3 8o 



THE GUIDE TO NATURE 



gellate and other Protozoa and the inter- 

 esting wheel animalcules (Rotatoria). 



To intelligently study these lowly 

 creatures of pond, river, and brook it is 



wttiich were made especially for this 

 volume, render this book an indispen- 

 sable addition to the shelves of all biolo- 

 gists and also of those who use the mi- 

 croscope for the less serious but none the 

 less interesting recreation of studying 

 these small creatures of the water. 



THE PLANARIA, AN INTERESTING FLAT 

 WORM AMONG THE WATER PLANTS. 



necessary to have at hand a manual that 

 will describe and figure the commoner 

 and more abundant species that we are 

 likely to find in our rambles about the 

 country. For this purpose no work has 

 been better prepared than the recently 

 published volume by Ward and Whippel 

 entitled "Fresh-water Biology."* Un- 

 like most manuals of this subject the 

 present volume is the result of the la- 

 bors of a goodly number of America's 

 leading biologists and specialists, no less 

 than twenty-five individuals having con- 

 tributed to its pages. In this day of 

 specialization it is manifestly impossible 

 for a single biologist to cover in a satis- 

 factory or reliable manner the Whole 

 field of biological science, and realizing 

 this limitation the authors of this admir- 

 able volume have enlisted the foremost 

 students of the various groups of animals 

 and we thus have in one book an authori- 

 tative treatise on each of the great divis- 

 ions of the subject. The manv descrip- 

 tions of habitat relations (Ecology), of 

 the best means for collecting and preserv- 



SOME OF THE COMMON FORMS OF WATER 

 SNAILS. 



ing the animals for temporary or per- 

 manent examination, and the vast num- 

 ber of good illustrations, the majority of 



*Fresh-water Biology. By Henry Bald- 

 win Ward and George Chandler Whippel. 

 John Wiley and Sons, 1918. 1111 pages 

 and 1547 illustrations. 



An Efficient Laboratory. 



The Biological Laboratory at Cold 

 Spring Harbor, Long Island, has is- 

 sued its announcement for the summer 

 of 1918, its twenty-ninth season. The 

 laboratory offers commendable courses 

 of instruction in the study of four-foot- 

 ed animals, birds, microscopic life, in- 

 sects, etc. While the work in the main 

 contemplates serious technical results, 

 it is equally well adapted to the teacher 

 of biology and to the high school stu- 

 dent. We cordially recommend the 

 laboratory. If our readers will write, 

 mentioning this magazine, a pamphlet 

 giving particulars will be sent. Ad- 

 dress Dr. Charles B. Davenport, Cold 

 Spring Harbor. Long Island, New r 

 York. 



Some workers with the microscope 

 have for a long time been marking their 

 slides by writing directly on the glass 

 with a waterproof ink or with a dia- 

 mond. The latest wrinkle is to use a 

 sharp crystal or carborundum laid be- 

 tween the two halves of a piece of elder 

 pith, the whole wound tightly with a 

 rubber band. 



Grasses, trees, shrubs, growing 

 grain, they, too, may need good air as 

 well as human lungs. The deserts are 

 not worthless wastes. You cannot 

 crop all creation with wheat and al- 

 falfa. Some sections must lie fallow 

 that other sections may produce. Who 

 shall say that the preternatural produc- 

 tiveness of California is not due to the 

 warm air of its surrounding deserts? 

 Does anyone doubt that the healthful- 

 ness of the countries lying west of the 

 Mississippi may be traced directly to 

 the dry air and heat of the deserts. 

 They furnish health to the human ; 

 why not strength to the plant? The 

 deserts should never be reclaimed. 

 They are the breathing-spaces of the 

 west and should be preserved forever. 

 -John C. VanDyke in "The Desert." 



