18971 MICROSCOPICAL JOURNAL. 22'J 



more properly, softened in acetic acid. I think- there is a 

 tine field for experiment, for anyone who has the time in 

 devising- an a<]ueoiisju;-unimy medium, applicable especially 

 to unstained veg-etable mounts. C. M. Vokck. 



Molasses as an ingredient of the Cell was formerly 

 used to prevent cracking- ; but it proved a mistake which 

 caused the loss of many tine slides, as in all cases black 

 spots appeared sooner or later. 



The best cell I know of for balsam mounts is made of Le 

 Pag-e's g-lue and some insoluble water color. They dry 

 in an hour or two after being- made, and will hold forever. 



D. B. Ward. 



Are the very small black particles that form these spots 

 evolved from the chemical constituents of the molasses, or 

 are they from the bone-black filters used in its manufac- 

 ture? LePag-e's g-lue is probably g-lue or g-elatin dissol- 

 ved in a strong- solution of borax, and, if covered exter- 

 nally with a g-ood water-proof finish, it would seem to be 

 permanent. S. G. S. 



BACTERIOLOGY. 



Fossil Bacteria.— M. B. Renault has long- worked at 

 the identification of bacteria found in g-eolog-ical strata, 

 and now publishes the g-eneral results of his observations 

 in a paper illustrated with a larg-e number of drawing-s. 

 As mig-ht be expected from their simple structure, bacteria 

 appear to have been coeval with the tirst appearance of 

 org-anic life on the earth, the coccoid form being- apparently 

 earlier than the bacillar. Indications of their presence are 

 found in bone, teeth, scales, and coprolites, as well as 

 abundantly in veg-etable tissues. Spores and sporang-es of 

 ferns appear to have been esjiecialiy subject to their 

 attacks. The species are, as a. rule, distinct from those 

 at present in existence. — Ann. des Sciences Naturelles. 



Bacterial Diseases of Plants. Dr. V. Peg-lion descri- 

 bes in Malpig-hia a disease which attacks the stem of the 

 hemp, causing- disinteg-ration of the tissues. It ai)])ears to 



