244 The Botanical Gazette. [April 
similar titles are at variance with the accepted principles of the bino- 
mial nomenclature. 
Migula’s classification is based primarily on morphological and de- 
velopmental differentiation, and in the selection of these characters 
he uses those that are the most permanent, subordinating the more 
transient, such as the presence and distribution of cilia, to lesser di- 
visions. 
The following synopsis gives the salient features of his system: 
I. Cells when isolated spherical, not elongating before cell division 
Cell division in 1,2 or3 planes... . . . . . . 1. Coccatte 
II. Cells cylindrical (short or long) dividing in only one plane, and 
elongating before division. 
a. Cells straight, rod-like, devoid of sheath, immotile or motile 
by means of cilia, . . pee . 2, Bacteriaite, 
b. Cells curved, without sheath, . . . . . . . 3. Spirillacte 
c. Cells surrounded with a sheath, . 4. Chlamydobacteriaa. 
d. Cells without sheath, united into filaments, motile by undulating 
membranes, . . . 5. Beggiatoacte. 
The division of genera in the different families is likewise accom 
plished by the use of morphological characters such as the presence 
or absence of locomotor organs, protoplasmic inclusions like sulfur 
grains and, in the more specialized groups, the arrangement of cell fila 
ments. Biological characters such pathogenicity, chromogenes!s and 
zymogenesis are only used to differentiate related groups in various 
genera. 
No attempt is made to classify all of the species already recorded, 
but a brief description is appended of a few representative forms 
under each group. The system will doubtless be regarded as th 
most successful attempt that has yet been made to outline the class 
fication of this group on morphological lines. Fl 
It certainly represents an advance over any of its predecessors, ° i 
18 Superior to the contemporaneous systems that have been suggest m 
within the last few years. The prestige of the publication of ee 
forms a part will doubtless strengthen its authority and lead (0! 
adoption by botanical bacteriologists.—H. L. RussELt. 
Minor Notices. 
_The authors have recently issued decades xvi1 and xvii of © 
tice Americana, prepared by L. M. Underwood and O. F. Cook 
has been three years since the last decades were issued, and ie io 
pleased to find that there has been no abatement of the origin#! ie 
to issue exsiccate of all the North American species. There ws 
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