ner-Sandoval (Dissert. Strassburg, 1898) has convinced us that the true oospora varieties are much larger although similarly constructed organisms, we also, with this author, consider the name actinomyces (Harz) at present the most correct.

Some varieties of wide practical importance, closely related to bacteria, but reminding one very strongly of true algi (oscillaria), have been included under Supplement II.

If we cast a glance over this system, we can not deny that the families and genera are often connected by transition varieties; we recall only the following: The border between the coccaceæ and bacteriaceæ is obliterated by oval and lance-formed (!) cocci and certain extremely short bacilli (compare, in the special part, Micr. melitensis, Bacterium Fraenkelii); between streptococcus and micrococcus, micrococcus and sarcina, it is often unsafe to distinguish. In the cycle of growth of many bacilli twisted forms occur; flagella and endospores occur in such various forms that it would lead to an entirely unnatural grouping if the attempt were made to found a classification that depended in part upon the flagella or endospores.

The Bacterium Fraenkelii Hashimoto, for which we are indebted to the kindness of the authors, unfortunately died before we could study it.

Upon solid nutrient media the organism forms short rods with polar flagella; upon fluid media, on the contrary, it forms quite long chains of cocci and occasionally sarcina forms. Thus it connects the coccaceae with the bacteriacea, as does the Micr. melitensis, and shows, as we have indicated above in other examples, that sarcina forms occur as growth forms in cocci and that the presence of flagella is also variable. (See Hashimoto, Z. H. xxx1, 85.)

B. Systematic Description of the Most Important Varieties of Fission-fungi.

INTRODUCTORY REMARKS TO THE SYSTEMATIC PART, ABBREVIATIONS, ETC.

1. We have described about eighty species as completely and exhaustively as possible, several hundred are briefly described, and many

varieties which we are not acquainted with in detail are briefly referred to in the connection where they belong.

2. The colonies, slightly magnified, are described and drawn with closed diaphragm, and so placed that the peripheral portions are sharply visible.

3. For the drawings and descriptions plates with a medium number of colonies, 60 to 100, were always employed. Usually the smaller colonies were selected.

4. All statements, unless otherwise qualified, regarding the growth upon gelatin apply at a temperature of 22°, upon agar at 37°.

5. When nothing particular is said regarding the color and consistency in the description of the agar streak culture, and of the surface growth in the agar stab culture, they are the same as upon the agar plate.

6. Regarding the formation of pigment, odoriferous, gustative, and other metabolic products nothing has been said unless special investigations have been made upon the same.

7. Our original purpose of treating exhaustively the resistance of all important varieties to injurious influences has been abandoned as being too far-reaching. This decision was also partially dependent upon the fact that the statements of authors often deviate so widely. Therefore we have restricted ourselves to making complete statements regarding some varieties (Micr. pyogenes, Strept. pyogenes, Strept. lanceolatus, Bac. anthracis, Bact. typhi, Corynebact. diphtheria, Mycobact. tuberculosis, Vibrio cholera).

8. References to the illustrations in the atlas are always given thus: Plates with Arabic numerals, figures with Roman. Thus, 5, VIII, signifies figure VIII in Plate 5.

The introductory remarks of the separate sections, coccaceæ, bacteriaceæ, spirillaceæ, are also to be heeded.

Statement of the Terms Employed by Us in the Description of Cultures of Bacteria.

I. STAB CULTURES.

A.

Not liquefying.

1. Stab canal:

(a) Thread-like: Uniform growth without anything especially characteristic.

(a) Smooth.

(3) Rough.

(b) Nodular: The stab canal is beset with larger or smaller tubercles, points or teeth.

(c) Hairy: The stab canal is beset with delicate longer or shorter undivided spurs, which are (a) parallel, (3) curled, ()) matted.

(d) Branched: The stab canal is beset with dividing outgrowths. (e) Beaded: The stab canal consists of small roundish or round connected colonies.

(f) Band-like: Growth as a small band, produced by making the stab canal with a loop.

2. Surface growth:

Here the same applies as to the non-liquefying superficial colonies in the plate.

B. Liquefying.

(a) Fixed form of liquefaction, if the zone of liquefaction following the stab becomes larger, but assumes substantially no other form than at the beginning.

1. Tube shaped: Slowly, weak, and small.

2. Stocking shaped: Sack-shaped, rapid, strongly, at times with scalloping of the walls.

3. Vesiculated: Bubbles are formed and confined in the depth. (b) Variable form of liquefaction.

I. Initial stage:

1. Saucer shaped.

2. Funnel shaped.

3. Flattened funnel shaped.

II. Advanced stage:

1. Cylindrical: The liquefaction extends more above and soon reaches the glass, and then extends, with a horizontal limiting surface, downward.

2. Funnel shaped: The liquefaction extends more uniformly from the culture. The funnel shape is preserved still in later stages. Often the second form is succeeded by the first.

II. STREAK CULTURES.

A. Surface growth: The same designations apply as to the surface cultures upon plates.

B. Water of condensation.

(a) Clear, with or without sediment.

(b) Cloudy, with poorly defined sediment.

(c) Pellicle on surface.

III. BOUILLON CULTURES.

A. Fluid:

(a) Clear.

(b) Cloudy.

(c) Syrupy, gelatinous.

B. Sediment:

(a) Cloudy.

(b) Flocculent, if upon shaking it rises as a twisted column, and can be homogeneously distributed.

(e) Sandy, if it lies steadily at the bottom and, upon shaking, is distributed as small fragments.

IV. POTATO CULTURES.

The same designations apply as to the streak and plate cultures.

V. PLATE CULTURES.

A. Without liquefaction.

(a) Form:

1. Point-like, when the dimensions are very slight.

(e) Peculiarity of border, especially slightly magnified with microscope:

(a) With compact original colony.
(3) With original colony disintegrating.

2. Diffusely cloudy.

Special Introductory Remarks Concerning the Coccaceæ. Spherical Bacteria.

1. Since almost all the varieties presented, with the exception of the Micr. gonorrhoea, stain with the ordinary anilin dyes and by Gram's method, we usually state nothing regarding the staining properties, except when they can not be stained by Gram's method.

2. When no mention is made of flagella and spores, they are absent.

3. No mention is made of the intense stain with watery solutions of anilin dyes, which occurs with all varieties, and a similar statement would have to be always repeated. It is strongly recommended, when it is desirable to obtain the cement substance between the bacterial cells unstained (capsules), to employ a dilute aqueous solution of anilin dyes, or after staining with stronger solutions to employ dilute acetic acid as a decolorizing agent, or to use Gram's method. This is obligatory in the case of sarcina and diplococci in order to render the line of fission in dividing cocci visible, etc. (An exception is the gonococcus.)

4. Since all varieties of the genus micrococcus not infrequently occur as diplococci, tetrads, and short chains, we have only said anything regarding the grouping when there is something special to notice.

5. For an exhaustive discussion upon suppuration and the part played by micro-organisms in the same, see Kurt Müller, C. B. xv, 735, and Poliakoff, C. B. xviii, 33.

FAMILY I.-COCCACEAE. SPHERICAL
BACTERIA.

Family diagnosis and genera scheme, see page 122.

1. Streptococcus (Billroth).

The cells divide only in one direction of space at right angles to the direction of growth, so that if the multiplying cells remain attached to each other, shorter or longer rosary-like chains are formed. Often the chain appears to be be built up from distinct pairs. Chains are formed with most constancy in bouillon; upon gelatin and agar,