August 18, 1911] 



SCIENCE 



215 



This memoir — confined to a discussion of 

 the anatomical characters, especially the struc- 

 ture of the gills, and to an arrangement of 

 the different groups in conformity with the 

 data newly obtained or now correlated by Dr. 

 Ortmann — comprises an important advance 

 in our knowledge of the fresh-water mussels. 

 Giving full credit to Lea and Simpson, pio- 

 neers in the classification of these animals 

 on the basis of the characteristics of the re- 

 productive organs and marsupium, the au- 

 thor's studies of the microscopic structure of 

 these organs have enabled him to rectify some 

 errors and add very largely to the available 

 data. The details are well illustrated both by 

 text figures and excellent plates. The descrip- 

 tion and illustration of the Pennsylvanian 

 species is reserved for future publication. 



Dr. Ortmann, on account of certain archaic 

 features, proposes for Magaritana a separate 

 family, retaining the other Pennsylvanian 

 forms in the Unionidae which he divides into 

 three subfamilies. He proposes a new genus 

 Paraptera for Lampsilis gracilis (Barnes) on 

 account of peculiarities of the glochidia. We 

 note that he adopts for the group commonly 

 known as Glaharis the name of Anodontites 

 which was first applied by Bruguiere. This 

 name is undoubtedly prior to any other for 

 the group in question, but by the rules in 

 vogue, at the time it was proposed the termi- 

 nation ites was reserved for fossil species, and 

 it was therefore not adopted. If Anodontites 

 be rejected Patularia Swainson precedes 

 Olabaris in date. 



Wm. H. Dall 



possessed of wide experience. Some of the 

 conclusions arrived at will be startling to 

 those unfamiliar with the general trend of 

 modern thought, but none are put forward 

 that are not logically in sequence to the evi- 

 dence presented. It will be difficult to secure 

 general acceptance of such conclusions as this 

 (p. 28) : " While municipal improvements, 

 such as the above " (cleaning of streets, back 

 alleys, etc., regulation of offensive trades and 

 prevention of nuisances generally), " are ad- 

 visable, there is little more real reason why 

 health officials should work for them, than 

 there is that they should work for free trans- 

 fers, cheaper commutation tickets — all good 

 things in their way and tending towards com- 

 fort and health." Yet the author brings for- 

 ward apparently good evidence to show that 

 such statements are warranted. Perhaps the 

 most valuable chapter is the second — in which 

 stress is laid upon " carriers and missed cases " 

 as most important sources of infection. At- 

 tention is called to the great influence of in- 

 fection by contact — the comparative slight 

 importance of infection by fomites or by air; 

 instances are given of the favorable results 

 following the abandonment of disinfection in 

 certain of the infectious diseases in Provi- 

 dence, and a proper amount of stress is laid 

 upon the transmission of certain diseases by 

 insects. For all who are interested in these 

 subjects the book will be a valuable aid in 

 recognizing the present evidence upon which 

 the control of infectious diseases must rest. 



Harold C. Ernst 



Habvakd Medical School 



The Sources and Modes of Infection. By 

 Charles V. Chapin, M.D., Sc.D., Superin- 

 tendent on Health, Providence, E. I., au- 

 thor of Municipal Sanitation in the United 

 States. New York, John Wiley and Sons; 

 London, Chapman and Hall, Limited. Oc- 

 tavo. Pp. ix + 399. 1910. 

 Any book written by this author is worthy 

 of attention, and this one especially so — ^for 

 in it is contained a summary of our knowledge 

 of the subjects of which it treats and the in- 

 terpretation put upon this knowledge by one 



BOTANICAL NOTES 

 A READABLE BOOK 



Among the most readable of recent botan- 

 ical books is that on " The Evolution of 

 Plants," by President D. H. Scott, of the 

 Linnean Society of London (New York, 

 Holt). In about two hundred and fifty duo- 

 decimo pages the author discusses the evolu- 

 tion of plants most entertainingly and lu- 

 cidly, confining himself, however, to the flow- 

 ering plants and the " higher spore plants." 



