8o American Quarterly Microscopical Journal. 



On the Isogenic Groups of the Cellular Elements of Car- 

 tilage. — J. Renaut. — Comptes Rendus, July, 1878. 



On the Gum Disease of Citrons. — Continued. 



This article is somewhat long, although the experiments are incom- 

 plete, and are only published because the author, having left Sicily, does 

 not expect to find opportunity to conduct them further. 



The disease appears to be caused by, or, at least, accompanied by, a 

 new cryptogam excessively minute and very prolific, which is named 

 Fussisporium limoii, Briosi. The description given of this fungus is 

 entirely too long to quote in this place. Unfortunately its charactejs 

 are not given in technical language. 



A New Field of Study for the Microscopist. — Continued. 



Dunkirk Microscopical Society. — Report of meeting of July 16, 

 from Dr. C. P. Ailing, Secretary. 



Dr. Edmund's Paraboloid. — A short description. 



Microscopical Technic. — Extract from Dr. Pelletan's Manuel of 

 Histology. 



THE AMERICAN JOURNAL OF MICROSCOPY. 



August, 1878. Extra number. 



On the Life-History of a Minute Septic Organism, with an 

 Account of Experiments made to Determine its Thermal 

 Death Point. — Rev. W. H. Dallinger. — From the Proceedings of the 

 Royal Society, No. 187, 1878. To Mr. Dallinger we are indebted for a 

 great deal of patient and careful work, and our knowledge of the life- 

 history of the minute monads we owe almost entirely to him and his co- 

 worker. Dr. Dr>^sdale. 



No one who has studied the results of this labor can overlook the 

 evident similarity in the methods of development and multiplication 

 shown by all these organisms and still less can we fail to admire the 

 true spirit of investigation shown by the gentlemen who have done this 

 work, the skill they have shown in conducting it, and the fertility of 

 invention which has enabled them to overcome the difficulties involved, 



In this last paper Dr. Dallinger describes the organisms with his ac- 

 customed care, and then watches them until the process of self division 

 is fully made out. This process is the same for the most part as he 

 has noticed in other forms, the body and nucleus divide longitudinally, 

 the division continuing until the two new forms are separated by the 

 finest shred of sarcode, which soon breaks about the middle, and thus 

 becomes a flagellum for each of them. 



As was anticipated from previous experiments on other forms, he 

 finally succeeded in obtaining cysts, as the result of conjugation, from 

 which spores were finally discharged, and these latter develop into the 

 original form. 



This paper is illustrated with two well-executed plates, and takes up 

 the greater part of the journal. 



