10 The Microscope. 



onion cells, mostly rod forms 2// to 10 long, by about 1/j. more 

 or less wide ; sub-C3'lin(lrical bodies, the longer individuals 

 slightly curved, ends squarish, often very active, especially in 

 the young. 



Micrococcus giganteus (provisional name, perhaps), N. S. — 

 Cocci, very large, oval, oblong, or less frequently spherical, with 

 a bright spore or nucleus variously placed ; light translucent 

 bodies with a very thin cell wall and clearish contents. Measure- 

 ments of those of circular outlines 2, 3, 4, rarely 5/^-, in diameter ; 

 of the ovals 4, 5, 6, 7, 8, 9;/ in longest diameter, rare individuals 

 much longer, b}'' 3, 4, 5,'j. wide, or slightly more or less ; the ver^^ 

 longest specimens often contain two or three nuclei, but no 

 chain-like forms ; sometimes none of these would be seen in a 

 dense field of the cocci. This is decidedly the largest, most 

 bold-looking Micrococcus I have 3^et seen or have read of. It is 

 magnificent. At first I thought I had large fields full of some 

 mould spores. It occurs singly, often so numerous in old rot- 

 ting onion bulbs as to fill the field of the microscope very 

 densely in a single layer. It appears soon after the Bacterium, 

 refringente^ also in the water-mounted slides kept for several 

 days. 



As the Micrococcus crepusculum, Cohn, is found in various 

 putrefying fluids associated with Bacterium termo, Duj., so we 

 fiiid this Micrococcus giganteus associated with our Bacterium 

 refringente in decomposing onions. The much greater size 

 makes this to differ widely from the former pair. I find nothing 

 in Crookshank's Manual of Bacteriology, last edition, 1887, to 

 compare in size with our Bacterium refringente and Micrococcus 

 giganteus in this working brotherhood of bacteria for the reduc- 

 tion of organisms to their primitive elements. 



In offering this preliminary notice of my studies on the 

 growth and decay of plants, as seen in the onion, I feel that 

 much time is needed to get its complete history free from all 

 error — much more time than I now have at command. I hope 

 that many others, both present workers and new recruits, may 

 help to carry the work onward. 



