Apeil 4, 1902.] 



SCIENCE. 



541 



understanding of the subject in which he is 

 interested. 



The author might have gone farther in 

 stating that many publications supposedly 

 written in a popular manner — at least 

 designed for distribution among the agricul- 

 tural population — are so filled with technical 

 terms as to render them unintelligible to the 

 average reader. Many of the writers who pub- 

 lish in this manner fail to furnish summary 

 accounts of what has been given in detail, 

 and thus the reader is obliged to peruse many 

 pages which have no interest to him in order 

 to secure the object desired, which is usually 

 an approximate knowledge of the appearance 

 of the insect, the nature of its ravages, life- 

 history, and, above all, the means for its 

 reduction. 



It might have been added that every year 

 brings new pests to our shores, which in time 

 become disseminated by flight and commerce 

 through our country, and that this necessi- 

 tates the. publication of new popular works or 

 of new editions of the old in order to consider 

 these foreign pests and bring the works up 

 to date. 



In estimating the money value of the injury 

 done by insects the author states that when 

 we include that done to fruits, truck 

 crops,' domestic animals and timber, $300,000,- 

 000 is a conservative estimate of the price 

 these apparently insignificant creatures an- 

 nually cost this country. 



One good feature of the author's treatment 

 of his subjects consists in the space given to 

 the consideration of general farm practices 

 that may be used in combating insect pests. 

 In the treatment of this chapter he points 

 out that few farmers in planning the manage- 

 ment of their land for crops for the season 

 consider the eilect which any given procedure 

 will have upon injurious insects with which 

 they may have to contend. Farmers too fre- 

 quently fail to look far ahead, and rotation 

 of crops when practiced is more for the sake 

 of soil improvement than for the reduction 

 of insect attack, and yet crop rotation is the 

 only remedy for many species of insects when 

 they occur in injurious numbers over large 

 areas, e. g., in fields of grain. Among other 



methods of tillage, clean farming, the destruc- 

 tion of weeds that might harbor injurious 

 species, the burning over of fields after the 

 crops have been made, fall plowing, drainage, 

 the judicious use of fertilizers, the employ- 

 ment of trap crops, and the selection of the 

 proper time for planting, are considered. Due 

 attention is also given to the structure and 

 development of insects, to beneficial insects, 

 the value which accrues from the use of poul- 

 try as insect exterminators, and to insecti- 

 cides, and the means for preparing and apply- 

 ing them. 



Professor Sanderson's work is well fitted 

 for the class of persons whom it is designed 

 to reach, and it should have a large sale. 



F. H. Chittenden. 



SCIENTIFIC JOURNALS AND ARTICLES. 



The Journal of Comparative Neurology for 

 March contains two papers by J. E. Johnston 

 on 'The Brain of Petromyzon/ and the 

 'Primitive Functional Divisions of the Nerv- 

 ous System.' The structure and connections 

 of the nuclei of the cranial nerves in Petro- 

 myzon are closely similar to those of Acipen- 

 ser previously described by the same author. 

 Especially noteworthy is the presence of a 

 large post-auditory lateral line root and a 

 lobus linese lateralis corresponding to that of 

 selachians and Acipenser. The fasciculus 

 communis root of the facialis and the central 

 relations of the sensory IX. and X. nerves are 

 recognized and described for the first time. 

 The cerebellum is in a very primitive condi- 

 tion histologically, the Purkinje cells being 

 represented by simple large cells similar to 

 th'ose of the acusticum. In the forebrain the 

 illusion of a well-developed cortex is due to 

 the crowding and telescoping of the parts by 

 pressure from the upper lip. The nuclei and 

 fiber tracts are shown to be strictly compara- 

 ble to those of the brain of other fishes. There 

 is no cortex. The olfactory lobe contains a 

 large number of slightly differentiated cells 

 which serve as the end-nucleus of the olfactory 

 nerve. In the second paper the author defines 

 the longitudinal zones of the spinal cord and 

 brain and the peripheral components and end- 

 organs related to each. 



