Half the size and bulk would make 

 it many times more companionable. 



"While the faults have been most largely 

 pointed out, the book cannot but be useful and 

 aid the collector to reach the conclusion ex- 

 pressed in the last sentence of the work : " The 

 whole history of one species worked out with 

 perseverance and intelligence will present the 



key to a knowledge of many kindred species 

 and always prove to be a valuable contribution 

 to science when the names of species are 

 changed or forgotten." When this fact is real- 

 ized in the collector he becomes a working 

 factor in the strict sense for the advancement 

 of his science. Byron D. Halsted. 



A Preliminary Report on the Geology of South 

 Dakota. By J. E. Todd. South Dakota 

 Geological Survey. Bulletin No. I. Sioux 

 Falls, South Dakota. 1895. Pp. viii, 172. 

 Plates v., figures 2, and preliminary geologic 

 map of South Dakota. 



In the above report Prof. Todd, who is the 

 State Geologist, has summarized what is known 

 of the geology of South Dakota. The author's 

 studies of the geology of this State began in 

 1881, since which time his connection with the 

 United States and State Surveys has enabled 

 him to examine in the field most of the geologi- 

 cal formations found in South Dakota. The 

 work is written in popular form in order that it 

 may serve as a geological guide to the citizens 

 of the State; but in its pages is also found matter 

 of value to the teacher and geologist. 



The report contains a chapter devoted to each 

 of the following topics : Introduction, topogra- 

 phic features, sketch of the geology of the State, 

 eruptive rocks, geological history of South Da- 

 kota, and economic geology, while the descrip- 

 tion of the geological formations of the State 

 occupies four chapters, making ten in all. Prof. 

 Todd finds that the following systems are repre- 

 sented : Huronian, Cambrian, Lower Silurian, 

 Carboniferous, Triassic, Jurassic, Cretaceous, 

 Tertiary and Quaternary, while 25 feet of shales 

 in the vicinity of Deadwood is referred doubt- 

 fully to the Devonian. On consulting the geo- 

 logic map it will be seen that about two-thirds 

 of the State is covered by formations belonging 

 to the Cretaceous system, of which the Colorado 

 group is first in area and the Laramie second. 

 After the Cretaceous system the Miocene of the 

 Tertiary is second in areal extent, and the 

 Huronian third. 



Among minerals of economic value, gold is 

 the most important, the Black Hills in 1893 pro- 

 ducing $4,000,000. The author says that the 

 oxide of tin (cassiterite) ' occurs very generally 



