Journal of Applied Microscopy. 311 



Frogs have long been used to demon- 



Russell,F.H. An Epidemic, Septicemic Disease , , , , . biolocrv 



Among Frogs Due to the Bacillus Hydro- ^trate the laws and taCtS Ot DlOlOgy, 



philus Fuscus. Jour, of the American Medi- and the animal has rarely shown evi- 



cal Association, June i8, 1898. evidences of disease; but in 1891, 



Sanarelli was seriously interrupted in his work by an epidemic which broke out 

 among the frogs in his laboratory. He found that the disease was due to a 

 bacillus to which he gave the name mentioned in the title. Two years later a 

 serious mortality among the frogs in the laboratory induced Trambusti to make 

 an investigation. He found the disease to be due to a bacillus which he identi- 

 fied as the one described by Sanarelli. In the same year the bacillus was also 

 identified by Rogers. In 1897 a severe epidemic, due to the same bacillus, 

 broke out among the frogs at Rush Medical College (Chicago). The present 

 paper, from that college, gives a review of previous work and adds a substantial 

 contribution. The bacillus is a water organism, has one flagellum, is chromo- 

 genic, gas producing and aerobic, but also grows to some degree without oxygen. 

 It grows upon all culture media. It is pathogenic for frogs, toads, salamanders, 

 lizards, sunfish, and eels. It is also fatal to many warm-blooded animals. The 

 organism produces toxins of two sorts, one resembling digitalis and the other 

 veratrin. c. j. c. 



Boyer, Charles S. New species of Diatoms. This paper describes six new species 

 Proc. Acad. Nat. Sci. of Fhila. Oct. 1898. ^^^ ^^^ ^^^ variety of diatoms, one 



species belonging to the genus Rhabdonema and the rest to the genus Biddulphia. 

 In case of one species only one specimen was found, and in another only two 

 specimens. It would be difficult in higher plants to establish species upon so 

 little material, especially in large genera. The descriptions are accompanied by 

 photographs. c. j. c. 



„ ,. ^ ^ . .,.,,.,, It was the purpose of this study to 



Ball, C. R. An Anatomical Study of the Leaves ^ * . 



of Eragrostis. Proc. Iowa Acad. Sci. 4: determme whether the anatomical 



1^97- characters of the leaves of Eragrostis 



are sufficiently well marked and constant to be of value in identifying the species. 



The writer decides that the characters are quite well marked and constant, and 



he accordingly devises an analytical key to the species of the genus. Several 



papers of the same nature have appeared in the same publication. Recent 



work in physiological anatomy by Warming, Grevillius, and other investigators 



shows how readily plant tissues vary as the environment is changed ; especially 



is this variability characteristic of epidermal tissues. Mr. Ball's key to the 



species of Eragrostis is based on such characters as relative size of epidermal 



cells, length of trichomes, and number of parenchyma cells. Anyone who has 



made a study of plants in the field with regard to habitat variations, will recognize 



at once how futile it is to attempt to separate species in the laboratory by means 



of such anatomical characters. If this method is used at all it should be with 



the greatest caution and after the most exhaustive study. The anatomist of the 



future will not try to separate species in this artificial way, but will endeavor to 



bring them together by means of the intergrading forms ; and the basis for this 



work must always be a discriminating study in the field. The attempts to 



