376 



THE POPULAR SCIENCE MONTHLY, 



direction, producing results congeric with 

 itself; hence, in the world of mechanical 

 force, the series are complete, calculable, and 

 demonstrative. But, obviously, other modes 

 of activity are possible and probable to in- 

 telUgent will. When acting in the organic 

 instead of the mechanical world, though con- 

 forming still to a fundamental law of evo- 

 lution, its results may not present series 

 which shall be complete, calculable, and 

 demonstrative, but incomplete, contingent, 

 and suggestive. Such seems to be the char- 

 acter of the succession of animals an^ 

 plants. The series, as an evolution, lacks 

 its first terms ; it presents regressions ; it 

 yields to the demands of physical correla- 

 tions and ideal concepts ; it betrays every- 

 where the activity of a force whose law is 

 not that which dominates in the mechanical 

 world. 



" Mr. Spencer, in stating, in substance, 

 that the efficient cause of evolution is a 

 mode of the Unknowable, expresses our idea 

 exactly in relegating this efiFect to a Power 

 without the sphere of sensible things. But 

 we differ from Mr. Spencer, toto coelo, in re- 

 spect to his dogma of the Unknowable, hold- 

 ing that the causa causarum is revealed 

 qualitatively to every rational being. The 

 cause of evolution is therefore a mode or 

 volition of the incomprehensible Mind." 



Dr. Winchell's book will well repay peru- 

 sal to those who are interested in the litera- 

 ture of the subject; and the addition of 

 Barrande's ai'gument against Darwinism, in 

 the Appendix, will augment its value to sci- 

 entific students. 



Field Ornithology : Comprising a Manual 

 of Instruction for procuring, preparing, 

 and preserving Birds, and a Check List 

 of North American Birds. By Dr. El- 

 liot CouES. Salem Naturalist Agency, 

 1874. Price $2.50. 



The present work is a supplement to 

 Dr. Coues's admirable treatise entitled "Key 

 to North American Birds," published in 

 18*72, and contains matter originally intend- 

 ed for that volume, but which, owing to 

 lack of space, was left for future publica- 

 tion. The first half of the book consists 

 of eight chapters, in which the reader is 

 told in an easy, entertaining way how to 

 proceed in the collection, preparation, and 

 preservation of birds. As you must " first 



catch your hare," the author very appro- 

 priately devotes the opening chapter to the 

 subject of implements of capture, and, the 

 gun being the chief of these, minute direc- 

 tions for guidance in its selection, care, and 

 use, are given. A short chapter on the em- 

 ployment of the dog as an aid in collecting 

 comes next ; and is followed in Chapter III. 

 with directions for general field-work, such 

 as the time of year to make collections, the 

 manner of approaching birds, their recovery 

 after being wounded or killed, and how to 

 dispose them for carriage homeward. The 

 last section of this chapter, on " The Hygiene 

 of Collectorship," contains a good many 

 valuable suggestions that apply with equal 

 force outside the business of bird-collect- 

 ing. The fourth chapter deals with the 

 subject of notes and labeling; the fifth is 

 on instruments, materials, and fixtures, for 

 preparing bird-skins ; the sixth contains 

 directions for skinning, and the prepara- 

 tion of skins ; and the seventh treats of 

 miscellaneous matters, such as the deter- 

 mination of sex and age, the study of osteo- 

 logical characters, and the collection and 

 preservation of eggs and nests. The last 

 chapter is on the care of a collection, and 

 gives directions for the construction of 

 cabinets, and the exclusion of insect pests. 

 Drawn from the writer's own experience, 

 which has been most varied and extensive, 

 these instructions cannot fail to be of great 

 use to those proposing the study of birds 

 at first hand. 



The second part of the book consists of 

 a check-list of North American birds, in- 

 tended to replace the one now in use, which, 

 owing to the rapid advance of the science of 

 ornithology, has become defective in many 

 ways. A notable feature of the new list is 

 the reduction of the number of genera, and 

 especially of the number of species given in 

 the old one, in accordance with the grow- 

 ing conviction that naturalists long ago got 

 ahead of Nature in the formation of specific 

 distinctions. 



Proceedings of the Georgia Teachers' 

 Association. 



It is an encouraging sign to the friends 

 of progress that school-teachers are awak- 

 ening to the necessity of scientific educa- 

 tion. At the seventh annual meeting of 



