1426 Journal of Applied Microscopy 



discussion of the different phases of the subjects treated. Considering the space 

 at the authors' disposal, this end is very well attained. 



The first of the two books is a discussion of all the so-called irritable phe- 

 nomena displayed by the living organism. After a brief but excellent intro- 

 ductory historical chapter, the morphology and chemical composition of living 

 matter are treated in a very general way. A chapter is then given to the 

 discussion of the external conditions, such as oxygen supply, heat, nutriment, etc., 

 necessary for the performance of vital functions. Under the caption 

 "Nutritive Irritability " the process of digestion is described, particular attention 

 being given to the action of the different ferments. Under "Functional Irritability" 

 are treated the subjects of animal heat, the phenomena of movement, including 

 the various " taxes " and " tropisms,'' animal electricity and phosphorescence. 

 Considerable space is devoted to the functions and activities of the nervous 

 system, the subject being introduced by a somewhat doubtful comparison of the 

 nucleus of the cell to the central nervous system. A section is given to the 

 phylogenetic development of the nervous system. The final chapter takes up 

 briefly the nature of irritability in general, from the standpoint of the chemical 

 relations of protoplasm. 



The other book, "L'Orientation," is psychological, both in point of view and 

 treatment. Its purpose is to show how an organism's notions of its relations in 

 space are developed. The term " orientation " is used throughout in this general 

 sense of " space relation,'' rather than in the more ordinary restricted physiolog- 

 ical sense of a particular sort of a reaction to certain stimuli. Such subjects as 

 the muscle sense, the senses of active and passive movement, equilibrium, and 

 tactile, visual and auditory space localization are discussed, among others. A 

 chapter is devoted to the migratory and homing instincts of birds. These the 

 author explains (?) as due to heredity and a well developed sense of direction. 



R. p. 



Levene, P. A. This series of papers, while dealing 



I On the Nucleoproteids of the Brain, ^^j^i^ technical matters in the subject of 

 Arch. Neurol, and Psychopathol. V. II, p. 



1-14, 1899. physiological chemistry, are, on account 



II. Iodine Compounds in the Tissues after of ^heir breadth of view and clear 

 Administration of Potassium Iodide. Ibid, p. 



15-20, 1899. method of presentation, of considerable 



III. On the Absorption of Proteids (with interest to the biological reader. The 

 I. Levin). Ibid, p. 551-556, 1899. ° 



IV. Embryochemical Studies. Ibid, p. 557- first paper of the series discusses the 



5^5> 'S99. . , „ , . , . . ^ „ . , chemical nature of the nucleoproteid 



V. 1 he Chemical Relationship of Colloid, 



Mucoid and Amyloid Substances. Ibid, p. 571- or chromatin of the brain. Extracts of 



573. 1899. ^Y^Q brains from freshlv killed calves 



(Reprints dated 1900.) 



were used. The nucleocompound ob- 

 tained by this extraction was found to be a true nucleoproteid, differing from 

 other nucleoproteids by its low percentage of phosphorous, by the nature of its 

 xanthin bases, and by the large amount of proteids bound to its nuclein. There 

 does not seem to be any evidence of more than one nucleoproteid in the brain, 

 but on the contrary it seems probable that the chromatin of the cytoplasm (in 

 the Nissl's granules of the ganglion cells) does not differ chemically from that of 

 the nucleus. 



