•ees 



SCIENCE 



[N. S. Vol. XXIX. No. 747 



"tures being devoted almost exclusively to fer- 

 mentation and the actions of enzymes external 

 to the cell and not intra-cellular activities. 

 The cytologist looks here in vain for informa- 

 tion regarding constructive and destructive 

 metabolism, oxidation, etc., in the cell. He 

 finds, however, an excellent and clear exposi- 

 tion of the kinds of ferments and of their 

 importance in digestion in animals and plants, 

 and in the first lecture of this second set he 

 finds a most excellent illustration of the cost 

 in labor of ascertaining a single scientific fact, 

 a concise history of the development during 

 the last two hundred years of our knowledge 

 ■of fermentation being given. The third sec- 

 tion of three lectures entitled Eecent Methods 

 and Results in Biological Inquiry, and the 

 last section of four lectures on Toxins and 

 Antitoxins, contain much repetition of the 

 ■earlier lectures, but we find here a valuable 

 •elaboration of the lines of research in a field 

 where Dr. Macfadyen was familiar with every 

 inch of the ground. Here is an excellent 

 summary of the effects of microorganisms as 

 agents of disease and of inununity to and 

 prevention of disease, all as understood at the 

 time the lectures were written and well serv- 

 ing as a basis for those who would study the 

 modern developments of these importaait lines 

 of biological research. 



G. N. 0. 



SCIENTIFIC JOURNALS AND ARTICLES 

 The Journal of Experimental Zoology, Vol. 

 VI., No. 2 (February, 1909), contains the 

 following papers : " Studies on Chromosomes, 

 v.. The Chromosome-groups of Metapodius, 

 A Contribution to the Hypothesis of the 

 Genetic Continuity of the Chromosomes," by 

 Edmund B. Wilson. This contains a detailed 

 account of the " supernumerary chromo- 

 somes," which form a specific class and vary 

 in number in different individuals of the same 

 species. The facts are shown to form a strong 

 support to the general theory of the genetic 

 continuity of the chromosomes, of which a 

 general discussion is given. " The Effects of 

 Desiccation on the Eotifer, Philodina roseola," 

 by Merkel Henry Jacobs. The old question 

 of the possibility of revival of rotifers after a 



more or less protracted desiccation is again 

 taken up, and as a result of numerous experi- 

 ments the older view that recovery is possible 

 after a true desiccation is confirmed and the 

 newer one that the animal at the time of dry- 

 ing is protected by a water-proof cyst is shown 

 to be based on insufficient evidence. In addi- 

 tion, it is shown that the process of drying 

 serves as a stimulus to reproductive activity, 

 a definite relation existing between the periods 

 of drying and those of egg laying. "Proto- 

 zoan Studies," by J. E. McClendon. Amcebae 

 do not respond to minutely localized mechan- 

 ical stimulation unless this be repeated at 

 short intervals of time. By chemical stimula- 

 tion it was found that the stimulus traveled 

 through the Amceha at a rate probably faster 

 than the movement of the fastest ions in aque- 

 ous solution. The movement of this stimulus 

 might be compared to the nervous impulse, 

 save that not being confined to a nerve fiber 

 it spreads in all directions. Experiments sug- 

 gested the following hypothesis of food taking 

 by the Amoela: External chemical and phys- 

 ical processes cause a hardening and shrinking 

 of the surface protoplasm, thus forming the 

 ectosarc. Internal processes cause a liquefy- 

 ing of the protoplasm, thus forming the endo- 

 sarc. Unstable equilibrium between these two 

 sets of processes causes amoeboid movements. 

 A protoplasmic food body near the Ameeha 

 protects it locally from external processes and 

 thus causes the Amosha to bulge out toward 

 the food. That spot on the Amceha that 

 touches the food is stimulated, hardens and 

 ceases to advance. Therefore lateral pseudo- 

 podia are formed and surround the food. 

 Paramecia were centrifuged for periods of 

 time up to one week. The nuclei, chromatin 

 and other heavy substances were precipitated, 

 but returned to their normal positions in 

 about the length of time during which they 

 had been centrifuged. The negative geo- 

 tropism returned simultaneously with return 

 of these substances. Centrifuging stimulated 

 division. Centrifuging produced abnormali- 

 ties and these were not transmitted to both 

 products of binary fission. Paramecium 

 aurelia formed membranous cysts and while 

 in them often absorbed its own anterior or 



