14 



SCIENCE. 



[N. S. Vol. XX. Xo. 496. 



schools and colleges, since few medical 

 schools will have the equipment or be able 

 to afford the time to do it properly. Physi- 

 ological chemistry will become then a first- 

 year study in all of our medical courses, 

 and the young man beginning the study of 

 medicine rpust bring with him a knowledge 

 of general inorganic and organic chemistry 

 sufficiently broad to enable him to grasp 

 the new problems which medicine now pre- 

 sents. 



J. H. Long. 



NOETHWESTEKN UNIVERSITY, CHICAGO. 



SCIENTIFIC BOOKS. 

 Eandbuch der Pisclikrankheiten. Von Dr. 

 Bruno Hofer, Professor der Zoologie an 

 der tierarztlichen Hochschule und Vorstand 

 der Kgl. Bayer. Biol. Versuchsstation fiir 

 Pisclierei in Miinchen. Mit 18 Parben- 

 tafeln und 222 Text-Abbildungen. Verlag 

 der Allg. Fiscberei-Zeitung, Miinchen. 1904. 

 This is the first book devoted exclusively 

 to the diseases of fishes, a volume of 359 

 pages well printed and Vifell illustrated. The 

 author asserts that the first aim of his work 

 has been to aid the practical fish culturist 

 and secondarily to gather together the sub- 

 stance of the few widely scattered scientific 

 papers on _ the subject and his own unpub- 

 lished material, the result of his observations 

 as director of an experiment station. No 

 technical knowledge is necessary to make use 

 of the book. Particular diseases are described 

 under the heads of external symptoms, course, 

 cause, cure and prevention, the pathological 

 changes receiving but passing notice. The 

 scope of the work is limited to middle Europe 

 and to fresh-water fishes alone, with Siebold's 

 ' Die Siisswasserfische von Mitteleuropa ' as a 

 basis of nomenclature. 



The book is divided into four sections. 

 These treat of general infections, diseases of 

 special organs, the crayfish disease, and gen- 

 eral measures against fish diseases. Pourteen 

 bacterial diseases are described, of which six 

 are regarded as specific infections, and the 

 characters of the organism are summarized. 

 The disease itself is given a distinctive name. 



as ' furunculosis,' ' purpura cyprinorum,' 

 ' pestis salmonis,' etc. The last is the 

 widely known so-called fungous disease of 

 salmon which engaged the interest of Huxley, 

 who believed it to be caused by Saprolegnia 

 alone. Dr. Hofer accepts the work of Pat- 

 terson, who holds the fungus to be a secondary 

 or terminal attack and describes ' Bacillus 

 salmonis pestis ' as the primary cause. It is 

 further interesting to note that the bacillus of 

 tuberculosis is found in fishes, a form recog- 

 nizably different from the parasite in man 

 and not pathogenic for warm-blooded animals. 

 Seven other organisms are found associated 

 with disease, but their role is not regarded by 

 the author as satisfactorily- determined. In- 

 fections of fishes with bacteria and animal 

 parasites are not unknown in this country, 

 but serious epidemics due to them have been 

 described only among domesticated fishes, 

 while in Europe they seem to be more common 

 and devastate alike the natural habitats as 

 well as the ponds of breeders. 



Two general infections with protozoan para- 

 sites are described, each caused by a myxo- 

 sporidian of the genus Myxoholus. A sys- 

 tematic list is given, profusely illustrated and 

 with a short characterization of each species, 

 of the sporozoa parasitic for fishes, in which 

 Gurley's U. S. Pish Commission paper is 

 largely drawn upon. This plan of illustrated 

 synopses of the species is carried out with 

 each group of parasites, more extensively with 

 the Crustacea. 



The second section occupies two thirds of 

 the book and is taken up with local diseases. 

 The skin affections receive most attention and 

 its lesions are mainly caused by parasites, the 

 most important being the saprolegnious fungi, 

 the great enemy of domesticated fishes. None 

 of the tissues or organs is without its patho- 

 logic affection. Even the nervous system is 

 the seat of parasitism, the author himself 

 having investigated a yet unnamed sporozoan 

 which causes in trout ' taumellirankheit,' a 

 torpor finally ending in death. Other au- 

 thors have described * polyneuritis parasitica ' 

 due to a Myxoholus, and a parasitic worm. A 

 short chapter is given to an unexplained ex- 

 ophthalmia, a symptom frequently seen as a 



