FRESHWATER INVESTIGATIONS DURING THE LAST
FIVE YEARS.

HENRY B. WARD.

It is just five years since the first report was published from
the Plon Biological Station, the first general public enterprise
of that character founded on fresh water and devoted to the solu-
tion of its problems. It is also just five years this summer since
the Michigan Fish Commission inaugurated work on the Great
Lakes by opening a laboratory on Lake St. Clair. The Plon
station has given a great impetus to freshwater work in Ger-
many, and to the efforts of the Michigan Fish Commission and
its corps of scientists can be traced much of the energy now
devoted to lacustrine investigation in this country. The half
decade which has intervened since 1893 has seen great progress
in this field and in view of the general interest taken in fresh
water work at the present time it may not be adjudged untimely
to give a résumé of the results achieved during this brief pe-
riod. It seems fitting also to publish in this connection a bib-
liography which has been the result of much work on my part
and which I hope may be of some service to other workers in
this field, especially as no extended bibliography on this sub-
ject has yet been published and no summary of progress in
this line is available in English at least.

While no effort has been spared to make the list of papers
complete, it is too much to hope that no reference has been
omitted which should have a place in its columns. On the
main lines of investigation, however, I hope that no important
article has been overlooked, but I should esteem it a favor to
have errors or omissions called to my attention by those who
note them. So far as possible all references have been verified
from the original and have been abstracted for the summary of

262 HENRY B. WARD:

progress, but in case of those articles not accessible, which in
the list are designated by a star, it seemed better to make use
of such reviews as were at hand in the various journals, or
given in brief form on the cards of the Bibliographical Council
at Zurich, in order that the cross references might be as com-
plete as possible.

Of course such a bibliography could not reasonably be ex-
pected to give all references on some subjects which are in part
included so that it is perhaps wise to state more specifically the
limits of the work undertaken. With the exception of a single
reference to Hensen, the father of plankton methods, a refer-
ence indispensable to all work, no mention has been made in-
tentionally of any paper except asit deals in part at least with
freshwater investigations. Nevertheless, some of the papers
not seen may easily be devoted to marine studies even though no
reference thereto is contained in the title. The bibliography is
also essentially confined to zoological references although some
of the important papers on physical, chemical and botanical
topics are cited. The papers of this character given are quoted
from many sources, yet certainly do not comprehend all of im-
portance on these topics. Their inclusion here is justified by
their importance and bearing on the general problems of fresh
water work, their immediate relation to the studies of certain
investigators and localities, or their occurrence in such sources
as render them easily accessible to the general student. Under
the topics of taxonomy and geographical distribution, also, no
effort has been made to collate all possible references; the en-
deavor has been rather to include all those papers of general
or special interest and those of most immediate importance and
accessibility to American students. Undoubtedly there is room
here for cousiderable difference of opinion and the special
student of a particular group or region will not find this bibli-
ography extensive enough for his purposes, but I hope none the
ess that itmay be sufficiently representative to give a succinct and
precise idea of the extent of our knowledge as to the distribution
and composition of the freshwater life of the globe and the con-
ditions under which it is found. In the systematic part greater

RECENT FRESHWATER INVESTIGATIONS 2638

emphasis is laid upon those groups which are plankton forms,
whereas others have received at most passing attention. There
is also a considerable amount of literature bearing upon the
technical phases of the subject, in its relation for instance to
the purity of a city water supply, which has been included so
far as references were found without any effort having been
made to cover the entire ground.

It is in dealing with the field of plankton work that I have
endeavored to include every article, however small, and to add
references to such reviews as were noted in order to make
the contents of the originai articles more widely useful.
In this I have been greatly aided by the admirable reviews of
Zschokke in the Zoologisches Centralblatt; more recently Ko-
foid has undertaken similar abstracts in the American Naturalist.
No effort has been made however to distinguish here between
comments, reviews, and abstracts, or to include all such notices
in the bibliography. A slight delay in the printing of the
paper enables me to include references up to the close of 1898.

In so extended a review the method of citation must neces-
sarily be brief yet such as to allow of the ready finding of
papers cited. J have adopted the following:—The name of
the author together with the year of publication of the article,
bearing a letter affixed if necessary, forms the designation of
the paper. The title of the article is not abbreviated, but
written precisely as given by the author. The name of the
journal is shortened as much as consistent with clearness and
three or four which are in constant use, are designated as
follows :

B. C. Biologisches Centralblatt.

J. R. M.S. Journal of the Royal Microscopical Society,
London.

Z. A. Zoologischer Anzeiger.

Z. C. Zoologisches Centralblatt.

The abbreviations vol., pt., p., etc., are entirely omitted

but the following arbitrary order of arrangement will enable
any reference to be read with ease.

264 HENRY B. WARD:

The number of the volume is printed in lower case Roman
numerals, and comes first, except that an antecedent Arabic
figure may designate the series, if such exist. All other num-
bers are Arabic, and the last of these bearing no added desig-
nation is the page number. The latter may however be fol-
lowed by the number of figures or plates in which case these
numbers are always accompanied by a designative abbreviation,
jig. or pl. The number, part, or article, is quoted only when
paged separately, unless there was some uncertainty concerning
some other part of the reference. Many references are
incomplete, because (1) the article was entirely inaccesible,
(2) the reprint in my library did not show the precise location
of the article, or (3) disagreement between my card catalogue
and the printed reference in one of the bibliographical records
left uncertain the source of the error, and the paper referred to
was not accessible here.

An example will perhaps make the method of citation
clearer :

xiv, 4, means vol. xiv, page 4.

xiv, 4, 4, means vol. xiv, part or number 4, page 4.

4, xiv, 4, 4-42, means series 4, vol. xiv, part 4, page 4-42.

xxi, 1-3, 17-92. 4pl. 7 fig., means vol. xxi, part 1to 3,
p- 17 to 92, 4 plates, and 7 text figs.

It is but fitting that I should acknowledge here my in
debtedness to the various sources of information especially the
bibliographical records in zoology; to the many individuals only
a general acknowledgment of the courtesies can be made, but
of my debt to Professor J. E. Reighard of the University of
Michigan, who kindly placed his entire card catalog at my
service, special mention should be made.

oe

RECENT FRESHWATER INVESTIGATIONS 265

BIBLIOGRAPHY.
APSTEIN, C.
93. Ueber das Vorkommen von Cladocera gymnomera in holsteini-=
schen Seen.

Schr. natw. Ver. Schles.-Holstein, x, 1. 4 pp.
Seasonal and numerical data on the species.

94. Vergleich der Planktonproduction in verschiedenen holstein-
ischen Seen.
Ber. Naturf. Ges. Freiburg i’Br., viii (‘‘Festschriit fiir Weis-
mann’’), 70-88. 2 tab.
Rev. Z. C., i, 267-8; B. C., xiv, 319.

96. Das Siisswasserplankton. Methode und Resultate der quanti-
tativen Untersuchung.
Kiel und Leipzig, 200 pp. 118 figs. 5 tab.
Rev. Z. C., iii, 764-9; Natw. Rundschau, xi, 37, 474; Science, n. s.

vi, 140-1.
ATKINSON, E.
*98. Extraordinary Vitality of Entomostraca in Mud from Jerusalem.

Ann. Mag. Nat. Hist., 7, ii, 372-6.
Rev. Nat. Sci., xiv, 64.

Barrois, TH.
*93. Notes préliminaire sur la faune des eaux douces de |’ Orient.
Rev. Biol. Nord France,: iii, 6, 230-4; 7, 277-81; 8, 316-8, 9 Fig.

*94, Contribution a l’étude de quelques lacs de Syrie.
Rey. Biol. Nord France, vii, 6, 224-3138. 3 fig.
Rev. Z. C.,i, 734-6 (=Zschokke, 94a, q. v.); B. C.,xv, 869-73 (=Im-
hof, 95b, q. v.).

96. Recherches sur la faune des eaux douces des Agores.
-Mém. Soe. Se. Agric. Arts, Lille, 5, vi, 172 pp. 3 cartes.
Rev. Z. C., iii, 609-11; B. C., xvi, 683-8 (=Imhof, 96, q. v.).

BEDDARD, F. E.
93. The Fauna of the Victoria regia Tank in the Botanical Gardens.
Nature, xlix, 247.
Tropical animals introduced with aquatic plants.

Beur, A.
*98. Die Fauna der wirbellosen Thiere des Babitsees.
Korr.-Bl. Nat. Ver. Riga, x], 77.
BIGnEY, A. J.

97. Notes on the Biological Survey of Milan Pand.
Proc. Ind. Acad. Sci., 96, 274-5.
Brief preliminary report.

*References not seen by the reviewer are designated by a star.

266
BIRGE,

93.

94.

95.

95a.

97.

97a.

98.

BLANC,

*95.

96.

*98.

HENRY B. WARD:

E. A.
Notes on Cladocera, III.
Trans. Wis. Acad. Sci., ix, 275-317. 4 pl.
Taxonomic, notes on distribution.
A Report on a Collection of Cladocera mostly from Lake St.
Clair, Michigan.
Bull. Mich. Fish Comm., 4, 45-7. 1 table.
Faunal list and discussion of species.
On the vertical distribution of the pelagic crustacea of Lake
Mendota, Wis., during July, 1894.
B. C., xv,. 353-5.
Résumé of the following article.
Plankton Studies on Lake Mendota. I. The Vertical Distribution
of the Pelagic Crustacea during July, 1894.
Trans. Wis. Acad. Sci., x, 421-84. 4 pl.
Rev. Z. C., ii, 347-8.
The Vertical Distribution of the Limnetic Crustacea of lake
Mendota.
B. C., xvii, 371-4. Rev. Z. C., iv, 606-7.
Preliminary report on the work published in the next paper.
Plankton Studies on Lake Mendota. II. The Crustacea of the
Plankton, July, 1894-Dec., 1896.
Trans. Wis. Acad. Sci., xi, 274-448. 28 pl.
Rev. Z. C., v, 345-51; Am. Nat., xxxii, 282-4.
The Relation between the Areas of Inland Lakes and the Tem-
perature of the Water.
Proc. Am, Fish. Soe., xxvii, 99-105. 1 chart.

lel
Les Résultats d’une série de péches pélagique f faites in 1894-5,
dans le Léman.
Arch. sci. phys. et nat, Genéve, 3, xxxiv, 460-2.
Rey. Z. C., iii, 314.
Sur le Plancton du lac Léman, sa distribution horizontale et
verticale et sur les espéces les plus abondantes.
Actes Soc. helvet. sc. nat., lxxvii, 46-9.
Plancton nocturne du lac Léman.
Bull. Soc. Vaud. se. nat., 4, xxxiv, 128, 225-30; 129, 34-5.
Abst. J. R. M. S., 98, 618.

BLANCHARD, R., ET RICHARD J.

97.

Sur la faune des lacs élevés des Hautes-Alpes.
Mém. Soe. Zool. France, x, 43-61. 1fig. 1 tabl.
Rey. Z. C., iv, 512; B. C., xviii, 169-73 (= Imhof, 98, q. v.).

BLOCHMANN, F.

95.

Die mikroscopische Thierwelt des Siisswassers I. Protozoa.
Hamburg, 2 aufi., 4°, 134 pp. 8 taf.
Rev. Z. C., iv, 285-6.
Chiefly taxonomic.

RECENT FRESHWATER INVESTIGATIONS 267

Boumie, L.
98. Beitrage zur Anatomie und Histologie der Nemertinen.
Zeit. f. wiss. Zool., lxiv, 479-564. 5 pl.; also Arb. Zool. Inst. Graz,
vi, 1; Rev. Z. C., v, 666—72. :
Morphological. Valuable discussion of freshwater species.
BORELLI, A.
95. Viaggio del dott. A. Borelli nella Repubblica Argentina e nel
Paraguay. XIII. Planarie d’acqua dolce.
Boll. Mus. Zool. Torino, x, 202, 1-6. Rev. Z. C., iv, 347.
Faunistic. Rarity of species noteworthy.

Brapy, G. S., AND NormMAN, A. M.
*96. A Monograph of the Marine and Freshwater Ostracoda of the
North Atlantic and Northwestern Europe. Part II.
Sci. Trans. Roy. Soc. Dublin, v, 621-746. 19 pl.
Abst. J. R. M. S., 96, 310-1.
BREWER, A. D. :
98. Astudy of the Copepoda found in the vicinity of Lincoln, Neb.
Jour. Cin. Soc. Nat. Hist., xix, 119-38, 1 pl.; also in Stud. Zool.
Lab. Univ. Nebr. No. 29.

BROCKMEIER, H.
98. Siisswasserschnecken als Planktonfischer.
Forsch-ber. Biol. Stn. Plon, vi, 165.

BRUNER, L.
95. Animal Life in Thermal Springs. Insect Life, vii, 413-4. 1 fig.
BRUYANT, CH.
*94. + Bibliographie raisonée de lafaune et dela flore limnologiques de
lV Auvergne.
Revue d’Auvergne, Clermont-Fd. 8°. 92 pp.
BUTSCHINSEY, P.
96. Die Protozoen-Fauna der Salzsee-Limane bei Odessa.
Z. A., xx, 194-7. Abstr. J. R. M. S., 97, 300.
CaLKIns, G. N.
93. A Study of Odors observed in Drinking Waters of Mass.
Ann. Bept. Mass. Bd. Health, xxiv, 355-80. 1 pl.
93a. Seasonal Distribution of Microscopic Organisms in Surface
Waters.
Ann. Rept. Mass. Bd. Health, xxiv, 388-92.
Cal, R. E.
97. The Hydrographic Basins of Indiana and Their Molluscan Fauna.
Proc. Ind. Acad. Sci., 96,.247-58. 1 pl.
CHILTON, C.
*94. Thesubterranean Crustacea of New Zealand; with some gen-
eral remarks on the fauna of Caves and Wells.
Trans. Linn. Soe. London, Zool. 2, vi, 163-284, 8 pl.
Rey. Z. C., iii, 789-801, 821-7.

268

HENRY B. WARD:

Cuopat, R.
97. Etudes de biologie lacustre.
Bul] Herb. Boissier, 4, v, 289-314. Pl. Rev. Z. C., vi, 84.
Cuoy, C.
*96. Zur Biologie der pelagischen Siisswasserfauna.

Jahresb. Schles. Ges. vat. Cult., Zool-bot. sect., xxxvyii, 80-3.

COCKERELL, T. D. A.

96.

Proposed Biological Station.
Psyche, vii, 242, Suppl. 1, 32.

DaDAY, EUG. VON.

*94.

97d.

98.

Beitrage zur Kenntniss der Microfauna der Natronwasser des
Alféldes. (Czeckish; latin diag.)
Naturhist. Hefte.
Beitrage zur Kenntniss der Microfauna der Tatraseen.
Term. Fiizetek, xx, 149-96.
Rey. Z. C., iv, 607.
Die Fauna des Balatons. IV. Nematoden.
Result. wiss. Erforsch. Balatonsees, ii, 1, 81-119.
Faunistic-systematic. Large number of species.

Die Fauna des Balatons. V. Rotatoria.
Result. wiss. Erforsch. Balatonsees, ii, 1, 121-33.

Die Fauna des Balatons. IX. Crustaceen.
Result. wiss. Erforsch. Balatonsees, ii, 1, 163-93. 40 fig.
Rey. Z. C., v, 374-5.

Die Fauna des Balatons. X. Wassermilben (Hydrachniden).
Result. wiss Erforsch. Balatonsees, li, 1, 195-205.
Faunistic-systematic. Scanty representation.

Mikroskopische Siisswasserthiere aus Ceylon.

Term. Fiizet., xxi [Anhanghsheft], 123 pp., 55 text fig.
Rev. Z. C., v, 601-3; Am. Nat., xxxii, 880.

DAHL, FR.

94.

Die Copepodenfauna des unteren Amazonas.
Ber. naturf. Ges. Freiburg i’Br., viii, 10-22. 1 pl.

DE GUERNE, J. G., see Guerne, J. G. de.
DOLAN, J. P.

97.

Temperature of Lake Wawasee.
Proc. Ind. Acad. Sci., 96, 279-86.

DOLuey, C. S.

96.

The Planktonokrit, A Centrifugal Apparatus for the Vol-
umetric Estimation of the Food-supply of Oysters and other
Aquatic Animals.

Proc. Acad. Nat. Sci. Phila., 96, 276-89. 1 fig.

DroscHER, W.

*97.

Zur Begriindung einer rationellen Fischwirthschaft.
Allg. Fisch. Zeit., xxii, 9-10.

RECENT FRESHWATER INVESTIGATIONS 269

*97a, Beitrag zur Kenntniss der Nahrung unserer Fische.
Allg. Fisch. Zeit., xxii, 19, 361-6; 20, 383-8.

*97b. Ein Beitrag zur Biologie der Seen.
Allg. Fisch. Zeit., xxii, 19, 369-71.

Drown, TuHos. M.
93. Onthe Amount of Dissolved Oxygen in the Waters of Ponds

and Reservoirs at Different Depths, in Winter under the Ice.
Ann. Rept. Mass. Bd. Health, xxiv, 383-42.

DuPL.Essis, G., see Plessis, G. du.
DysBowskI, B.
*98. Switez. [Der Switez-See. ]
Kosmos, Lemberg, xxii, 5, 252-75.
ECKSTEIN, K.
*95. Die Rotatorienfauna des Miiggelsees. [Aus. d. Biol. Station d.
deutsch. Fischerei-Vereines. ]
Zeit. f. Fischerei, iii. 5pp. 7 figs.
Rev. Z. C., ii, 756-7.
Scantily represented.
EIGENMANN, C. H.
95. Turkey Lake as a Unit of Environment and the Variation of its
Inhabitants. (With faunal lists by numerous collaborators).
Proc. Ind. Acad. Sci., v, 204-96.
EnTz, G.
96. Protozoa. Fauna regni hungariae.
Reg. Soc. Sci. Nat. Hung. Budapest. 29 pp.
Fauna! list.

97. Einleitung und allegemeine Betrachtungen tiber die Fauna
des Balatonsees.
Result. wiss. Erforsch. Balatonsees, ii, 1, 5-39. 5 fig.
Rev. Z. C., v, 351-2: Am. Nat., xxxii, 791-3.

EVERMANN, B. W.

93. The Investigation of Rivers and Lakes with Reference to the
Fish Environment.
Bull. U. S. Fish Comm., xiii, 79-73.
Scope of work under the commission—outline for lake work.

FIELD, G. W.
96. Scientific Agriculture.
Rept. R. I. Bd. Agl., 96, 94-8.
97. Onthe Plankton of Brackish Water. [Abstract.]
Science, n. s., v, 424-5.
98. Use of the Centrifuge for collecting Plankton. [Abstract. ]
Science, n. s., vii, 201.
98a. Methods in Planktology.
Rept. R. I. Exp. Sta., x, 2, 120-49; Am. Nat., xxxii, 735-45.
FitzGERALD, D.
95. The Temperature of Lakes.
Trans. Am. Soc. C. E., xxxiv, 67-114.

270 HENRY B. WARD:

ForBeEs, E. B.

97. A Contribution to a Knowledge of North American Freshwater

Cyclopidae.

Bull. Ill. Lab. Nat. Hist., v, 27-82. 18 pl.

Rev. Z. C., iv, 839-40.

Systematic monograph with important biological data.
FORBES, S. A.

93 A Preliminary Report on the Aquatic Invertebrate Fauna of the
Yellowstone National Park, Wyoming, and of the Flathead Region
of Montana.

Bull. U. S. Fish Comm., xi, 207-58, 6 Pl.
Rev. Z. C., i, 396-8; B. C., xiv, 287-93 (=Imhof, 94, q. v.)

94. Illinois State Laboratory of Natural History, Champaign, Il.
Biennial Report of the Director 1893-1894.

Chicago: Hornstein Brothers. 8°, 86 pp., 15 pls..
Cf. Nat. Sci., viii, 228-9; Science, n. s., ii, 729-30.

97. Biennial Report of the Biological Experiment Station, 1895-6.
Chicago. 35 pp. 20 pl. Cf. Nat. Sci., x, 365.

FORDYCE, CHAS.

98. Anew Plankton Pump.

Proc. and Coll. Neb. St. Hist. Soc., 2, ii, 293-6; also Studies Zool.
Lab. Univ. Nebr., No. 25. 2 fig.
Rev. Z. C., v, 698.

FOREL, F.-A. .
92. Le Léman. Monographie Limnologique. Lausanne, i, 539 pp.
94. Zoologie lacustre.

Arch. sci. phys. et nat. Genéve, 3, xxxii, 588-605.
Rev. J. R. M.S., 95, 161.

95. Le Léman. Monographie Limnologique. Lausanne, ii, 651 pp.

*96. Sur le Plancton du lac Léman.
Boll. Soc. Vaud. se. nat., 4, xxxii, 121, 32-3.

FrANcp, R. H.
94. Zur Biologie des Planktons. Vorlaufige Mittheilung.
B. C., xiv, 88-8. Cf. corrections by Hensen; B. C., xiv, 201.
Rey. Z. C., i, 308.
07. Die Fauna des Balatons. I. Protozoen.
Result. wiss. Erforsch. Balatonsees, ii, 1, 1-64.
Rev. Z. C., v, 322-3.
*97a. Der Organismus der Craspedomonaden.
Budapest, 1897. Rev. Z. C., v, 558-60; B. C., xviii, 535-6.
A monographic discussion of the group, including important
biological notes.
FRENZEL, J.
*95. Die Biologische und Fischerei-Versuchsstation ‘“Muggelsee’’.
Bericht tiber die Jahre 1893 und 1894.
Zeit. f. Fisch., iii, 58-114. 4 fig. Also apart Berlin.

RECENT FRESHWATER INVESTIGATIONS "O71

*95a. Die Bedeutung der biologischen Station fiir die fischwirth-
schaftliche Praxis.
Zeit. f. Fisch., iii, 175-8.
97. Zur Planktonmethodik. I. Die Planktonpumpe.
B. C., xvii, 190-8.
Abst. J. R. M. S., 97, 199.
97a. Zur Planktonmethodik. II. Die Seidengaze.
B. C., xvii, 364-71.
97b. Untersuchungen uber die mikroskopische Fauna Argentiniens
I. Die Protozoen. 1, 2. Die Rhizopoden und Helioamoeben.
Bibl. Zool., 12, 166 pp. 10 Taf.
Rev. Z. C., v, 392-3.

Fri, ANTON.

97. Fresh-water Biological Stations. Europe’s Example.

Nat. Sci., x, 169-72. 2 fig.
Fric, ANT. UND VAVRA, V.

94. Untersuchungen tiber die Fauna der Gewasser Bohmens. IV.
Die Thierwelt des Unterpocernitzer und Gatterschlager Teiches.
Arch. Natw. Landesdurchforsch. Béhmen, ix, 2, 124 pp. 80 fig.
Rey. Z. C., i, 786 (=Zschokke, 94a, q. v.); Nat. Sci., v, 870-5.

97. Untersuchungen iiber die Fauna der Gewasser Béhmens III.
Untersuchung zweier Bohmerwaldseen, des Schwarzen und des
Teufelsees.

Arch. Natw. Landesdurchforsch. Bohmen, x, 3, 74 pp. 32 fig.
Rev. Z. C., v, 158-9; Am. Nat., xxxii, 789-91.
FUHRMANN, O.
*94. Die Turbellarien der Umgebung von Basel.
Rey. Suisse Zool., ii, 216-90, 2 Taf.
Rev. Z. C., ii, 390-1.
95. Recherches sur la faune des lacs alpines du Tessin.
Rey. Suisse Zool., iv, 489-548.
Abst. Z. C., iv, 607-8; J. R. M. S., 97, 200.

GARBINI, A.
93. Primi materiali per una monografia limnologica del lago di
Garda.

Mem. Accad. Agric. Art. Verona, 3, lxix, 73 pp.
*Q4, Primi materiali, etc., (93 with additions),

Bull. Soc. Ent. Ital., xxvi, i, 3-50.
Rev. Z. C., i, 552-3.

94a. Appunti per una limnobiotica italiana. I. Protozoa, Porifera e
Coelenterata del Veronese.
Z. A., Xvii, 295-8.
Rey. Z. C., i, 788 (=Zschokke, 94a, q. v.)
Faunal list with biological data.

95. Fauna limnetica e profonda del Benaco. (Osservazioni fatte
nel 1894.)
Boll. Mus. Zool. Anat. Comp. Torino, x, 198, 7 pp.

95b.

95e.

95f.

*96.

98a.

rd
GREVE,
*97.

GUPPY,
.*93,

HENRY B. WARD:

Appunti per una limnobiotica Italiana, II. Platodes, Vermes e
Bryozoa del Veronese.
Z. A., xviii, 105-8.
Rey. Z. C., ii, 139.
Continuation of 94a.
Diffusione passiva nella limnofauna.
Mem. Accad, Verona, 3, 1xxi, 1, 10 pp.
Rey. Z. C., ii, 195-6.
Appunti di carcinologia Veronese.
Mem. Accad. Verona, 3, 1xxi, 1-94 pp., 1 tab.
Appunti per una limnobiotica Italiana. III. Arthropoda del
Veronese-Insecta e Arachnoidea.
Bull. Soc. Ent. Ital., xxvii, 12 pp.
Rev. Z. C., ii, 346.
Continuation of the list in 94a and 95a,
Distribuzione e intensita della fauna atesina (Adige suoi influ-
enti).
Mem. Accad. Verona, 3, ]xxi, 2, 35 pp.
Appunti per una limnobiotica Italiana.IV. Mollusca del Veronese.
Z. A., Xvili, 411-4.
Rev. Z. C., ii, 680-1.
Continuation of the list in 94a, 95a and 95d.
Osservazione biologiche intorno alle acque freatiche Veronesi.
Verona 37 pp. ¢* .
Rey. Z. C., iii, 189.
Intorno ai Nemertini del lago di Garda ed alla loro origine.
Z. A., xix, 125-7.
Aleune notizie fisiche sulle acque de) Benaco.
Rivista Geogr. Ital., iv, 1, 29 pp.
Un pugillo di plancton del lago di Como.
Atti R. Inst. Veneto, 7, ix, 668-79.
Rey. Z. C., v, 487.
Cursory examination. Usual fauna.
Due nuovi Rizopodi limnetici (Diflugia cyclotelliana—Heier-
ophrys Pavesit).
Z. A., xxi, 667-70. 2 fig.
Systematic-faunistic.
C.
Zur Frage iiber die Nahrung der Stisswassertische.
Allg. Fisch. Zeit., xxii, 288-90.
1. BS.
The Distribution of Aquatic Plants and Animals.
Scott. Geogr. Mag., ix, 28-33.

GUERNE, J. G. DE.

93.

A propos d’une Méduse observée par le Dr. Tautain dans le ~
Niger, 4 Bamakou. ;
Bull. Soc. Zool. France, xviii, 225-30.
Rev. Z. C., ii, 19.

‘ae

RECENT FRESHWATER INVESTIGATIONS DMS

GIESBRECHT, W. UND SCHMEIL, O.
¥98. Copepoda. 1. Gymnoplea.
Das Tierreich, 6, 169 pp. 31 fig.
GUERNE, J., ET RICHARD, J.
93. Sur la faune pélagique des lacs du Jura frangais.
C. R. Ae. Sci., Paris, exvii, 187-9. Extr. Rev. Sci., lii, 153.
Rev. Z. C., i, 7-8.
93a. Sur la faune pélagique de quelques lacs des Hautes-Pyrénées
Assoc. frane. avance. Sci., Congress de Pau, 1892.
96. Premiére liste des Copépodes et Cladocéres d’eau douce du
Portugal.
Bull. Soc. Zool. France, xxi, 157-9.
Rev. Z. C., iv, 486. J. R.M.S., 97, 36.
Faunal list—no new forms—mostly common European species.

GUNTHER, R. T.
94. A Further Contribution to the Anatomy of Limnocnida tan-
ganyicae.
Quar. Jour. Mie. Sci., xxxvi, 271-98. 2 pl.
Rev. Z. C., ii, 18-9.
HAnItTscH, R.
*95. The Freshwater Sponges of Ireland with Remarks on the Gen-
eral Distribution of the Group.
Irish Natl., iv, 5, 122-31. 1 pl.
Rey. Z. C., ii, 587-8
Hart, C. A.
95. On the Entomology of the Illinois River and Adjacent Waters.
Bull. Ill. Lab. Nat. Hist., iv, 149-278. 15 pl.
Rey. Nat. Sci., viii, 228-9.
Hartwie, W.

97. Zur Verbreitung der niederen Crustaceen in der Provinz Bran-
denburg.
Forsch-ber. Biol. Stn. Plon, v, 115-49.

*98. Ueber das Vorkommen einiger ‘‘seltener’’ Entomostraken in

der Provinz Brandenburg.
Natw. Wochenschr., xiii, 48-9.
Rev. Z. C., v, 375.

98a. Zur Verbreitung der niederen Crustaceen in der Provinz Bran-
denburg. Zweiter Beitrag.
Forsch-ber. Biol. Stn. Plon, vi, 140-52.
Rey. Z. C., v, 375-6.

*98b. Die Crustaceenfauna des Miiggelsees wihrend des Winters.
Zeit. f. Fisch., v, 113-9.
Rey. Z. C., v, 508.
HEMPEL, A.

96. Descriptions of New Species of Rotifera and Protozoa from the
Illinois River and Adjacent Waters.
Bull. Ill. Lab. Nat. Hist., iv, 310-17. 5pl. Rev. Z. C., iv, 55.
18

2T4 HENRY B. WARD:

97. A List of the Protozoa and Rotifera found in the Illinois River
and adjacent Lakes at Havana, III.
Bull. Ill. Lab. Nat. Hist., v, 301-88. 5 fig.

HENSEN, V.
95. Methodik der Untersuchungen.
Erg. d. Plankton Exp. d. Humboldt Stiftung., i, 200 pp. 11 pl.

Dif. Bemerkungen zur Planktonmechanik.
B. C., xvii, 510-2. -
HERRICK, C. L.
95. Microcrustacea from New Mexico.

Z. A., xviii, 40-7. 29 figs. Abst. J. R.M.S8., 95, 175.

HERRICK, C. L., AND TURNER, C. H.

95. Synopsis of the Entomostraca of Minnesota with descriptions
of related species comprising all the known forms from the United
States included in the orders Copepoda, Cladocera, Ostracoda.
Zool. Ser. ii, State Geol. Nat. Hist. Survey Minn. 525 pp. 81 pl.

HEUSCHER, J.
*93. Vorlaufige Bericht iiber die Resultate’ einer Untersuchung
des Walensees.
Schweiz. Fisch. Zeit., i.
*94, Bericht tiber eine Untersuchung von Teichen im Gebiet des
Kantons St. Gallen.
Schweiz. Fisch. Zeit., ii.
*95. Ueber die Berner-Oberlandseen.
Schweiz. Fisch. Zeit., iii.
Hickson, S. J.
*96. On the Distribution of the Freshwater Fauna.
Trans. and Ann. Rept. Manchester Mic. Soc., 96, 88-99.
Exe. Nat. Sci., xi, 79.
HoeERNES, Rup.

97. Die Fauna des Baikalsees und ihre Reliktennatur.

B. C., xvii, 657-64. Rev. Z. C., iv, 825; J. R. M.S:.97, 024
HoFER, B.

95. [Communication by Comte Eberhard de Zeppelin Ebersberg, q.
v., on the Plankton of Lake Constance. |
Arch. sci. phys. et nat. Genéve, 3, xxxiv, 458-60.

*96. Die Bedeutung von Planktonstudien fiir die Fischerei in Seen.
Allg. Fisch. Zeit., xxi, 355-9.
Hoop, J.
*95. On the Rotifera of the County Mayo.
Proc. R. Irish Acad., 3, iii, 664-706. Rev. Z. C., iv, 179-80.
Hoprpe-SEYLeER, F.

96. Ueber die Verteilung absorbirter Gase im Wasser des Boden-
sees und ihre Beziehungen zu den in ihm lebenden Tieren and
Pflanzen.
Ver. f. Gesch. d. Bodensees u. seiner Umgebung, Heft 24, 20 pp.

RECENT FRESHWATER INVESTIGATIONS O75

Houitrevtpt-Kaas, H.
98. Plankton in norwegischen Binnenseen.
B. C., xviii, 625-36; Rev. Z. C., v, 786-7.
IHERING, H. VON.
95. Os crustaceos phyllopodos do Brazil.
Revista Mus. Paulista, i, 165-80.
Imuor, O. E.
*93. Les organismes inférieurs des lacs de la région du Rhone.
Arch. sci. phys. et. nat. Genéve, 3, xxx, 646-52.
Rey. Z. C., i, 268.
94. Fauna hochgelegener Seen. Seen der Rocky-Mountains, Nord
Amerika. Von S. A. Forbes.
B. C., xiv, 287-93.
Extended review of Forbes, 93.
94a. Die Rotatorien der grossen Seen in Michigan, Nord Amerika.
B. C., xiv, 494-5
Review of Jennings, 94.

95. Tierwelt der hochalpinen Seen.
B, C., xv, 506-17.
Review of Zschokke, 95.

95a. Summarische Beitrage zur Kenntnis der Aquatilia invertebrata
der Schweiz.
B. C., xv, 718-19; Rev. Z. C., ii, 557; J. R. M.S., 95, 618.
95b. Th. Barrois, Fauna der Gewasser Syriens.
B. C., xv, 869-73.
Review of Barrois, Th., 94, q. v.

96. Die Binnengewasser-Fauna der Azoren. Referat nach de Guerne
und Barrois.
B. C., xvi, 683-8.
Review of Barrois, Th., 96, and earlier work.

98. Fauna derSeen. 1. Seen der europaischen Turkei und Monte-
negros. II. Seen der Alpen Savoyens.
B. C., xviii, 169-73.
Review of Richard, 97, and Blanchard et Richard, 97.
ISTVANFFY, J.
*94. Ueber die Nahrung der Fischbrut im Balaton-See,
S.-B. k. Ungar. natw. Ges., Budapest, 19 Apr.
Cf. Bot. Centr., Ix, 172
JACKSON, D. D.
96. Onan Improvement in the Sedgwick-Rafter Method for the Mi-
croscopical Examination of Drinking Water.
Tech. Quar., ix, 271-4. 1pl.’ 1 table.
98. An Improved Filter for Microscopical Water Analysis.
Tech. Quar., xi, 241-5. 1 pl.

276 HENRY B. WARD:

JACKSON, D. D., AND Eins, J. W.
97: On Odors and Tastes of Surface Waters, with Special Reference
to Anabeena.
Tech. Quar., x, 410-20. 1 pl.
JANSEN, H.
*96. Der Miiggelsee in geographischer, biologischer und fischerei-
licher Beziehung. (Verh. 6. deutsch. Fischereitages, Berlin, 1896.)
Zeit. f. Fisch., iv, 268-301. 2 Karten.

JAWOROWSKI, A.
*93. Neue Arten der Brunnenfauna von Krakau und Lemberg.
(Czeckish; German résumé. )
Lemberg, 8°. 61 pp.

*96. Neue Arten der Brunnenfauna von Krakau und Lemberg.
Arch. f. Naturgesch., lxi, 1, 319-45. 1 taf.
Abst. J. R. M. S., 96, 301.

JELLIFFE, S. E.

93. The Chicago Water Supply in the World’s Fair Grounds.
Am. Mo. Mic. Jour., xiv, 310-1.
Abst. J. R. M. S., 94, 328.

93a. A Preliminary List of the Plants found in the Ridgewood Water
Supply of the City of Brooklyn, Kings County, N. Y.
Bull. Torrey Bot. Club, xx, 243-6.
Merely a faunal list.

*93b. A Preliminary Report on the Microscopical Organisms found in

the Brooklyn Water Supply.
Brooklyn Med. Jour., Oct. 93.

*94, A Further Contribution to the Microscopical Examination of
the Brooklyn Water Supply,
Brooklyn Med. Jour., Oct. 94.

JENNINGS, H. S.

94. A List of the Rotatoria of the Great Lakes and of Some of the
Inland Lakes of Michigan.
Bull. Mich. Fish Comm., 3, 1-34. 1 pl.
Rey. B. C., xiv, 494-5 (= Imhof, 94a, q. v.); Abst. J. R. M. S., 94, 574.
Systematic-faunistic.

96. Report on the Rotatoria. With Description of a New Species.
Bull. Mich. Fish Comm., 6, 85-93. 2 figs.
Systematic-faunistic.

98. Trochosphaera Again.
Science n. s., viii, 551.
Found at Put-in-Bay, O. Not abundant.

JUDAY, C.
97. The Plankton of Turkey Lake.
Proc. Indiana Acad. Sci., 96, 287-96. 1 map.

vib Or ait\

RECENT FRESHWATER INVESTIGATIONS 277

KELLICOTT, D. S.
96. The Rotifera of Sandusky Bay.
Proc. Am. Mic. Soc., xviii, 155-64.

97. The Rotifera of Sandusky Bay, II.
Trans. Am. Mie. Soc., xix, 43-54. 3 figs.
KERTESZ, K.
*94. The Rotiferfauna of Budapest and Vicinity (Czeckish).
Budapest. 55 pp. Rev. Z. C., iii, 234-7.

KLAPALex. FR.
*93. Untersuchungen tiber die Fauna der Gewasser Bbhmens.
I. Metamorphose der Trichopteren, II. Ser.
Arch. natw. Landesdurchf. Bohmens, viii, 6, 1-143. 38 figs.

KLEBABN, H.

95. Allgemeiner Charakter der Pflanzenwelt der Ploner Seen.
Forsch-ber. Biol. Stn. Plén, iii, 1-17.

96. Ueber wasserbliithebildende Algen und tiber das Vorkommen
von Gasvacuolen bei den Phycochromaceen.

Forsch-ber. Biol. Stn. Plon, iv, 189-206.
97. Bericht tiber einige Versuche betreffend die Gasvacuolen bei
Gloiotrichia echinulata.
Forsch-ber. Biol. Stn. Plon, v, 166-79.
KLUNZINGER, C. B.
*96. Ueber die biologische Station zu Ploén in Holstein.
Jahresh. Ver. vat. Naturk. Wiirtt., lii, 80-1.
*96a. Ueber das Sammeln von Auftrieb.
Jahresh. Ver. vat. Naturk. Wiirtt., lii, 124-5.

97. Die Lehre yon der Schwebewesen des stissen Wassers oder Unter-
suchungeweisen und Ergebnisse der Limnoplanktonologie mit
besonderer Riicksicht auf die Fischerei.

Zeit. f. Fisch., v, 120-70.
97a. Ferienstudien am Gardasee.
Jahresh. Ver. vat. Naturk. Wiirtt., liii, 51-3.

KNAUTHE, K.
96. Zur Biologie der Stisswasserfische.
B. C., xvi, 410-6.
98. Der Kreislauf der Gase in unseren Gewassern.
B. C., xviii, 785-805.
Kocus, W.
92. Versuche tiber die kiinstliche Vermehrung kleiner Crustaceen.
B. C., xii, 599-606; Zeit. f. Fisch., i, 157-63: Jahresh. rhein. Fisch.
Ver. 90-1,
KOENIKE, F.
95. | Nordamerikanische Hydrachniden.
Abh, naturw. Ver. Bremen, xiii, 167-226. 3 pl.
On a collection from Canada containing 30 species, 16 new.

¥ MD
ve ae

278 HENRY B. WARD:

Kororp, C. A.

96. A Report upon the Protozoa observed in Lake Michigan and
the Inland Lakes in the Neighborhood of Charlevoix, during the
Summer of 1894.

Bull. Mich. Fish Comm., 6, 76-84.
Fauna! list with notes.

96a. The Biological Experiment Station.
Illini, xxvi, 665-72, Figs.
96b. On the Occurence of Trochosphaera solstitialis in the Illinois
River.
Science, n. s., iv, 935-6.
At Havana, Il]. Perhaps imported by human agency.

97. Plankton Studies. I. Methods and Apparatus in use in Plank-
ton Investigations at the Biological Experiment Station of the
University of Illinois.

Bull. Ill. Lab. Nat. Hist., v, 1-25. 7 pl.
Rey. Nat. Sci., x, 365-7; Z. C., iv, 518.
97a. On Some Important Sources of Error in the Plankton Method.
Science, n. s., vi, 829-32.
Rev. Z. C., v, 159-60. «

98. Plankton Studies. II. On Pleodorina illinoisensis, 2 New

Species from the Plankton of the Illinois River.

Bull. Il. Lab. Nat. Hist., v, 273-93. 2 pl.
98a. Hints on the Construction of a Tow Net.

Jour. Appl. Mic., i, 111-3. 5 fig. Pt
98b. The Freshwater Biological Stations of America.

Am. Nat., xxxii, 391-406.

KRAMER, A.
97. Zur Mikrofauna Samoas.
FRY NEN een Is SB oy

Rey. Z. C., iv, 608. J. R.M. S., 97, 368.

LAKOWITZ, L.

96. Ein neues Horizontalschliessnetz.

Schr. Naturf. Ges. Danzig, ix, 275-9. 1 pl.
Rev. Z: C., v, 42.

LAMEERE, AUG.

*95. La faune des regions belgiques.

Feuille jeunes Nat., 3, xxvi, 58.

LAMPERT, K.

*93. | Bemerkungen zur Siisswasserfauna Wiirttembergs.
Jahresh. Ver. vat. Naturk. Wiirtt., xlix, 102-9
*96. | Das Thierleben unserer Seen im Winter.

Jahresh. Ver. vat. Naturk. Wiirtt., lii, 103-4.

97-8. Das Leben der Binnengewassser.
Leipsig, 8°. 12 parts. 560 pp. Pl. and text figs.

RECENT FRESHWATER INVESTIGATIONS 279

LANGENBECK,
*93. Ueber die Bildung der Sprungschicht in den Seen.
Petermann’s Mitth., xxxix.
LANKESTER, E. R.
938. Reappearance of the Freshwater Medusa (Limnocodium
Sowerbii).
Nature, xlix, 127-8
Transfer from place to place with tropical plants.
LARGE, THOS. :
97. Physical Survey of Lakes Tippecanoe, Eagle, Webster and
Cedar.
Proc. Ind. Acad. Sci., 96, 296-302 4 maps.

LAUTERBORN, R.
*93. Ueber Periodicitat im Auftreten und in der Fortpflanzung eini-
ger pelagischen Organismen des Rheins und seiner Altwasser.
Ver. Nat. Hist.-Med. Vereins, Heidelberg, n. F., v, 1.
94. Ueber die Winterfauna einiger Gewasser der Oberrheinebene.
Mit Beschreibungen neuer Protozoen.
B.C., xiv, 390-8.
Rey. Z. C., i, 465; J. R. M. S., 94, 440.
*94a. Beitrage zur Siisswasserfauna der Insel Helgoland.
Wiss. Meeresuntersuch., n. F., i, 217-21.
Rev. Z. C., ii, 102-3.
98. Ueber die zyklische Fortpflanzung limnetischer Rotatorien.
B. C,, xviii, 173-83.
*98a. Vorlaufige Mittheilung tiber den Variationskreis von Anuraea
cochlearis Gosse.
Z. A., xxi, 597-604. 6 fig. Abstr. J. R. M.S., 98, 39.
LEEDs, A. R.
97: Quantitative Estimation of Micro-Organisms.
Stevens’ Indicator, xiv, 31-44. 1 pl.
LEMMERMANN, E.
95. Verzeichniss der in der Umgegend von Pl6n gesammelten Algen.
Forsch-ber. Biol. Stn. Plon, iii, 18-67.
Fauna list.
96. Zur Algenflora des Riesengebirges.
Forsch-ber. Biol. Stn. Plon, iv, 88-133.
Systematic-faunistic study.
96a. Zur Algenflora des Ploner Seengebietes. Zweiter Beitrag.
Forsch-ber. Biol. Stn. Plén, iv, 134-88.
Systematic-faunistic study.

97. Resultate einer biologischen Untersuchung der Forellenteiche
von Sandfort.
Forsch-ber. Biol. Stn. Plon, v, 67-112. 2 fig. 1 plan.
Faunal list—discussion of value of different vegetation.

280 HENRY B. WARD:

98. Der grosse Waterneverstorfer Binnensee. Kine biologische
Studie.
Forsch-ber. Biol. Stn. Plon, vi, 167-204. 1 taf. Rev. Z. C.. v, 487.
LENDENFELD, R. VON.
96. | Neuere Arbeiten tiber die Tiere der Finsterniss.
Z. C., iii, 789-801, 821-7.
LEVANDER, K. M.
94, Kleine Beitrage zur Kenntniss des Thierlebens unter dicker
Eisdecke in einigen Gewassern Finnlands.
Meddel. Soc. Fauna Flora Fenn., xx, 6 pp.
Rey. Z. C., iii, 426
94a. Materialien zur Kenntniss der Wasserfauna in der Umgebung
von Helsingfors, mit besonderer Beriicksichtigung der Meeres-
fauna. 1. Protozoa.
Acta Soc. Fauna Flora Fenn., xii, 2, 1-115. 3 taf.
Rev. Z. C., ii, 632-33; J. R. M. S., 94, 462.
94b. Materialien zur Kenntniss der Wasserfauna in die Umgebung
von Helsingfors, mit besonderer Beriicksichtigung der Meeres-
fauna. II. Rotatoria.
Acta Soc. Fauna Flora Fenn., xii, 3, 1-72. 3 taf.
* Rey. Z. C.. ii, 754-6.
LINSBAUER
*95. Vorschlag einer verbesserten Methode zur Bestimming der
Lichtverhaltnisse im Wasser.
Verh. K. K. Zool-bot. Ges. Wien, 95.

LORENZ VON LIBURNAU, JOS.

*98. Der Hallstatter See. Eine limnologische Studie.
Mitth. geogr. Ges. Wien.. xli, 1-218.
LORENZI, A.

*96. Una visita al laghetto di Cima Corso (Ampezzo).
Alto Croan. Soc. Alp. Friulana., vii, 10 pp. Rev. Z. C., iv, 52.
*97, La fauna dei laghi del Friuli.
Alto Croan. Soc. Alp. Friulana, vii. 6 pp.
Rev. Z. C., v, 487-8.
#98. Prime osservazioni zoologiche sulle acqua freatiche del Friuli.
Alto Croan. Soc. Alp. Friulana, ix. 9 pp.
Rev: ZC, Vv. vou
Subterranean waters. New species of Niphargus.
LUNDBERG, R.
*95. On the Postembryonal development of the Daphnids.
Bih. Kg. Svens. Vet. Ak. Handl., xx, 4,2. 19 pp. 2 pl.
Rev. J. M. R. S., 96, 418.
MAGNIN, A.
*95. Les Lacs du Jura. 1, Généralités sur la pee jurassienne
2, Végétation des lacs du Jura suisse.
Paris et Lyon, 8°, 96 and 23 pp., 1 and 2 pl., 17 ali 5 text-fig.

RECENT -FRESHWATER INVESTIGATIONS 281

Marsp, C. D.
94. On the Vertical Distribution of Pelagic Crustacea in Green Lake,
Wisconsin.

Am. Nat. xxviii, 807-9. Abst. J. R. M.&., 95, 311-2.

95. On the Cyclopidae and Calanidae of Lake St. Clair, Lake Mich-
igan, and certain of the Inland Lakes of Michigan.
Bull. Mich. Fish Comm., 5, 1-24, 9 pl.
Abst. J. R. M. S., 96, 414.
Systematic-faunistic.

97. On the Limnetie Crustacea of Green Lake.
Trans: Wis. Acad. Sci., xi, 179-224, 10 pl.
Abst. J. R. M. S., 97, 534.

McMItLian, C.
93. The Gull Lake Biological Station of the University of Minne-
sota.
Science, xxi, 330.

Mez, C.

*98. Mikroskopische Wasseranalyse. Anleitung zur Untersuchung
des Wassers mit besonderer Beriicksichtigung von Trink- und
Abwasser.

Berlin, 8°. 631 pp., 8 Taf., 38 text-fig.
Rey. B. C., xviii, 507-9; Z. C., v, 446-7.

Mreura, W.
*94. Methode und Aufgabe der biologischen Wasseruntersuchung.
Jahresb. Ver. Naturk. Manneim, 1, 20, 1-59.

MOENKHAUS, W. J.
98. Material for the Study of the Variation of Htheostoma capro-
des Rafinesque and Etheostoma nigrum Rafinesque in Turkey
Lake and Tippecanoe Lake.
Proc. Ind. Acad. Sci., 97, 207-228.
Adjacent lakes in different water-basins compared.

MontTGomeEry, T. H., Jr.
95. Stichostemma Eilhardin.g. et n. sp. Ein Beitrag zur Kenntnis
der Nemertinen.
Zeit. f. wiss. Zool., lix, 83-146, 2 Taf. Rev. Z.C., ii, 146-9.
Detailed study of the structure of a freshwater nemertine.

95a. The Derivation of the Freshwater and Land Nemerteans, and
allied Questions.
Jour. Morph., xi, 479-484.
Rev. Z. C., iii, 142-3.

96. Stichostemma asensoriatum u. sp.,a Freshwater Nemertean
from Pennsylvania.
Z. A., xix, 436-8. Abst. J. R. M. S., 97, 38.
Includes brief review of American freshwater species.

282 HENRY B. WARD:
Moore, J. E. S.
*97. On the General Zoological Results of the Tanganyika Expedi-
tion.

Proc. Zool. Soc., London, 97, 436-9.

97a. The Freshwater Fauna of Lake Tanganyika.
Nature, lvi, 198-200, 2 fig.

97b. The Fauna of the Great African Lakes.
Sci. Progress, vi, 627-41.

98. On the Zoological Evidence for the Connection of Lake Tangan-
yika with the Sea.
Proc. Roy. Soc. London, lxii, 451-8. 3 fig.

98a. The Mollusks of the Great African Lakes. 1. Distribution.
Quar.Jour. Mic. Sci., xli, 159-180.

98b. On the Hypothesis that Lake Tanganyika represents an Old
Jurassic Sea.
Quar. Jour. Mic. Sci., xli, 303-21. 1 pl.

98c. The Marine Fauna in Lake Tanganyika and the Advisability of
further Exploration in the Great African Lakes.
Nature, lviii, 404-8.

Moors, J. P.

98. The Leeches of the U. S. National Museum.
Proc, U. S. Nat. Mus., xxi, 543-63. 1 pl.
Valuable taxonomic study on North American forms.

MRAzEK, A.
*93. Beitrage zur Kenntniss der Siisswassercopepoden (Czeckish).
Vestnik spol., Prag, 98. 74 pp. 3 pl.
Rey. Z. C., i, 593-4; J. R. M. S., 95, 52.

MRAZEK, A.
*93a. Beitrag zur Kenntnis der Harpakticidenfauna des Siisswassers.
Zool. Jahrb., Syst., vii, 89-130. 4pl. Rev. Z. C., i, 277.
*95. Copepoden. Deutsch-Ost-Afrika.
Wiss. Forsch-res., iv, 11 pp., 3 pl.
MULLER, O.
98. Bacillariales aus den Hochseen des Riesengebirges.
Forsch-ber. Biol. Stn. Plén, vi, 48-87. 3 pl.

NACHTRIEB, H. F.
94. Zoological Work during 1893 at the Gull Lake Biological Sta-
tion.
Quar. Bull. Univ. Minn., ii, 5-7.

NoBRE, AUG.
*94.___ Estudos sobre a fauna aquatica dos rios do norte de Portugal.
Annaes sci. nat., Porto, i, 151-7.
Merely a faunal list.

NORDENSKIOLD, E.
97. Notizen tiber Hydrachniden aus Siid-Finland.
Acta Soc. Faun. Flor. Fenn., xv, 1, 1-8.
Occurrence, distribution.

¥
“ue Hee:

RECENT FRESHWATER INVESTIGATIONS 28

pa)

OLIVIER, E.
*94. Les Lacs d’ Auvergne.
Rey. Sci. Bourbonn., vii, 117-9.
PACKARD. A. 8.
94. On the Origin of the Subterranean Fauna of North America.
Am. Nat., xxvili, 727-51. 2 pl.
Rev. Z. C., ii, 137-9.
PERO, P.
*93. I laghi alpini valtellinesi. Parte I. Valle dell’ Adda.
Nuova Notarisia, iv.
*93a. I laghi alpini valtellinesi. Parte Il. Valle del Liro (Splugia).
Nuova Notarisia, iv, 117.
*93b. Richerche e studi sui laghi valtellinesi.
Nuova Notarisia, iv, 248-; 301-.
*94. —‘ I laghi alpini valtellinesi.
Nuova Notarisia, v, 413-; 670-.
FD. Cenni oroidrografici e studio biologico del lago di Mezzola.
Malpighia, ix, 71-112; 235-9.
95a. I laghi alpini valtellinesi. Fine.
Nuova Notarisia, vi, 1-18. 1 table. 1 map.
PETR, FR.
. *94, Freshwater Sponges of Europe (Czeckish).
Gymnas. program, Chrudim, 32 pp. 2pl. Rev. Z. C., ii, 301-2.
PIERSIG, R.
97. Deutschlands Hydrachniden.
Bibl. Zool. 22. (Not yet completed.)
Rev. Z. C., iv, 487-9.
Monograph of group with frequent important references to
habitat in freshwater.
PIETERS, A. J.
94. The Plants of Lake St. Clair.
Bull. Mich. Fish Comm., 2, 1-10. 1 map.
Faunistic. Distinguishes aquatic plant formations.
PITARD, HuG.
#96. Sur le Plankton des lacs du Jura.
C. R. Soc. Helv. Se. Nat., xx)xi, 152-5.
*96a. Le Plankton des lacs du Jura.
Arch. se. phys. et nat. Genéve, 4, ii. 4 pp.
Rev. Z. C., iv, 375-6.
We La répartition quantitive en surface du Plankton.
Arch. se. phys. et nat. Genéve, 4, iii, 64-6. Rev. Z. C., iv, 513.
97a. Sur le Plankton du lac de Chavonnes.
Arch. se. phys. et nat. Genéve, 4, iii, 67-70. Rev. Z. C., iv, 513.
97b. Le Plankton du Lac de Lowerz.
Arch. se. phys. et nat. Genéve, 4, iii, 77-9. Rev. Z. C., iv, 513.

» Pk Pos Ue ae
PIRI

984 HENRY B. WARD:

97c. Sur le plankton du lac de Joux.
Arch. sc. phys. et nat. Genéve, 4, iii, 79-81. Rev. Z. C., iv, 514.

97d. Sur le plankton du lac de Brenet.
Arch. se. phys. et nat. Genéve 4, iii, 81-8. Rev. Z. C., iv, 514.

PLESSIS, G. DU.
*93. Organization et genre de vie de |’ Hmea lacustris, Nemertien
des environs de Geneve.
Rey. Suisse zool., i, 329-57. 1 pl.
95. Note sur l’importation des Némertiens dans les eaux douces.
Z. A., xviii, 495-8. Rev. Z. C., iii, 148.

Poppe, S. A. UND MRAZEK, W.
*95. Die von Herrn Dr. F. Stuhlmann auf Zanzibar und dem gegen-
iiberliegenden Festlande gesammelten Siisswasser-Copepoden.
Jahrb. Hamburg. wiss. Anst., xii (Beiheft), 125-34. 2 pl.

*95a. Entomostraken aus Siid-Georgien.
Jahrb. Hamburg. wiss. Anst., xii (Beiheft), 135-8. 1pl.

*95b. Die von Herrn Dr. H. Driesch auf Ceylon gesammelten Siss-
wasser-Entomostraken.
Jahrb. Hamburg. wiss. Anst., xii (Beiheft), 139-42. 1 pl.
Puenat, C. A.
97. Premiére contribution a ]’étude de la faune des lacs de la Savoie.
Revue Savois., 97,9 pp. Rev. Z. C., iv, 469.
REIGHARD, J. E.
93. A Laboratory on the Great Lakes.
Z. A., xvi, 399-401.
94. Some Plankton Studies in the Great Lakes.
Bull. U. S. Fish Comm., xiii, 127-42. 2 pl.

94a. A Biological Examination of Lake St. Clair.
Bull. Mich. Fish Comm., 4, 1-41. 2 pl. 1 map.
Rev. Z. C., ii, 7-8; cf. Nat. Sci., x, 8-9.
94b. Suggestions for an Experimental Method of Determining the
Efficiency of Quantitive Nets.
Bull. Mich. Fish Comm., 4, 57-60.
98. Methods of Plankton Investigation in their Relation to Prac-
tical Problems.
Bull. U. S. Fish Comm., xvii, 169-75.
RICHARD, J.
+ *93. Copépodes recueillis par. M. le Dr. Th. Barrois en Egypte, en
Syrie, et en Palestine.
Rey. Biol. Nord France, v, 10. 36 pp. 51 fig.
93a. Sur la distribution géographique des Cladocéres.
C. R. Congress Int. Zool., Moscou 1892. 9 pp.
~ 94. Revision des Cladocéres, I.
Ann. Sci. Nat., zool., xviii, 279-389. 2 pl.

*94a,

96c.

=O.

*97a.

97b.

98.

RECENT FRESHWATER INVESTIGATIONS 285

Cladocéres recueillis par le Dr. Th. Barrois en Palestine, en
Syrie et en Egypte.
Rey. Biol. Nord France, vi, 360-79. 12 fig.

Sur quelques animaux inférieurs des eaux douces du Tonkin.
Mém. Soe. Zool. France, vii, 237-48.
Rey. Z. C., i., 810.

Entomostracés recueillis par M. E. Modigliani dans le lac Toba
(Sumatra).
Ann. Mus. Civ. Genova, 2a, xiv, 565-78.

Cladocéres et Copépodes recueillis par M. Kavraisky prés de
Tiflis et dans le lac Goktsha.
Bull. Soe. Zool. France, xx, 91-3.

Sur quelques Entomostracés d’eau douce d’Haiti.
Mém. Soc. Zool. France, viii, 189-99. 11 fig.

Contribution 4 la faune des Entomostracés de la France.
Feuille Jeun. Naturl., 3, xxv, 9 pp. 6 fig. Rev. Z. C., iii, 322.
Fauna! list.

Revision des Cladocéres, II.
Ann. Sci. Nat., zool., 8, ii, 187-368. 6 pl.

Sur la faune pélagique du Tegernsee.
Z. A., Xix, 28-9.
Rev. Z. C., iii, 189-40.
Sur la faune des eaux douces des Acores.
Bull. Soe. Zool. France, xxi, 171-8.
Abst. J. R. M. S., 97, 26; Z. C., iv, 469.
New forms reported; only cosmopolitan species.
Sur la faune de quelques lacs élevés du Caucase d’aprés les
récoltes de M. Kavraisky.
Bull. Soc. Zool. France, xxi, 183-5.
Abst. Z. C., iv, 469-70.

Entomostracés recueillis par M. le Directeur Steindachner dans
les lacs de Janina et de Scutari’.

Ann. Nat. Hofmus. Wien, xii, 63-6. 1 fig.

Rev. Z. C., iv, 848.

Pelagic fauna poor, of 5 species, one new.

Sur quelques Entomostracés d’eau douce des environs de Buenos
Aires.
Anal. Mus. nac. Buenos Aires, v, 821-32. 6 fig.
Rev. Z. C., iv, 843.

Entomostracés de l’Amérique du Sud, recueillis par MM. U.
Deiters, H. v. Jhering, G. W. Miller, et C. O. Poppe.
Mém. Soc. Zool. France, x, 263-301. Rey. Z. C., iv, 842-3.
Sur la faune des eaux douces des iles Canaries.
C. R. Ac. Sci. Paris, exxvi, 439-41,
Rey. Z. C., v, 352.

286 HENRY B. WARD:

98a. Sur la faune des eaux douces explorées en 1898 pendant la cam-
pagne du yacht ‘‘ Princesse Alice.’’ i
Mém. Soc. Zool. France, xi, 326-38.
RICHTER, P.
94, Gloiotrichia echinulata P. Richt., eine Wasserblitite des Grossen
und Kleinen Ploner Sees.
Forsch-ber. Biol. Stn. Plon, ii, 31-46.

RizzARpI, U.

*94. Risultati biologici di una esplorazione del lago di Nemi.
Boll. Soe. Rom. stud. zool., 3, iii, 137-57.
Rey. Z. C., ii, 195.

*96. Gli Entomostraci del lago di Mezzola.
Boll. Soe. Rom. stud. zool., 8, v, 126-9.
Abstr. J. R. M.S., 97, 124.
Appendix to Pero, 95, q. v. Limnetic species few.

Ross, L. S.

96. Preliminary Notes on the Iowa Entomostraca.
Proc. Iowa Acad. Sci., 95, iii, 170-3.
Faunal list.

97. | Some Manitoba Cladocera with Description of one New Species.
Proc. Iowa Acad. Sci., iv, 154-62.
Systematic-faunistic.

97a. A New Species of Daphnia and Brief Notes on Other Cladocera
of Iowa.
Proc. Iowa Acad. Sci., iv, 162-6. 2 fig.

97b. The Illinois Biological Station.
Proc. Iowa Acad. Sci., iv, 167-70.
RussELL, I. C.
95. Lakes of North America.
Ginn & Co., Boston. 125 pp. 8 fig. 23 pl.
Sars, G. O.
*94. Contributions to the Knowledge of the Freshwater Entomos-
traca of New Zealand.
Vid.-Selks. Forh. Christiania, 94, 5. 62 pp. 7 pl.
#95. On Some South African Entomotraca raised from dried mud.
Vid.-Selks. Forh. Christiania, 95,8, 1-56. 8 pl.

*96. On Freshwater Entomostraca from the Neighborhood of

Sidney.
Arch. Math. Natw., xviii, 2, 1-81. 8 pl.

ScHacat, F. W.

97. |The North American Species of Diaptomus.

Bull. lll. Lab. Nat. Hist., v, 97-207. 15 pl.
Rev. Z. C., v, 227.
Taxonomic; data on distribution, seasonal variations; bibliography.

98.

RECENT FRESHWATER INVESTIGATIONS 287

The North American Centropagidae belonging to the Genera
Osphranticum, Limnocalanus and Epischura.
Bull. Ill. Lab. Nat. Hist., v, 225-69.
Rev. Z. C., v, 7138-4; Am. Nat., xxxiii, 164-5.
Systematic-faunistic with valuable bibliography.

ScCHAREFF, R. F.

*95.

On the Origin of the Land and Freshwater Fauna of Ireland.
Proc. R. Irish Acad., 3, iii, 479-85.
Rev. J. R. M. S., 95, 161; Nat. Sci., vi, 147-8.

SCHAUDINN, F.

96.

Heliozoa. Das Tierreich, 1-24.
Abstr. J. R. M. S., 96, 427.
Systematic.

SCHEWIAKOFF, W.

*93. Ueber einige ekto- und entoparasitiche Protozoen der Cyclo-
piden.
Bull. Soc. Imp. Nat. Moscou, 93, 1, 1-29. 1 taf.
Rey. Z. C., i, 8-9.
Description of tycholimnetic species.
93a. Ueber die geographische Verbreitung der Stisswasser-Proto-
zoen.
Mém. Ac. Imp. Se. St. Pétersbourg, 7, xli, 8, 201 pp. 4 taf.
Rev. Z. C., i, 813-5; J. R. M. S., 95, 321-2.
SCHMEIL, O.
$2. Deutschlands freilebende Siisswasser-Copepoden. I. Cy-
clopidae.
Bibl. Zool., 11, 192 pp. 8 pl.
93. _Deutschlands freilebende Stisswasser-Copepoden. II. Harpac-
ticidae.
Bibl. Zool., 15, 103 pp. 8 pl.
Rev. Z. C., i, 278.
*93a. Copepoden des Rhatikon Gebirges.
Abh. naturf. Ges. Halle, xix.
*94. Zur Hohlenfauna des Karstes.
Zeitsch. f. Naturwiss., lxvi, 339-53.
Rey. Z. C., i, 464-5; also iii, 790-801.
96. | Deutschlands freilebende Siisswasser-Copepoden. III. Centro-
pagidae.
Bibl. Zool., 21. 144 pp. 12 pl.
Rev. Z. C., iv, 65-8; J. R. M. S., 96, 522-3.
98. Deutschlands freilebende Siisswasser-Copepoden. Nachtrag.

Bibl. Zool., 21, 145-88. 2 Taf.
Rey. Z. C., iv, 841-2.

288 HENRY B. WARD:

SCHRODER, B.

97. Die Algenflora der Versuchsteiche.
Forsch-ber. Biol. Stn. Plén, v, 29-66. 3 pl.
Systematic-faunistic.

97a. Ueber das Plankton der Oder.
Ber. Deutsch. Bot. Ges., xx, 482-92. 1 pl.

98. Neue Beitrage zur Kenntnis der Algen des Riesengebirges.
Forsch-ber. Biol. Stn. Plon, vi, 9-47.

98a. Planktologische Mittheilungen.
B. C., xviii, 525-35.
SCHRODER, B. UND ZACHARIAS, O.
*97. | Ueber die Flora und Fauna der Versuchsteiche des Schlesischen
Fischerei-Vereins zu Trachenberg in Schlesien.
1. Die Vegetationsverhaltnisse der Versuchsteiche, B. Schréder,

p. 28-36.
2. Die Fauna des Versuchsteiche, O. Zacharias, p. 36-51.

Zeit. f. Fischerei, v, 28-40; 41-51. 11 fig.
SCHROTER, C.
‘OT; Schwebeflora unserer Seen. Das Phytoplankton.
Neujahrsblatt naturf. Ges. Ziirich, xcix, 60 pp. 3pl. 3 fig.
Rey. B. C., xvii, 209-12; Arch. sci. phys. et nat. Genéve, 3, iii,
577-8.
SCHROTER, C., UND KIRCHNER, O.
*96. Die Vegetation des Bodensees.
Bodensee-Forschungen, ix. Absch. Lindau i’ B.
Rev. B. C., xvii, 5938-9.
Scott, A. AND T.
*95. On New and Rare Species of Copepoda from Scotland.
Annals Scot. Nat. Hist., No. 13, 28-35. 1 pl.
*95a. Notes on Some Rare Freshwater and Marine Copepoda from

Scotland.
Annals Scot. Nat. Hist., No. 16, 233-9. 1 pl.
Scort, T. 7
93. The Invertebrate Fauna of the Inland Waters of Scotland.
Part III.

Ann. Rept. Fish Bd. Scotland, xi, 220-88. 2 pl.

*94. The Invertebrate Fauna of the Inland Waters of Scotland.
Part IV.
Ann. Rept. Fish Bd. Scotland, xii, 284-90.

95. The Invertebrate Fauna of the Inland Waters of Scotland.

Part VY.
Ann, Rept. Fish Bd. Scotland, xiii, 237-57. 2 pl.

*95a. Notes on Freshwater Entomostraca with Special Reference to

Loch Leven.
Annals Scot. Nat. Hist., No. 15, 163-178.

96.

9%.

98.

RECENT FRESHWATER INVESTIGATIONS 289

The Invertebrate Fauna of the Inland Waters of Scotland.
Part VI. :
Ann. Rept. Fish Bd. Scotland, xiv, 167-70.
Rev. Z. C., iv, 376.
Faunal lists of several lakes and comparison of the same.

The Invertebrate Fauna of the Inland Waters of Scotland.
Part VII.
Ann. Rept. Fish Bd. Scotland, xv, 316-27. 1 pl.
Rey. Z. C., v, 160.
Comparison of nine Scotch lakes with faunal lists and descrip-
tions.

The Invertebrate Fauna of the Inland Waters of Scotland.
Part VIII.
Ann. Rept. Fish Bd. Scotland, xvi, 248-52. 4 pl.

Scott, T., AND DuTHIE, R.

95.

96.

97.

98.

The Inland Waters of the Shetland Islands,
Ann. Rept. Fish Bd. Scotland, xiii, 174-91. 1 pl.
The Inland Waters of the Shetland Islands. Part II.
Ann. Rept. Fish Bd. Scotland, xiv, 229-48. 1 pl.
Rev. Z. C., iv, 376.
An examination of numerous bodies of water; fauna scanty, in-
teresting.
An Account of the Examination of some of the Lochs of Shet-
land.
Ann. Rept. Fish Bd. Scotland, xv, 327-38.
Rev. Z. C., v, 160.
Further studies show anincrease on previous list of species.
Account of the Examination of some of the Lochs of Shetland.
Ann. Rept. Fish Bd. Scotland, xvi, 253-60.

‘ SCOURFIELD, D. J.

93.

*=94.

95.

*96.

97.

97a.

The Entomostraca of Wanstead Park.
Jour. Quekett Mic. Club, 2, v, 161-78.
Abst. J. R. M. S., 94, 567.

Entomostraca and the Surface-film of Water.
Jour. Linn. Soc. London, xxv, 158, 1-19. 2 pl.
Abst. J. R. M. S., 95, 52.
A Preliminary Account of the Entomostraca of North Wales.
Jour. Quekett Mic. Club, 2, vi, 127-48. 1 pl.
Rey. Z. C., iii, 462.
No macrofauna; poor littoral, rich limnetic microfauna.
On the Necessity for a British Freshwater Station.
Rep. Brit. A. A. 8. Liverpool, lxvi, 831-2.
Wanted, a British Freshwater Biological Station.
Nat. Sci., x, 17-9; ef. viii, 8-9.
The Logarithmic Plotting of Certain Biological Data.
Jour. Quekett Mic. Club, 2, vi, 419-23. 1 pl.
1

Se

290 . HENRY B. WARD:

97b. Contributions to the Non-Marine Fauna of Spitzbergen.
Proc. Zool. Soc. Lond., 97, 784-92. 1 pl.
97c. Verzeichniss der Entomostraken von Plén.
Forsch-ber. Biol. Stn. Plén, v, 180. 1 tab.
Fauna list.
98. The Entomostraca of Epping Forest. Part I.
Essex Nat., x, 193-210.
98a. The Entomostraca of Epping Forest. Part II.
Essex Nat., x, 259-74. 3 tables.
9Sb. The Entomostraca of Epping Forest. Part III and IV.
Essex Nat., x, 313-34.
Rev. Am. Nat., xxxiii, 161-2.

SEKERA, E.

*98, Studie limnobiologicke.
. Program Gymnas., Pilgram, Bohemia. 28 pp.
SELIGO, A.

*93. Ueber einige Flagellaten des Siisswasserplankton.

Festgabe Westpr. Fisch. Ver. z. d. 150 jar. Jubil.
Naturf. Ges. Danzig.
97. Zur Wasserpestfrage.
Allg. Fisch.-Zeit., xxii, 19-20. 7 pp.
SERNow, N.
97. Daily Variations in the Plankton Volumes in Deep Lake (Rus-
sian).
Arb. Ichth. Sect. k. Acclim. Ges., ii, 210.
Table of amounts; ef. Zograf, 97.
SEuRAT, L. G.
*98 Sur la faune des lacs et lagunes du valle de Mexico.
Bull. Mus. Hist. Nat. Paris, 98, 28-7.
SHARPE, R. W.
$7. Contribution to a Knowledge of tae North American Fresh-
water Ostracoda included in the Families Cytheridae and Cy-
prididae. (With an extensive bibliography).
Bull. Ill. Lab. Nat. Hist., iv, 414-84. Pl. 39-48.
Rey Z. C., iv, 527-8.
SimrortuH, H.
*96. Ueber Landpfianzen und Landthiere im heimischen Stisswasser.
Mitth. a. d. Osterlande, n. F., vii, 105-25.
Rev Z. C., iv, 509-12.
SmitH, F.
94. — List of the Protozoa and Mollusca observed in Lake St. Clair in
the Summer of 1893.
Bull. Mich. Fish Comm., 4, 42-4.
Faunistic.

RECENT FRESHWATER INVESTIGATIONS 291

SmirH, H. M.
98. Biological Survey of Lake Erie.
Science, n. s., viii, 13-4. ~
Smita, J. C.
97. Notices of Some Undescribed Infusoria, from the Infusoria]
Fauna of Louisiana.
Trans. Amer. Mic. Soc., xix, 55-68. 1 pl.
Soar, C. D.
97. Presidential Address: a few words on Water-mites.
Journ. Micros. and Nat. Sci., vii, 12 pp.
Contains notes on occurrence, means of collecting, etc.
STECK, TH.
93. Beitrage zur Biologie des grossen Moosseedortsee’s.
Mitt. Naturf. Ges. Bern, 93, 20-73, 1 pl.

STENROOS, K. E.
95. Die Cladoceren der Umgebung von Helsingfors.
Acta Soc. Faun. Flor. Fenn., xi, 2, 1-44. 1 pl.
Rev. Z. C., iii, 324.

97. Zur Kenntniss der Crustaceenfauna von Russisch-Karelien.
Acta Soc. Faun. Flor. Fenn., xv, 2, 1-72, 1 pl. 1 chart, 1 table.
98. Das Thierleben im Nurmijarvi-See.

Acta Soc. Faun. Flor. Fenn., xvii, 1, 1-259, 3 pl. 1 ch.
Rey. Z. C., v, 603-6; Am. Nat., xxxii, 793-4.

STEUR, A.
*97. | Copepoden und Cladoceren des siissen Wassers aus der Umge-
bung von Triest.
Verh. kk. zool.-bot. Ges. Wien, 97, 16 pp. 1 taf.

*97a. Kin Beitrag zur Kenntniss der Cladoceren und Copepoden-
fauna Karntens.
Verh. kk. zool-bot. Ges. Wien, 97, 49 pp. 6 fig.

STINGELIN, TH.
95. Ueber die Cladocerenfauna der Umgebung von Basel.
Z. A., xviii, 49-51. (Preliminary).
Abst. J. R. M. S., 95, 426.
*95a. Die Cladoceren der Umgebung von Basel.
Rev. Suisse Zool., iii, 161-274. 4 pl.
Rey. Z. C., iii, 322-4; J. R. M. S., 96, 62.

97. Ueber jahreszeitliche, individuelle und locale Variation bei
Crustaceen, nebst einige Bemerkungen tiber die Fortpfianzung
bei Daphniden und Lynceiden.

Forsch-ber. Biol. Stn. Plon, v, 150-65, 5 text fig.
Rey. Z. C., iv, 625-6.
STOCKMAYER, O.

94. Das Leben des Baches (des Wassers tiberhaupt).

Ber. Deutsch. Bot. Ges., xii, (Appendix) 133-41.

ii a ‘
itn,

999 ; HENRY B. WARD:

SToKEs, A. C.
96. Aquatic Microscopy for Beginners. |
Portland, Conn., 3d Ed., 326 pp. 198 text-fig.

STRODTMANN, S.
95. Die Ursache des Schwebvermdzens bei den Cyanophyceen
(vorlaufige Mitth.). ;
B. C., xv, 113-5.
*95a. Die Anpassung der Cyanophyceen an das pelagische Leben.
Arch. Entw-mech. Organismen, i, 3.

95b. Bemerkungen iiber die Lebensverhaltnisse des Siisswasser
plankton.
Forsch.-ber. Biol. Stn. Pl6én, ili, 145-79.

96. Planktonuntersuchungen in holsteinischen und mecklenbur-
gischen Seen.
Forsch-ber. Biol. Stn. Plon, iv, 273-87.
Rey. Z. C., iii, 447-8.

97. Ueber die Nahrung einiger Wildfische.
Zeit. f. Fischerei, v, 103-12.
98, Ueber die vermeintliche Schadlichkeit der Wasserbliite.

Forsch-ber. Biol. Stn. Plén, vi, 206-12.

StruvEr, TH.
*93. | Faune du lac de Champex.
Arch. se. phys. et nat. Genéve, 3, xxx, 151-8. Rey. Z. C., i, 214
Pelagic fauna little developed. List of forms observed. —

SuUNDVIK, E. E.
*96. Bidrag till fragan om fiskarnas resp. de kallblodiga djurens
O6fvervintring. (German resumé).
Meddel. Soc. Fauna Flora Fenn., 21, 12-4.
Rev. Z. C., iv, 51-2.

97. Beitrage zur Kenntniss der Infusorien Béhmens. I. Die cilia-
ten Infusorien des Unterpocernitzer Teiches.
Bull. Internat. Acad. Sci. Bohéme, 97,19 pp. 2 pl.

SzicETuy, K.
97. Die Fauna des Balatons. III. Turbellarien.
Result. wiss. Erforsch. Balatonsees, ii, 1, 73-9.
Faunistic-systematic.

Tuomas, Fr.
"07. Ein neuer durch Euglena sanguinea erzeugter, kleiner Blutsee
in der baumlosen Region der Biindner Alpen.
Mitth. Thiring. Bot. Ver., n. F. x, 28-34.
Rev. Z. C., iv, 778.
Sma.l pool, 2160 m. alt., blood red with Euglena.

RECENT FRESHWATER INVESTIGATIONS 293

THomeson, H. D.
96. A Biological Examination of Lake Michigan. The Aquatic
Plants.
Bull. Mich. Fish Comm., 6, 72-5.
Faunal list with notes.

TURNER, C. H.
93. Additional Notes on the Cladocera and Ostracoda of Cincin-
nati, Ohio.

Bull. Sci. Lab. Denison Univ., viii, 1-18, 2 pl.
94. Notes on American Ostracoda with Description of New Species.
Bull. Sci. Lab. Denison Univ., viii, 2, 13-26. 2 pl.

ULE, W.

*93. Die Temperaturverhaltnisse der baltischen Seen.
Verh. x. deutsch. Geographentages, Stuttgart.

*91. Beitrage zur Instrumentenkunde auf dem Gebiete der Seen-
forschung.
Petermann’s Mitth., xl.

94a. Geologie und Orohydrographie der Umgebung von Plén.
Forsch-ber. Biol. Stn. Plon, ii, 1-19.

VANGEL, E.
97. Die Fauna des Balatons. II. Coelenterata. Schwamme und
Hydren.

Result. wiss. Erforsch. Balatonsees, ii, 1, 65-71.
Faunistic-systematic.
97a. Die Fauna des Balatons. VI. Moosthiere (Bryozoa).
Result. wiss. Erforsch. Balatonsees, ii, 1, 135-43.
Faunistic-systematic.
97b. Die Fauna des Balatons. VII. Gliederwiirmer (Annelides).
Result. wiss. Erforsch. Balatonsees, ii, 1,. 145-51.
Faunistic-systematic.
VAVRA, W.
*93. Ein Beitrag zur Kenntniss der Siisswasserfauna von Bulgarien.
S.-B. K. Béhm. Ges. Wiss., Math.-natw. K1., xlvi, 4 pp.
Rev. Z. C., i, 898.
Numerous species of cosmopolitan character.
as Die Siisswasser-Ostracoden Deutsch-Ost-Afrikas.
Ostafrika, iv, 28 pp. 59 fig.
Rev. Z. C., iv, 486-7.
Faunal study. Most forms known, yet not reported from Africa.

98. Stisswasser-Ostracoden der Hamburger Magalhaenischen Sam-
melreise.
Hamburg. 1-26 pp. 5 fig.
VEJDOVSKEY, FR.
95. Zur vergleichende Anatomie der Turbellarien. (Zugleich ein
Beitrag zur Turbellarien-Fauna Bohmens. )
Zeit. f. wiss. Zool., 1x, 90-162, 4 pl; 163-214. 3 pl.

WS
294 HENRY B. WARD:
VESCOVIE, P. DE.
*9§. Notizie sulla formazione di un nuova lago nella provincia di
Roma e Considerazioni da punta di vista della fauna lacustre.
Boll. Soe. Rom. Stud. zool., v, 55-71.
Virée, A.
*95. Sur quelques animaux habitants les cavernes du Jura.
Bull. Mus. Hist. Nat. Paris, 95, 248-5.
*96. Animaux cavernicoles.
Bull. Mus. Hist. Nat. Paris, 96, 90-2; also note p. 139.
96a. Modifications apportées aux organes de relation et de la nutri-
tion chez quelques Arthropodes par le séjour dans les cavernes.
C. R. Acad. Sci., exxii, 486-7. ‘I'rans. Ann. Mag. Nat. Hist.,
xvii, 407-8.
Rev. Z. C., iii, 321-2, 790.
*97. La faune obscuricole des conduits d’eau de Seine de la ville de
Paris et le projet de dérivation des sources du Lunai.
Bull. Mus. Hist. Nat. Paris, 97, 237-42.
VoiactT, W.
*95. Ueber Thiere die sich vermuthlich aus der Eiszeit her in un-
seren Bachen erhalten haben.
Verh nath. Ver. preuss. Rheinl., lii, 235-44.
Rev. Z. C., iv, 340-1.
*Y6. Planaria gonocephala als Eindringling in das Verbreiterungs-
gebeit von Planaria alpina and Polycelis cornuta.
Zool. Jarb., Syst., viii, 131-76. 3 karten,
96a. Die Einwanderung der Planariaden in unsere Gebirgsbache.
Verh. nath. Ver. preuss Rheinl., liii, 103-48. 1 pl.
Voz, W.
98. Ueber neue Turbellarien aus der Schweiz (vor]. Mitth.).
Z. A., xxi, 605-12. Figs.
WAGNER, PAUL. 5
#97, Die Seen des Boéhmerwaldes. Eine geologisch-geograpische
Studie; zugleich ein Beitrag zur Lésung des Karproblems.
Leipzig.
*97a. Fishfang im Gardasee.
Die Natur, xlvi, 616-7.
WALKER, B.
95. A Month with the Michigan Fish Commission.
Nautilus, xi, 2-6.
Description of the molluscan fauna.
95a. Review of our Present Knowledge of the Molluscan Fauna of
Michigan. Detroit. 27 pp.
96. |Report upon the Moliusca Collected in the Vicinity of Charle-
voix, Michigan, in the Summer of 1894.
Bull. Mieh. Fish Comm., 6, 96-9.
Faunal list with notes.
749 tlh

RECENT FRESHWATER INVESTIGATIONS 295

WALTER, E.
93. Biologie und Biologische Stsswasserstationen.
Forsch-Ber. Biol. Stn. Pl6on, ii, 188-47.
95. Eine praktisch-verwerthbare Methode zur quantitativen Bestim-
mung des Teichplanktons.
Forsch-ber. Biol. Stn. Pl6én, iii, 180-7.
Rev. Z. C., ii, 72.
95a. Ueber die Méglichkeit einer biologischen Bonitirung von
Teichen.
Allg. Fisch. Zeit., xx, 14 pp.; also Jahresb. Schles. Fisch-Ver.
*96. Zielen und Wege der Teichwirthschaft.
Zeit. f. Fischerei, iv, 144.
*96a. Ein Versuch die teichwirtschaftliche Station in Trachenberg
unmittelbar fiir die Praxis nutzbar zu machen.
Zeit. f. Fischerei, iv.

*96b. Die natiirliche Nahrung unserer Teichfische.
Allg. Fisch. Zeit, xxi, 374-7.

WARD, H. B.

94. A Preliminary Report om the Worms (mostly Parasitic) Col-
lected in Lake St. Clair, in the Summer of 18938.
Bull. Mich. Fish. Comm., 4, 49-54, 1 table; also in Stud. Zool. Lab.
Univ. Nebr., No. 4.
Faunistic.

95. The Food Supply of the Fish in the Great Lakes.
Nebr. Lit. Mag., i, 107-24, 2 pl.; also in Stud. Zool. Lab. Univ.
Nebr., No. 11; Bien. Rept. Mich. Fish Comm., xii, 117-29.

96. The Food Supply of the Great Lakes, and Some Experiments
on its Amount and Distribution.

Trans. Amer. Mic. Soc., xvii, 242-54, 2 pl.; also in Stud. Zool.
Lab. Univ. Nebr., No. 12.
Rev. Z. C., iii, 208-5.

962. A New Method for the Quantitative Determination of Plankton
Hauls.
Trans. Amer. Mic. Soc., xvii, 255-60; also in Stud. Zool. Lab.
Dniy. Nebr., No. 18.
Rey. Z. C., iii, 225; Ber. Fisch. Ver. Ost-Preussen.

96b. A Biological Examination of Lake Michigan in the Traverse
Bay Region.
Bull. Mich. Fish. Comm., 6, 1-71, 5 pl.; also in Stud. Zool. Lab.
Univ. Nebr., No. 16.
Rev. Z. C., iv, 176-7; J. R. M. S., 97, 25; ef. Nat. Sci., x, 8-9.

98. Report of the Zoologist. Fish Food in Nebraska Streams.
Ann. Rept. Nebr. Bd. Agr., 97, 272-9; also in Stud. Zool. Lab.
Univ. Nebr., No. 28.

Rev. Z. C., v, 606.
Brief discussion of conditions and list of species found.

Ba a)

296 HENRY B. WARD:

98a. Aquacultural Experiment Stations and their Work.
Proc. Amer. Fish. Soc., xxvii, 125-9.
WARD, R. H.

95. Improved Methods of Collecting Aquatic Micro-Organisms.

Amer. Mo. Mie. Jour., xvi, 33-41. 1 pl.
WARREN, H. E., AND WHIPPLE, G. C.

95. |The Thermophone, a New Instrument for Obtainining the Tem-
perature of a Distant or Inaccessible Place and Some Observa-
tions on the Temperature of Surface Waters.

Amer. Meteorol. Jour., xii, 35-50. 2 pl.
*95a. The Thermophone, A New Instrument for Determining Tem-

peratures.
Tech, Quar,, viii.
WEBER, E.-F.
98. Faune rotatorienne du bassin du Léman (tre partie). °

Rey. Suisse Zool., v, 263-354. 6 pl.
Abst. Am. Nat. xxxiii, 163.
98a. Faune rotatorienne du bassin du Léman (2me partie).
Rey. Suisse Zool., v, 355-785. 10 pl.
WEBER, M.
*97. Beitrige zur Kenntniss der Fauna von Siid-Afrika, I Zur
Kenntniss der Siisswasserfauna von Siidafrika.
Zool. Jahrb., Abt. Syst., x, 135-200. 1 pl. 2 charts.
Rev. Z. C., iv, 825-8; J. R. M. S., 97, 275.
WELTNER, W.
*94._ Forschungsberichte aus der Biologischen Station zu Plén.
Zeit. f. Fischerei, ii, 5. q
*95. Spongillidenstudien, III. Katalog und Verebreitung der bekannt-
en Siisswasserschwimme.
Arch, f. Naturges., 95, i, 114-44.
Rev. Z. C., ii, 521-2.
Taxonomic; data on distribution, regions, ete.
95a. Biologische Siisswasserstationen.
In M. von dem Borne, Kiinstl. Fischzucht, Berlin, 186-96. 16 fig.
*96. Die Cladoceren Ost-Afrikas.
Deutsch Ostafrika, iv.
*96a. Die Coelenteraten und Schwaimme des Siissen Wassers Ost-
afrikas.
Deutsch Ostafrika, iv, 1-8. Rey. Z. C., iv, 401.
WESENBERG-LUND, C.
*94. Gronlands Ferkswandentomostraca, I. Phyllopoda branchio-
poda et Cladocera.
Vid. Med. Nat. Forh. Kjobenhayn. p. 82.
*96. Biologisk Undersogelser over Ferskvandorganismer.
Vid. Meded. Nat. Forh. Kjobenhayn, (5), vii, 105-74.

98. Ueber danische Rotiferen und iiber die Fortpfianzungsverhalt-
nisse der Rotiferen.

Z. A., xxi, 200-11. Rev. J. R. M. S., 98, 309.

A ne
* | ee

RECENT FRESHWATER INVESTIGATIONS 297

WESTERN, G.

94.

Some foreign Rotifers to be included in the British Catalogue.
Jour. Quekett Mic. Club, 2, v, 420-6.
Rev. Z. C., iv, 181-2.
Faunal list with important biological data.

WHIPPLE, G. C.

94.

94a.

94b.

95a.

96.

96a.

*96b.

97.

97a.

97b.

97c.

97d.

Some Observations on the Growth of Diatoms in Surface
Waters.
Tech. Quar., vii, 214.
Rey. J. R. M. S., 95, 345; Amer. Mo. Mic. Jour., xvi, 140-5.

Synura.
Amer. Mo. Mic. Jour., xv, 257-62. 1 pl.
Cf. Ann. Rept. Boston Water Board, xviii.

A Standard unit of size for Micro-Organisms.
Amer. Mo. Mic. Jour., xv, 377-81, 2 fig. 1 pl.
Abst. J. R. M. S., 95, 386.

The Thermophone.
Science, n. s., ii, 639-43.

Some Observations on the Temperature of Surface Waters; and
the Effect of Temperature on the Growth of Micro-Organisms.
Jour. New Eng. W. W. Assn., ix, 202-22. 5 pl.

Experience with the Sedgwick-Rafter Method at the Biological
Laboratory of the Boston Water Works.
Tech. Quar., ix, 275-9.

Some Observations on the Relation of Light to the Growth of
Diatoms. ;
Jour. New Eng. W. W. Assn., xi, 1-26. 5 pl.

Report on the Organisms in the Boston Water Supply.
Ann. Rept. Boston Water Works, xix.

Microscopical Examination of Water, with a Description of a
Simple Form of Apparatus.
Science, n. s., vi, 85-9.

Raphidomonas.
Jour. New Eng. W. W. Assn., xi, 348-56. 1 pl.
Extraordinarily abundant in Lynn water supply on one occasion.

Biological Studies in Massachusetts, No. 1.

Am. Nat., xxxi, 503-8. 2 pl.

Biological Studies in Massachusetts, No. 2. Microscopical or-
ganisms.
Am. Nat.. xxxi, 576-81.

Biological Studies in Massachusetts, No. 8. Geographical dis-
tribution of microscopical organisms.
Am. Nat., xxxi, 101-626.

298 HENRY B. WARD:

88. Classification of Lakes according to Temperature.
Am. Nat,, xxxii, 25-33.
*98a.. Some Observations on the Growth of Organisms in Water
Pipes.
Jour. New Eng. W. W. Assn., xii, 1.
WIERZEJSKI, A.
93. Die Raderthiere Galiziens. (Czeckish; German abstract).
Anz. Akad. Wiss. Krakau, xxvi, 161-265. 3 pl.
*95. | Przeglad fauny skorupiakow galicyjskich-Krakau, 56 pp. 1 pl.
German resumé as Uebersicht der Crustaceen-Fauna Galiziens.
Anz. Akad. Wiss. Krakau, Juni 95, 170-8.
Rey. Z. C., ii, 346-7.
Systematic-faunistic.
WILLE, N. .
96. Resultate einer vorlaufigen Untersuchung tiber Organismen in
Christiania-Trinkwasser. (Mitth. Biol. Ges. Christ., 17 Okt. 95).
B. C., xvi, 125-6.
Wo ccorrt, R. H.
94. The Insecta and Acarina of Lake St. Clair. A Preliminary Re-
port.
Bull. Mich. Fish Comm., 4, 55-6.
Systematic-faunistic.

98. New American Species of the Genus Atax (Fab.) Bruz. |
Zool. Bull., i, 279-85, 6 fig; also Studies Zoo]. Lab. Univ. Nebr.,
No. 23. :

Systematic-faunistic.

WOLTERSTORFF, W.
*96. Die ‘‘Zoologische Station’’ des naturwissenschaftlichen Mus-
eums zu Magdeburg.
Blatter f. Aquar. u. Terr. Freunde, vi, 13-5.

WoopwortsH, W. McM.
96. Preliminary report on Collections of Turbellaria from Lake St.
Clair and Charlevoix, Michigan.
Bull. Mich. Fish Comm., 6, 94-5.
Faunal list with notes.

96a. Report on the Turbellaria collected by the Michigan State Fish
Commission during the Summers of 1893 and 1894.
Bull. Mus. Comp. Zool., xxix, 239-43. 1 pl.

97. On some Turbellaria from Illinois.
Bull. Mus. Comp. Zool., xxxi, 1-16. 1 pl.
Systematic-faunistic study. Valuable bibliography.

Yuna, E.

97. Le Plankton d’eau douce.
La Semaine Littéraire, 97, 519-21.
Popular discussion of methods, investigators and results.

RECENT FRESHWATER INVESTIGATIONS 299

ZACHARIAS, O.

93.

98a.

93b.

94.

94a.

94b.

94e,

94d.

94e,

94f.

94g.

94h.

94i.

94k.

94].

Forschungsberichte aus der biologischen Station zu Plon.

I, Fauna des grossen Pléner Sees. IJ. Beschreibungder neuen
Formen. III. Biologische Mittheilungen.
Theil 1, Berlin, 52 pp. 1 taf.

Die mikroskopische Organismenswelt des Siisswassers in ihrer
Beziehung zur Ernabrung der Fische.
B. C., xiii, 155-60; Jahresb. Centr. Fisch. Ver. Schles.-Holstein.

Fauna des Grossen Pléner Sees.
B. C., xiii, 377-82. (From Forsch-ber. Biol. Stn. Plon, i.)
Merely a list of species.

Forschungsberichte aus der Biologischen Station zu Plon.
Theil 2, Berlin, vii and 155 pp. 2taf. 1 landkarte.
Rev. Z. C., i, 215-8.

Faunistische Mittheilungen.
Forsch-ber. Biol. Stn. Plon, ii, 57-90.

Forschungsergebnisse am Grossen Pléner See.
Z. A., Xvii, 33-5.
Review of two years work at Ploén.

Beobachtungen am Plankton des Grossen Pléner Sees.
Forsch-ber. Biol. Stn. Pl6én, ii, 91-137.

Ueber die Vertheilung der Planktonorganismen innerhalb
eines Sees. (From Forsch-ber. Biol. Stn. Pl6én, ii.)
B. C,, xiv, 122-8; Trans. Rev. Biol. Nord France, vi, 185-94; Boll.
Sci., xvi, 89-92, 113-16; Abstr. J. R. M.S., 94, 552.

Ueber Periodizitat und Vermehrung der Planktonwesen.
B. C., xiv, 226-30.

Aus der biologischen Stisswasser-Station am Gullsee in Minne-
sota.
B. C., xiv, 299-300.
Review of Nachtrieb, 94.

Die biologische Stisswasserstation der Universitat von Illinois.
B. C., xiv, 559-60.
Review of Forbes, 94.

Biologische Untersuchungen in amerikanischen Seen.
B. C., xiv, 603-7.
Short review of the work of Reighard and Ward.
Ueber die wechselnde Quantitét des Planktons im Grossen
Ploner See.
B. C., xiv, 651-6.
Rev. Z. C., i, 786; J. R. M. S., 94, 552.
Das dritte Arbeitsjahr der Biologischen Station zu Plén.
Z. A., xvii, 448.
Statistische Mitteilungen tiber das Plankton des Grossen Pléner
Sees.
Z. A., xvii, 457-61.

300

95.

95a.

95b.

95c.

95d.

95e.

95i.

95k.

*951.

HENRY B. WARD:

Forschungsberichte aus der Biologischen Station zu Plén.
Theil 3. Berlin. 209 pp. 2pl. 3 tab.
Rev. Z. C., ii, 70-3.
Faunistische Mittheilungen.
Forsch-ber. Biol. Stn. Plon, iii, 73-96. 2 taf.
Description of new species and data regarding known forms.
Ueber die wechselnde Quantitat des Plankton im Grossen Ploner
See.
Forsch-ber, Biol. Stn. Plon, iii, 97-117.

Based on weighings made regularly from March to September.
Ueber die horizontale und verticale Verbreitung limnetischer
Organismen. f

Forsch-ber. Biol. Stn. Plon, iii, 118-28.

Fortsetzung der Beobachtungen iiber die Periodicitit der Plank-
tonwesen.
Forsch-ber. Biol. Stn. Plon, iii, 129-44.
Record of daily observations throughout the year.

Statistische Mitteilungen aus der Biologischen Station am
Grossen Pliner See. II-XII.
Z. A., xviii, 28-29, 70-1, 87-9, 125-7, 140-2, 190-3, 256-9, 305-8, 367-71,

414-9, 448-52.

Tables of amount and composition of plankton hauls,

Uber die Ziele und Gesichtspunkte einer wissenschaftlichen
Durchforschung der Siisswasserbecken.
Deutsche Fisch. Zeit., xviii, 89-91. (Beilage.)

Ueber den Unterschied in den Aufgaben wandernder und sta-
bilier Siisswasserstationen.

B. C., xv, 378-84.

Ueber den Friihjahrs-Vegetation limnetischer Bacillariaceen im
Gr. Ploéner See.

B. C., xv, 517-9.

Ueber die vertikale Verteilung limnetischer Crustaceen, insbe-
sondere iiber diejenige von Cyclops oithonoides.
B. C., xv, 686-8.

Rey. Z. C., iii, 324-5; J. R. M. S., 95, 6381.

Ueber die Mégiichkeit einer biologischen Bonitierung von Fisch-
teichen.

B. C., xv, 847-8.

Ueber das Gewicht und die Anzahl mikroskoyischer Lebewesen
in Binnenseen.

Helios, xiii, 103-5, 113-9. Also in Gaea, 1896, 1, 31-6.

Planktonmessungen im Grossen Ploner See.

Corr. Bl. f. Fischzucht, iii, 7-8.

Sucherokular mit Irisblende.

B. C., xvi, 30-1; also Forsch-ber. Biol. Stn. Plén, iv, 288-90.

*96b.

96ce.

*96d.

96e.

96f.

96g.

96h.

97.

97a.

98c.

. 98d.

RECENT FRESHWATER INVESTIGATIONS 301

Ueber Periodicitéat und Vermehrung der Planktonwesen.
Zeit. f. Fischerei, ii, 149-53.

Ueber der natiirliche Nahrung der jungen Wildfische in Bin-
nenseen.

B. C., xvi, 60-6.

Orientirungsblatter ftir Teichwirthe und Fischziichter.

1. Die naturliche Nahrung der jungen Wildfische in Binnenseen.
2. Verschiedene Mittheilung tiber das Plankton unserer Seen
und Teiche.

Pl6n, 8°, 12 pp, and 16 pp.

Forschungsberichte aus der Biologischen Station zu Ploén.
Theil 4. Berlin. 290 pp. ltaf. 45 fig. 1 karte.

Quantitative Unterschungen tiber das Limnoplankton nebst An-
leitung zur Vornahme von Zahlungen und Volumenmessu ngen.
Berlin. 64 pp. From Forsch-ber. Biol. Stn. Plon, iv, 1-64.

Rev. Z.C., iii, 445-7.

Ergebnisse einer biologischen Excursion an die Hochseen des
Riesengebirges.

Forsch-ber. Biol. Stn. Plon, iv, 65-87.
Monatsmittel der Plankton-Volumina.
B. C., xvi, 803-6.

Abst. Z. C., iv, 52.

Forschungsberichte aus der Biologischen Station zu Plon.
Theil 5. Stuttgart. 180 pp. 4 taf. 1 tab.

Neue Beitrage zur Kenntniss des Stisswasserplanktons.
Forsch-ber. Biol. Stn. Plon, v, 1-9. 1 taf.

Description of new limnetic species.

Biologische Beobachtungen an den Versuchsteichen des
Schlesischen Fischereivereins zu Trachenberg.

Forsch-ber. Biol. Stn. Plon, v, 10-28.

Zur Mikrofauna der Sandforter Teiche.
Forsch-ber. Biol. Stn. Plén, v, 112-4. 1 text fig.

List of forms from fish ponds; cf. Lemmermann, 97.

Leipziger Plankton.

Zeit. f. angew. Mikr., ili, 141-6.
Das Heleoplankton.
Z. A., Xxi, 24-32; Rev. Z. C., v, 160-1

Das Potamoplankton.

Z. A., xxi, 41-8; Rey. Z. C.,v, 161.

Forschungsberichte aus der Biologischen Station zu Plon.
Theil 6. Abt.1, Stuttgart. 87 pp. 3 pl.

Rey. B. C., xviii, 299-301.

Summarischer Bericht tiber die Ergebnisse meiner Riesenge-
birgsexcursion von 1896.

Forsch-ber. Biol. Stn. Plon, vi, 1-8; Rev. Z. C., v, 353.

Forschungsberichte aus der Biologischem Station za Plén.
Theil 6. Abt. 2, 87-219. 2taf. 1 karte.

Rey. B. C., xviii, 718-20.

302 HENRY B. WARD:

98e. Untersuchungen iiber das Plankton der Teichgewasser.
Forsch-ber. Biol. Stn. Plon, vi, 89-139. 1 taf.
Rev. Z. C., v, 488-9.
98f. Ueber einige interessante Funde im Plankton séachsischer
Fischteiche.
B. C., xviii, 714-8.
98g. Ueber die mikroskopische Fauna und Flora eines im Freien
stehenden Taufbeckens.
Z. A., xxi, 670-3.
ZACHARIAS AND LEMMERMANN.
96. Ergebnisse einer biologischen Excursion an die Hochseen und
Moorgewasser des Riesengebirges.
Berlin. 80 pp. 26 fig. 1 pl. (From Forsch-ber. Biol. Stn. Pl6n, iv).
Rev. Z. C., iii, 425-6. ;
ZEPPELIN, E. VON.
95. Les observations du Dr. Hofer sur le Plancton dans le lae de
Constance.
Arch. sci. phys. et nat. Genéve, 3, xxxiv, 458-60.
Rey. Z. C., iii, 315.
ZIMMER, C,
98. Ueber tierisches Potamoplankton.
B. C., xviii, 522-4; Rev. Z. C., v, 605; J. R. M. S., 98, 528.
ZOGRAF, N,
95. An Attempt to Explain the Origin of the Fauna of Lakes in
European Russia. (Russian).
Bull. Ac. Imp. St. Pet., iii, 2. 19 pp. 1 map.
96. Essai d'explication de ]’origine de la faune des lacs de la Russie
da’ Europe, (Communication preliminaire).
C. R. ILI. Cong. Int. Zool. Leyde, 183-95. Rev. Z. C., ili. 581-3.
97. What the Hydrobiologic Station on Lake Glubokoe (Deep Lake)
Has Done and Ought todo. (Russian).
Arb. Ichth. Sect. K. Russ. Acclim. Ges., ii, 202-6. 1 pl.
Rev. Z. C.. iv, 430-2.
ZSCHOKKE, F.
94. Die Tierwelt der Juraseen,
Rev. Suisse Zool., ii, 349-76. 1 Taf.
Rey. Z. C., i, 737-8 (= Zschokke, 94a); J. R. M. S., 95, 42.
94a. Neuere Arbeiten iiber die Tierwelt des siissen Wassers.
Z. C., i, 733-8.
95. Die Fauna hochgelegener Gebirgseen (with appendix by
Stingelin).
Verh. Naturf. Ges. Base], xi, 36-133. 1 pl.
Rey. Z. C., ii, 99-102: B. C., xv, 506-17 (= Imhof, 95, q. v.).
5a. Die biologische Station zu Plon nach den Forschungsberichten.
Teil 2u.3. B.C., xv, 408-15.
97. Fauna Helvetica. Seenfauna.
Bibl. schweiz. Landeskunde, iv, 6, 24 pp. Rev. Z. C., v, 353-4.
Including references to all forms except insects, from 1680-1897.

RECENT FRESHWATER INVESTIGATIONS 3038

SUMMARY OF PROGRESS.

Among the general works treating of freshwater subjects
the limnologic monograph of Forel easily deserves the foremost
place, both by virtue of the breadth of its scope and by reason
of the completeness and precision of its treatment. Planned to
cover the entire field for a single lake, Geneva in Switzerland,
the work is worthy of the magnificent sheet of water with
which it deals. It is truly monographic and an indispensable
aid to every limnologic enterprise. Thus far but two volumnes
have appeared, the first of which (Forel, 92) falls really just
without the time limits of this review, yet for completeness
callsfor mention here. It first deals with the apparatus employed
and the plan of the entire work, and then covers the sections
on I Geography, II Hydrography, depth, shore, bottom, III
Geology, IV Climatology, V Hydrology, sources, outflow,
level. The second volume (Forel, 95) handles sections VI
Hydraulics, current, movements, sevches, waves, VII Thermics,
VIII Optics, transparancy, color, mirages, 1X Acoustics, X
Chemics, density, odor and value as drinking water.

The American student possesses in Russell (95) a valuable
discussion of the geologic and physiographic features of North
American lakes and lake systems. Lampert (98) has given a
semi-popular yet thorough and accurate presentation of life in
fresh-water. The larger part of the work is devoted to a sys-
tematic and biologic description of the genera which occur in
the German waters, but there are also important chapters on
the history of freshwater investigation and on general limno-
logic questions. Apstein has published (96) a convenient and
valuable work on the freshwater plankton which presents the ex-
tensive investigations of the author on Holstein lakes in compar-
ison with theresults achieved by other workers elsewhere. The
details of the work are referred to under special topics later in
this article. Klunziger (97) has given an admirable review of
the methods and results of plankton work, with special refer-
ence to the problems of fish culture, and Field (98a) has pre-
sented a concise study of the same question.

3804 HENRY B. WARD:

But few bibilographies bearing upon the subject of fresh-
water investigations have yet been published. That of Dolley
(96) is most largely marine, while those of Apstein (96) and
Field (98a) are exclusively confined to plankton studies. Others
treating of single genera or groups occur in systematic papers
on these forms.

The work of Mez (98) is rather of a technical character for
use in water analysis and treats of Protozoa alone among ani-
mal forms, discussing particularly their relation to the quality
of the water and their dependence upon its physical and chem-
ical character. American students are awaiting eagerly a
somewhat similar work by Whipple, which is already an-
nounced.

Stokes (96) is a convenient summary, largely taxonomic, of
freshwater genera; it contains, however, data on apparatus for
collecting and notes of a biological character.

In the line of apparatus for special work on limnetic ques-
tions much has been done and yet mostly in the direction of
adapting that used in marine investigations to the conditions
in fresh water. A recent and comprehensive discussion of the
former may be found in Hensen (95), whose assistant, Apstein,
was the first to apply the same methods to freshwater studies;
the latter has given (96) an extended account of the forms of
apparatus used in his plankton investigations and somewhat
generally applied by others also. Forel (92, 95) mentions
numerous pieces of apparatus used in physical, chemical and
metereological studies on Lake Geneva. Here also Ule (94).
Fric and Vivra’s account (94) includes figures of many kinds
of smaller collecting appliances, and Klunziger (97) refers in a
general way to plankton apparatus. R. H. Ward (95) speaks
of the advantages of the Birge net, particularly in shore col-
lecting and among marsh plants.

Of new physical apparatus, the thermophone invented by
Warren and Whipple (95, 95a; ef. also Whipple, 95) is un-
doubtedly the best instrument yet devised for recording water '
temperatures. See Linsbauer (95) for a method of determining
the amount of light at a given depth.

RECENT FRESHWATER INVESTIGATIONS 305

The vertical net, planned by Hensen and first used by
Apstein in fresh water, is described by the latter (96). Some
improvoments in detail were made by Reighard (94a) and by
Kofoid (97) while the latter adapts the vertical net by an in-
genious arrangement to oblique hauls in shallow water. In a
later paper (98a) he gives a careful account of the best method
for the construction of the vertical net. Vertical closable nets
worked by sliding weights are described by Birge (97a) and
Marsh (97), and a horizontal net which can be opened and
closed by a cord by Lakowitz (96). The former are prompt
and accurate in action and may be used at any depth, having
been tested up to 130 m., while the latter is apparently cum-
bersome, if not uncertain in action, and on the authority of the
author can be made use of only up to 20 m. in depth. As to
the material, fine silk gauze, of which such nets are constructed,
Frenzel (97a) makes some criticisms regarding its inconstancy;
since while a single haul does not usually close the pores to a
noticeable extent there are exceptions, and furthermore con-
tinued use is sure to modify its filtering capacity, thereby falsi-
fying all calculations. The pores are closed by accumulated
detritus, not by diatoms or other small planktonts. The net
should be vigorously washed and wrung out each time to clean
out the pores. Hensen (97) questions these statements regarding
clogging and objects to such drastic treatment in cleaning the
net. Recently Kofoid (97a) has attacked the accuracy of
results obtained by the vertical net on the opposite basis: that
it allows the escape of too many organisms since ‘‘the silk
retains from 5 per cent. to less than 0.1 per cent of the total
number of organisms present excluding bacteria, as contrasted
with the catch of the Berkefeld filter;’’ volumetrically the catch
equals from one-half to only one forty-fifth of the amount
actually present in the water. Reighard (98) calls attention to
the fact that the larger size of the nets used by some observers
makes clogging a less important factor than in studying silt-
laden waters with a small net. Shrinkage being largely if not
entirely eliminated by previous treatment of the net, leakage is

20

306 HENRY B. WARD: '

the only uncertain factor, and since the organisms which escape .
thus are the smallest, their volumetric importance may be
slight; but they must be investigated numerically by other
methods as the numerical estimations made from catches of
the vertical net are evidently most open to question.

As the vertical net does not collect all the material in the »
column of water through which it passes, various means have
been adopted to ascertain the portion of water actually strained
or the coefficient of the net. Hensen’s earlier, extremely com-
plicated method was pointed out by Reighard (94a) and Ward
(96b) to be open to question, and the former proposed an experi-
mental method (94b) for precise determination of the efficiency of
the net. Hensen (95) advocates the use of a tin plate covering the
mouth of the net except a small opening in the center. By
counting the number of individuals of a well marked species
caught under these conditions and comparing with the number
caught by the full opening of the net, its coefficient may easily
be obtained. The method, however, evidently affords more
opportunity for error than that proposed by Birge (97a) who fil-
tered the entire column of water in a tin cylinder having the di-
ameter of the net opening in order to ascertain the coefficient of
the net. This was found to be about two, and the difference
between maximum and minimum hauls of the net was no
greater than that shown by the column of water in the cylinder
at sucessive tests.

For Crustacea alone Birge found that the clogging of the net
in an 18 m. haul did not markedly affect its coefficient over
that employed for the 3 m. haul until after the rapid increase
of the phytoplankton in July. For the short haul the clogging —
made at no time any visible alteration in the coefficient which
in the opinion of Birge is furthermore one of the most constant
factors, and quite as accurately determined as any other. How-
ever, Frenzel (97a) is inclined to think the coefficient decidedly
variable. Kofoid (97a) ascertained the coefficient of the net
in use at the [linois station, according to the original method
of Hensen, to be 1.32; experimentally it was shown to vary

RECENT FRESHWATER INVESTIGATIONS 307

from 1.5 to 5.7, where the greatest variation is largely due to
the clogging of the net by heavy plankton hauls. Reighard
(98) proposed to eliminate all of the difficulties connected with
clogging, shrinkage and net coefficient at once by measuring
the volume of water that actually passes through the net in
each haul. To this end a small current meter is to be placed
in the mouth of the net and the volume calculated from the
rate of the current passing through the opening. Experiments
in this direction are now in progress.

As a substitute for the vertical net in obtaining the plankton
from a certain quantity of water, several investigators experi-
mented almost simultaneously with a plankton pump, so con-
structed that a definite amount of water is delivered by a single
stroke, the depth from which it comes being regulated by the
position of the mouth of the attached hose. The greatest diffi-
culty which presents itself is the proper filtration of the water
discharged from the pump. The advantages urged in its favor
are (Kofoid, 97) greater accuracy in determining the volume
strained, the wide applicability of the method in shallow water,
in currents, under ice, amid vegetation, for water very rich or
very poor in plankton, and the rapidity of the process. The
pump used by Kofoid was very large. Frenzel (97) who
advances much the same arguments in favor of this apparatus,
which he used with particular success in obtaining plankton
under the ice, gives no particulars regarding his pump. For-
dyce (98) describes a pump which is easily portable and can be
used with advantage in small bodies of water.

A centrifugal apparatus has been used with success by Juday
and Kofoid (97) on preserved material in the measurement of
plankton volumes. Dolley (96) has employed a larger form,
called by him the planktonokrit, in the precipitation and
measurement of living plankton. This machine has been
used by Field (98) who later (98a) maintains its great superior-
ity for volumetric estimation over all other methods yet dis-
covered. Jackson (96, 98) found, however, that while good
results were obtained with Infusoria and Rotatoria, the reverse

308 HENRY B. WARD:

was true if Cyanophyceae were present, as these are not
thoroughly precipitated owing to low specific gravity. The
material is also matted together, preventing equal distribution
on the slide if numerical estimation is to be employed. Kofoid
(97a) emphasizes the selective error of the centrifuge on living
plankton.

In microscopical water analysis for technical purposes the
Sedgwick-Rafter method almost universally employed has been
subject to modification in detail by Jackson (96, 98), while
Whipple (96) has analyzed most clearly the various errors of
the method and the value of each. The same author has also
(97) planned a simple form of apparatus for water analysis.
Leeds gives a valuable discussion and’ summary of these
methods.

In the filtration of plankton organisms Kofoid (97a) found
that the sand filter retained only 40 to 65 per cent of the num-
ber of organisms present and advocated as more satisfactory and
precise the Berkefeld filter. Reighard (98) objects to the con-
tamination of the plankton resulting from the use of the latter,
and Jackson (98) considers that the slow rate of filtration
makes its use entirely unpractical.

For the manipulations connected with the enumeration of
individuals in plankton hauls various minor pieces of apparatus
have been suggested; only the more important need be noticed
here. Whipple (94b) advised the employment of an ocular with
a field suitably ruled, and Zacharias (96a) introduced an ocular
of large field with an iris diaphragm. As the enumeration of
organisms recorded without reference to size and character is
extremely misleading, Whipple (94b) proposed a standard unit
of size, 20x20 microns, as a means of correcting the error.
Tables for common organisms and an ocular with ruled field
assist in the computation. Comparison of lines platted to show
the numerical and areal values of the organisms in a haul with
the albuminoid ammonia curve forthe same demonstrate the
much closer correspondence of the areal estimation with the
amount of organic substance present. By the use of logarith-

RECENT FRESHWATER INVESTIGATIONS 309

mically ruled paper Scourfield (97a) was able to represent
extreme ranges in number of organisms while at the same time
proportionate changes in number are indicated by lines having
the same angle of slope in whatever part of the chart they may
be situated.

The freshwater stations of the world have not all been
founded within the last five years. Yet only the Swiss and
Bohemian stations can be said really to antedate this, and even
then much of their important work comes within this period.
As to what constitutes a ‘‘station’? and what each has accom-
plished I have spoken in another place,* and shall refer here
only briefly to such articles concerning the origin, manage-
ment and functions of those formal enterprises as would not
easily be included under other headings. A general account of
such institutions is given by Lampert (98), and for America by
Kofoid (98b). Scourfield’s appeal (96, 97) for the foundation
of a British station, and Fric’s presentation (97 ) of Europe’s
example contrast well the position of the two countries in this
movement.

The oldest definite station in Europe, the Bohemian, is
described in Frie and Vavra (94, 97). The Plon station and
its opportunities are set forth in Klunziger (96), Zacharias
(93, 94, et alia), Zschokke (95a). Other German stations are
noted by Woltersdorff (96), Frenzel (95). In Hungary, Entz
(97), and in Russia Zograf (97) record similar enterprises. In
Italy Garbini’s long and successful investigations on Lake
Garda entitle that station to a high rank. In North America
work on the Great Lakes is recorded by Reighard (93), on
Lake Mendota by Birge (95, 97), on Gull Lake, Minn., by
McMillan (93), Nachtrieb (94), Zacharias (94b), and on Turkey
Lake by Eigenmann (95). The work of the Illinois station at Ha-
vana, the most extensive American enterprise of this character
thus far, is fully set forth in the reports of the director (Forbes,
94, 97) which are inspiring appeals to limnobiologic investiga-
tion. Other references to this station are Kofoid (96a), Ross (97b)

* Science, n. 8., ix, 497-508.

310 HENRY B. WARD:

Zacharias (94g). The technical station of the Boston water

works is well described by Whipple (97b) who sets forth clearly
the importance of such an enterprise in its relation to the
water supply of a great city.

Last year the United States Fish Commission made a pre-
liminary survey of the region about Put-in-Bay, Lake Erie,
with reference to the fitness of this point for an experiment
station in connection with the government fish hatchery. The
work will be continued the coming summer (H. M. Smith, 98.)
The necessity for an aquacultural experiment station, the
right of such a foundation to governmental support, its proper
location and function and allied questions are discussed by
Ward (98a). Zacharias (95g) believes that a wandering lacus-
trine station is of secondary importance; some evidence to the
contrary could be found in the work of Fric and Vavra (94,
97), Reighard (94), Ward (96b).

The temperature conditions of freshwater lakes were dis-

cussed by Fitz Gerald (95). In temperate climates, deep lakes

show a winter curve running from O° C at the surface to 4° C
at the bottom, while the summer curve is reversed, extending
from 24° C at the top to 7°-10° C at the bottom. Whipple
(95a) shows that a temperature difference of 3° C prevents wind
from maintaining circulation and the lower region remains
stagnant until the fall overturning mixes the water of the lake.

Birge (97a) made a most careful study of the temperature con- —

ditions and variations in Lake Mendota. The warming of the
water in the spring is gradual and uniform until the difference
between top and bottom is7°—8°C. Then gentle winds with high
temperature lead to the formation of a mass of warm water

on the surface so thick that however the wind may blow there is

always a warm stratum floating on the colder water. Immediately
below the warm water is a layer a meter or less in thickness in
which the temperature falls very rapidly; this layer Birge
names the thermocline. Below it the temperature falls gradu-
ally to the bottom of the lake. Once formed, late in June, at
about eight meters of depth, it moves downward slowly and

RECENT FRESHWATER INVESTIGATIONS 311

irregularly, depending upon the action of the wind, and
reaching the bottom asa result of the late September gales,
disappears. These conditions are of extreme biological im-
portance since below the thermocline the water is stagnant
during the entire summer and becomes unfit to support most
forms of animal life. The sub-thermoclinal water is reported
by Whipple (95a) and others to be malodorous, deficient in
oxygen and rich in the products of decay. Its overturning is
the occasion of a rapid increase in the diatoms of the plankton.

Whipple (98) distinguishes three types of lakes, polar, tem-
perate and tropical, according to the surface temperature,
which in lakes of the first type is never above that of max-
imum density (4° C), in those of the tropical type never below
that point, and in lakes of the temperate type sometimes above
and sometimes below it. He also designates three orders of
lakes on the basis of the bottom temperature, which in those of
the first order is practically constant at or near the point of
maximum density; in those of the second order the bottom
temperature fluctuates but never very far from the same point
while in lakes of the third order the bottom temperature rarely
varies from that of tho surface. With regards to periods of
circulation which are so important for the development and
distribution of the plankton, he says: ‘‘ Speaking in very gen-
eral terms, we may sy that lakes of the first order have no
circulation; lakes of the third order no stagnation (except in
winter); and lakes of the second order have both circulation
and stagnation.” According to Birge (98) the thickness of the
surface stratum of warm water depends on the wind, the ex-
posure of the lake, and among those similarly located in these
particulars, upon the area of the lake, being less in a lake of
smaller area. The bottom temperature of a small lake is likely
to be lower than one would expect from the depth merely and
that of a large lake higher. Here also Ule (93), Langenbeck
(93) and Dolan.

The amount of oxygen present in various parts of a water
basin and the dissemination of gases through the water is of

312 HENRY B. WARD:

the greatest importance inits bearing on conditions of existence
in a lake. Drown (93) found that in water basins in winter
under the ice there is a deficiency in the amount of oxygen
present, which increases from the surface downward. Insome
reservoirs the bottom water becomes even malodorous and as
poor in quality as during the summer stagnation period. This
was true only of lakes rich in organic material. The careful
and extended investigations of Hoppe-Seyler (96) on Lake
Constance, Switzerland, show a deficit of oxygen in deeper
waters above the calculated amount. The amount present,
however, is still sufficient to satisfy the respiratory needs of
the abyssal animals, even the most sensitive fish, such as trout.
Knauthe (98) maintains that in somewhat turbid waters the
micro-organisms demand more oxygen than fish and larger
forms and in stagnant waters far more than is contributed by
the atmosphere. In daylight the microscopic green plants
give off oxygen to the water so abundantly that in strong sun-
light the maximum is reached in a few hours. Even moon-
light causes an appreciable increase in the quantity of oxoygen;
but in darkness the amount sinks in five or six hours of sum-
mer temperature to the minimum necessary for the Cyprinidae.

Calkins (93) groups the odors of freshwater into three
classes (1) those of chemical or putrefactive decomposition, (2)
those of growth, i. e., excretory products, and (3) those of
physical disintegration. All evidence points to oil globules as
the specific cause of those odors grouped under the last two classes.
Certain odors are associated with definite organisms. Jackson
and Ellms (97) were able to add to the evidence concerning
natural odors and the organisms producing them and to dis-
tinguish sharply between the natural odor and that produced
by the decomposition of the same organism. Here also
Whipple (94a).

The geological and physical features of individual lakes have
been studied by Ule (94a) at Plén, Pero (95) in Italy, Large
(97) in Indiana, Wagner (97) in Bohemia, and Lorenz von
Liburnau (98).

Among the articles noted on the phytoplankton Schroter (97)

RECENT FRESHWATER INVESTIGATIONS 313

presents the most general survey of plant life in the water.
He distinguishes by the vegetation three general types of water
basins, swamp, pond and lake; the swamp plants rise with
vegetative organs above and free from the surface of the water.
In the pond true submerged plants are wanting and only sub-
mersed plants with swimming leaves and submersed plants
with emersed leaves are normally present. To the single
plankton organism the term planktont is applied and among
the lake plants the author differentiates (1) the floating flora, or
phytoplankton with the eulimnetic species of the open water,
the bathy-limnetic forms, half floating, half inhabitants of the
‘littoral zone, and the tycho-limnetic plants, stray elements of
shore or bottom flora; (2) the swimming flora, pleuston, driven
about on the surface and with organs fitted to an aerial exist-
ence; (3), the bottom flora or phyto-benthos, bound to the sub-
stratum and consisting of flowering plants, Characeae, sessile
algae and mosses, epiphytic and endophytic algae, and fungi
and bacteria. Each individual body of water has its own char-
acteristic flora as is shown by comparison of a series of lakes.
A careful study of the plankton shows numerous adaptations
to the conditions of its existence.

These general principles are repeated and emphasized by
examples in the general part of Schroter and Kirchner (96)
which deals with the flora of Lake Constance based upon about
five years of study. The special discussion of the algal flora
of the lake by the second author includes an account of charac-
teristic features and of the composition of each part of the
flora. There were found in the lake the very large number of
361 separate species. No quantitative investigations were
made on the plankton. Here also Bruyant (94) and Magnin
(95).

Among the Cyanophyceae Strodtmann (95, 95a) and Klebahn
(96, 97) find in the so-called ‘‘red bodies ’’ the cause of float-
ing. So long as these are present in sufficient numbers the
algae swim at the surface, when they are scanty or wanting
the algae sink slowly or rapidly to the bottom. The ‘red

314 HENRY B. WARD:

bodies ”’ are actually gas vacuoles in the protoplasm, present in
all the plankton Cyanophyceae, but entirely wanting in the
fixed forms.

On the diatoms of the plankton Zacharias (95h) gives statis-
tical records from the enumeration of plankton hauis during
the year showing the number found at different seasons and
the maxima and minima of various species. Whipple (94)
notes the effect of the fall overturning of the water in producing
a maximum of diatom development by the distribution of an
abundant food supply from the stagnant substratum of the
water. In a later paper (96a) are recorded more detailed obser-
vations on the effect produced by other causes. The maximum
of diatom growth is shown experimentally to be just below the
surface of the lake, to be greater in light-colored water and to
vary in close correspondence to the variation in the intensity of
the light. Apparently the diatoms possess no power to move
upward toward the light but are carried upward by convection
currents in the water. Such conditions prevail particularly in
the fall circulation period. Pero has studied very carefully:
the distribution of the diatoms in the lakes of a single canton
in the Alps.

The ‘‘ water bloom” has been studied by Klebahn (96) who
finds that thirteen different species may give rise to the phe-
nomenon. According to Strodtmann (98) it is only indirectly
the cause of actual damage, varying in amount under different
conditions, and is of direct value as food, particularly to the
Cladocera and Copepoda which are so important as fish food.
Here also Richter (94) and Thomas (97). Seligo (97) dis-
cusses the damage done by the introduced Hlodea canadensis
and believes it probably overdrawn. After considering its re-
lation to the general biology of the water, the author empha-
sizes the small value of the shore plants in the food relations
of freshwater and yet on the other hand the known greater
abundance of fish where such plants are found.

For Ploén and other lakes in Holstein, Klebahn (95) describes
the aquatic vegetation, the regions into which it may be di- a

RECENT FRESHWATER INVESTIGATIONS 315

vided and the forms in each. Here also Lemmermann (95,
96a). Lemmermnan (96), Miiller (98) and Schréder (98) report
on the flora of the lakes in the Riesengebirge, and the latter
undertakes to distinguish the formations of the freshwater
algae, as limnophilous, potamophilous, sphagnophilous creno-
philous, geophilous, lithophilous and kryophilous, giving
faunal data regarding each. Concerning other local floras
there is noted the report of Pieters (94) on that of Lake St.
Clair, Thompson (96) on Lake Michigan and Whipple, Jelliffe
and others on the flora of city water supplies in this country.
On the flora of ponds used for fish culture Lemmermann (97)
and Schroder (97) have made some investigations. The
former reaches certain preliminary conclusions as to the eco-
nomic worth in such ponds of different forms of vegetation.

The freshwater fauna may be considered from two main
standpoints which indicate thus principal subdivisions of the
subject. One may investigate the forms of which it is consti-
tuted or the location in which these forms are found, discussing
accordingly first their composition and second their distribution.

Regarding the composition of the freshwater fauna it may
be said that nearly every paper listed in the bibliography con-
tributes some notes of importance. Under this heading, how-
ever, it is the intention to bring together briefly only those
which for one reason or another lay particular emphasis on
this feature, dealing with taxonomic groups of various size in
their faunal relations. As noted previously the bibliography
makes no claim to completeness on extra-plankton topics. Its
shortcomings are undoubtedly most noticeable under the present
heading. Greater attention has naturally been devoted to con-
tributions treating of North American forms while literature on
freshwater vertebrates has been entirely omitted, and that on
insects almost wholly.

On Protozoa Blochmann presents a very satisfactory general
summary. Schewiakoff (93a) isthe most important contribution
on the group within the limits of this review. In Europe Le-
vander (94a), Entz (96), Francé (97), deal with the protozoan

316 HENRY B. WARD:

fauna of a single region; similarly F. Smith, Kofoid (96) J. C.
Smith and Hempel in this country. Here also Garbini (94a),
Butschinsky. Among papers dealing with one or more subdi-
visions of the group may be noted Schaudinn, Frenzel (97b),
Schewiakoff (93), Seligo (93), Svec and Franeé (97a). On the
Porifera Weltner (95), Hanitsch and Vangel (97).

Fuhrmann (94),‘ Borelli, Szigethy, Vejdovsky, Volz and
Woodworth have contributed to a knowledge of the Turbel-
laria, while Bohmig and Montgomery deal with the Nemer-
tines. The results of Daday’s work (97a), on Balaton Nema-
todes make one wonder whether these free living forms have
not been much neglected heretofore.

On the Rotatoria, a most important plankton group, there
has appeared the recent valuable memoir of Weber. Wierzejski
(93), Levander (94b) and Daday (97b) have contributed to a
knowledge of the group in Europe, and Kellicott, Jennings and
Hempel in the United States. Here also Eckstein, Garbini
(95a), Kertész and Hood. Imhof (95a) and Walker treat of the
Mollusca in connection with freshwater investigations. Call dis-
cusses the relation of the molluscan fauna to different hydro-
graphic basins in a region belonging to several drainage areas.

The splendid monograph of Piersig and the papers of
Koenike, Daday (97d) and Wolcott (98), together with briefer
articles by Soar and Nordenskidld comprise the studies on
Hydrachnids listed. On the entomology of a freshwater body
the work of Hart easily takes the first place; articles by Klap-
alek, Wolcott (94), and Garbini (95d) are also noted.

Among the articles on the Crustacea, those of Garbini (95c)
and Wierzejski (95) are general in their scope. The Entomos-
traca have been studied by a host of investigators, among whom
may be noted Daday, de Guerne, Herrick, Mrizek, Poppe,
Richard, Rizzardi, Sars, Scott, Scourfield, Steuer, Turner,
Viavra and Wesenberg-Lund. On the Ostracoda particularly
are noted the works of Brady and Norman, Vavra, and in this
country Turner and Sharpe.

The magnificent monograph of Schmeil on the Copepoda

RECENT FRESHWATER INVESTIGATIONS 317

deserves prominent notice. Valuable articles on the group
are Mrazek, Marsh (95), E. B. Forbes, Schacht and Brewer
On the Cladocera the revision of Richard (94, 96) is a model
of completeness and accuracy. Birge (93, 94), Ross (96),
Turner (93) in this country, and Stenroos (95, 97), Stingelin
(95), Weltner (96) in Europe, have contributed to a study of
the same group. On ail of the plankton crustaceans much
emphasis has been laid and in most of the articles noted
under the head of distribution may be found important tax-
onomic notes on these groups.

The distribution of freshwater life may be regarded from
the standpoint of the single body of water or through a com-
parative view of different bodies of water. In the latter case
one may consider those bodies which are within a given geo-
graphic area, or those which are associated in character. Ac-
cordingly it is permissible to speak of the geographic, the hydro-
graphic and the areal distribution of freshwater organisms. In
considering first the geographic distribution of freshwater ani-
mals, regions are designated by ordinary geographic terms since
a basis for subdivisions into faunal regions has not yet been
worked out save in Russia by Zograf. Of general value on
the geographic distribution of freshwater animals is the work
of Schewiakoff (93a) on the Protozoa which seems to indicate a
cosmopolitan distribution for these forms. Frenzel (97b)
doubts this on the basis of studies in South America, since of
88 species found in Argentina, 44 are new. . The accuracy of
these studies has, however, been questioned.

Observations on Australian forms are reported by Chilton
and Sars, from the Pacific Islands (Samoa) by Kramer, from
Sumatra by Richard (94c) and from Ceylon by Poppe (95b) and
Daday (98). From eastern Asia Richard (94b) is the only
record of the freshwater fauna noted. From Asia Minor
Barrois (94) and Richard (95, 96c) complete the list.

Northern Africa is touched upon in Barrois (93) and Rich-
ard (93). German East Africa has a well planned biological
survey of governmental character in progress. Reports touch-

318 HENRY B. WARD:

ing upon this topic are Mrazek (95), Weltner (96) and Vavra
(97). Poppe and Mrazek (95) treat of nearly the same terri-
tory and Weber (97) deals with African faunal regions based
on a study of the fishes, decapod crustaceans and mollusks.
The work of Moore in Central Africa is considered under the
fauna relicta. Concerning island faunas Barrois (96) and
Richard (96b) report from the Azores and Richard (98) from —
tbe Canaries. The species are mostly cosmopolitan or known
from adjacent portions of Africa and Europe.

Single brief reports characterize also our knowledge of the
South American freshwater fauna, from the west Borelli,; from
the east Dahl, Ihering, Frenzel (97b) and Richard (97b), and
from the south Vivra (98), with a single note on South Georgia
from Poppe and Mrazek (95a).

In Europe extreme northern points are noted in Richard
(98a), Scourfield (97b) and Wesenberg-Lund (94), Lauterborn
(94a) on the fauna of Helgoland, Scott and Duthie on that of
the Shetland Islands, Scott on Scotland, Western, Scourfield
and§Soar on England and Wales, and Hanitsch and Hood on
Ireland, record the advance in knowledge from these regions.
From Norway, Wille and Huitfeldt-Kaas, and from Finland,
Levander, Nordenskiéld and Stenroos are noted.

From Germany, Schmeil, Piersig, Lampert (98) and Apstein
(96) are of general import; more limited in area is the work of
Zacharias, Apstein (93) and others from Holstein; Hartwig,
Frenzel and others from Central Germany; Lauterborn from
the Rhine; Lameere from Belgium; Klapalek, Svec, and Frie
and Vavra from Bohemia; Jaworowski and Wierzejski (93,
95) from Galicia; Daday, Entz, Francé, Vangel, and others
from Hungary; Schmeil (93a, 94), Lorenzi, Steuer and Richard
(96a) from the eastern Alps, and Vavra (93) and Richard (97)
from Bulgaria and Albania. The Russian articles, probably
exceedingly incompletely recorded, are Zograf (96) and Butsch-
insky (96).

No region has been more carefully studied than Switzerland
and the Alps. The work of Imhof (95a) and especially of

RECENT FRESHWATER INVESTIGATIONS 319

Zschokke (95) and of his students and associates Stingelin,
Fuhrmann and others, is of great value. On the northern
slope of the mountains Hofer, Heuscher and Steck, toward
the west and south and in the Jura Forel, Blanc, Pitard,
Studer, Weber, de Guerne et Richard, Blanchard et Richard
and Pugnat. On the south of the Alpine chain, Garbini, Pero,
Fuhrmann (95), Klunzinger (97a), Wagner (97a); in Italy, Riz-
zardi and Garbini, and in Portugal, Nobre and de Guerne et
Richard (96) are among those noted in the list.

On this continent the work of E. B. Forbes, Herrick and
Turner, Schacht, Sharpe, Turner (94) and Wolcott (98) is
general in extent. On the freshwater fauna of Canada are
noted Koenike and Ross (97); on that of the Atlantic coast
region Montgomery, Calkins, Whipple, and others; on that of
the Great Lakes and contiguous territory, Birge, Jennings, -
Kellicott, Kofoid (96), Marsh, Reighard, F. Smith, Walker,
Ward (94, 96a), Wolcott (94) and Woodworth (96); on the
freshwater fauna of the central region Eigenmann, Hart,
Hempel, Kofoid (96b, 98), Woodworth (97), and others;
further south Herrick (95), Turner (94) and Seurat; on the
plains toward the west Brewer and Ward (98); in the mountains
S. A. Forbes (98), and on the island of Hayti, Richard (95a)
record the work of the period under consideration.

Viewed from the hydrographic standpoint, freshwater or-
ganisms may be discussed with reference to the particular envi-
ronments which each type of water basin affords; one may
distinguish roughly the brook, river, swamp, pond and lake as
types of environment. These have been very unequally studied
as accords with the difticulty and probable results of the inves-
tigation. Stockmayer (94) has given a brief summary of the
general biologic aspect of the life of the brook, or in fact of
water in general, and of the problems to be solved by a station
located in a region rich in brooks; such a station is certainly a
great desideratum in freshwater work. No record appears of
work done on such a body of water.

The importance of studies on a river have been emphasized

320 HENRY B. WARD:

by Forbes (94, 97) and the particular problems with which one
has to deal in such a location. Under the direction of the
same investigator there has been opened on the Illinois River
a station which is devoted primarily to the problems of a river
system. Some of the results are given in the papers of Hart,
Hempel and Kofoid. Lauterborn (98, 94) and others have
done some work on the fauna of a river, and recently the topic
has received more attention. Schroder (97a, 98a) finds in rivers
the phytoplankton much in excess, the diatoms constituting the
ruling forms. In shallow ponds with not too strong an inflow
the zooplankton is far richer than in streams where it decreases
with increasing current. Zacharias (98a) shows that the potamo-
plankton is formed in plant-grown bays on the river shore, and
multiplies perhaps in slow-flowing streams. Zimmer (98) finds
that the character of the potamoplankton varies with the hight
of the water. He distinguishes (1) autopotamic forms which
find their conditions of existence only in flowing water. These
include at most very few animals. (2) Eupotamic forms, living
either in standing or flowing water, including most species of
the river plankton. (3) Tychopotamic forms, torn by chance
from quiet waters in which they live normally, and finding no
possibility of reproduction in the current. The potamoplank-
ton is very poor both in species and individuals as compared
with the limnoplankton. The Rotatoria constitute its chief
element, adult Crustacea are rare, and only one protozoon has
been observed. It is interesting to note that in a lake of the
Jura, Zschokke (94) records that the variations of level and the
strong current give it partly the character of a river. Here
the littoral zone is almost barren but the limnetic fauna rich
in species though poor in number of individuals.

No specitic report is on record during this period concerning
the investigation of a swamp. The closest resemblance to
such conditions are presented by Lake Nurmijarvi (Stenroos,
98) which possesses in fact a maximum depth of one meter.
Here could be distinguished nevertheless the characteristic re-
gions of the pond or lake fauna. The extreme richness of such

RECENT FRESHWATER INVESTIGATIONS 321

shallow bodies of water is indicated by a total of 460 species
recorded from this lake. The paper contains most valuable
observations on the characteristic fauna in each floristic region
and on its structural and ecological peculiarities. Zacharias (98)
calls the floating fauna of shallow natural or artificial water
basins the heleoplankton and has studied it from a number of
places. The majority of limnetic forms recur here and certain
Rotifera rare or lacking in lakes are found in such basins.
Characteristic is also the abundant development of the micro-
phyta and of the Ceriodaphniae. Here also Bigney and Pitard
(97a). Fric and Vavra (94) treat of two ponds, of somewhat dif-
ferent character, and give a complete and clear picture of pond
life, and the changes it undergoes. Here also Ward (98). The
characters of a pond are precisely stated by Zacharias (98) who
has found in such water basins almost all the eulimnetic organ-
isms of true lakes. The Rotatoria are more numerous, and in
the phytoplankton the desmids are the chief faztor.

On the fauna of a lake many investigations have been made
within the past five years, and the profitless preparation of
mere faunal lists seems fortunately to have passed its maximum
since an increasing number of the later papers has considered
not merely the composition of the freshwater fauna or of one
of its graups, in the region studied, but also the biological re-
lations and the origin of the fauna. Among the large number
of lacustrine investigations of all degrees of completeness, only
the more extensive can be mentioned in this connection. The
monographic work of Forel on Laka Geneva, Switzerland, has
already been sufficiently characterized. Lake Plon, Holstein,
has also been extensively studied by Zacharias and his coad-
jutors. Garbini’s careful investigations on Lake Garda, Italy,
and those of Entz and his confréres on Lake Balaton, Hungary,
are also deserving of prominent mention. Schwarzsee, Bohe-
mia, under Fric, Miigglesee, Germany, under Frenzel, and
numerous other individual lakes in Europe have been subjected
to careful investigation with valuable results. In North
America Reighard has studied Lake St. Clair, Eigenmann
Turkey Lake and Ward the northern portion of Lake Michigan

21

322 HENRY B. WARD:

in conjunction with numerous colaborers. Birge has devoted
himself singly to Lake Mendota and Marsh to Green Lake.
Other investigators have turned their attention toward a
series of lakes or a given type of lake rather than toward
a single body of water. Thus Apstein (94) has achieved
valuable results from the study of Holstein lakes, Pero
has devoted himself to Swiss lakes in a single can-
ton and Hartwig to those of Brandenburg. But the
most scriking instance of this specialization is Zschokke
whose investigations on elevated lakes have established so
clearly the biological features of such locations that subsequent
studies have added only details to the general picture he has
painted. The results of this author are summarized in a final
paper (95) which presents further a comparison of the author’s
work with that already achieved in other regions. This paper
includes a careful study of two lake regions in the Alps, a
group of small sub-nival bodies of water in the Rhaeticon chain
and numerous lakes of Wallis near St. Bernard. Both a littoral
and°a limnetic fauna is present and in them most freshwater
groups are represented, though in European nival and subnival
lakes Helizoa, sponges, Bosmina, Isopoda and Decapoda are
wanting and mollusks are scantily represented. The bulk of
the Alpine freshwater fauna consists of resistent cosmopolitan
species which recur in part in lakes of high altitude elsewhere.
To these are added (1) here and there rare forms from the
plains, (2) pure mountain forms often of northern character,
(3) abyssal inhabitants of sub-alpine lakes which find a suitable
environment on the shores of elevated Alpine lakes. The com-
position of the lacustrine fauna varies from piace to place even
within a single mountain chain, but in general untavorable en-
vironment increases with the altitude. The limit of suitable
environment, i. e. the upper limit of animal life, lies at dif-
ferent altitudes in ditferent mountain ranges, but appears to be
higher in massive ranges than in neighboring chains of lesser
magnitude. The presence of certain forms adapted to the par-
ticular locality and the absence of other species imparts to the
scanty fauna of a mountain lake a decided individuality, often

!
|

RECENT FRESHWATER INVESTIGATIONS 323

apparently in strong contrast to that of a neighboring basin.
In an earlier paper (94) Zschokke presented the results of
studies on lakes in the Jura showing a typical mountain char-
acter. Previously de Guerne et Richard (93) had investigated
the limnetic fauna in the same region and (94) in the Pyrenees.
In the Cottian Alps Blanchard et Richard (97) found similar
faunal conditions. Here also Blanc, Pitard, Imhof (93),
Pugnat (97). The varying fauna in adjacent basins is explained
by the last mentioned author on the ground of variation in the ex-
posure and illumination of the water. Studer (93) attributed
the poverty of the limnofauna in the lake of Champex to the
excessive illumination of the shallow water in the absence of
shore and bottom plants. Imhof (95a) investigated the hori-
zontal and vertical distribution of the aquatic mollusca in the
Alps. They are more numerous in the territory of the Rhone
and the Po, and manifest in small and in elevated lakes a rapid
reduction in number. On the southern slope of the Alps Fuhr-
mann (95) finds the fauna of the elevated lakes similar, though
somewhat richer. In the Julian Alps Lorenzi (97) finds a cos-
mopolitan fauna in which the plankton consists of tychopelagic
forms alone. In the Riesengebirge according to Zacharias
(96g, 98c) the limnetic fauna is scanty but similar to that of the
Rhaeticon lakes studied by Zschokke., The species present are
typical cold water forms. The same poverty and cosmopolitan
cast in the fauna is reported by Fric and Vavra (97) who at-
tribute the scanty shore and bottom fauna to the lack of vege-
tation. The disappearance of certain elements in the fauna
can be traced definitely to the introduction of game fish. In
the Tatra lakes, Galicia, Wierzejski (95) found typical Alpine
conditions in the poverty of species in the abundance of cosmo-
politan forms and in the contrast in proximate basins of equal
altitude. The lakes show, however, as Daday (97) remarks,
notable richness of fauna even up to an altitude of 2,000 m.
Here also Richard (96a, 96c). In Syria Barrois (94) found an
unusually rich limnetic fauna of cosmopolitan Entomostraca
and Rotatoria. The Sea of Tiberius, though strongly saline,

has a pure lacustrine fauna.

324 HENRY B. WARD:

One of the earliest investigations on elevated lake regions
and the only one yet made in this country is that of Forbes (93) -
in Wyoming and Montana. Noteworthy is the careful study
of the entire environment and its influence on the fauna. In
this Forbes made valuable contributions to the general char-
acter of the fauna of elevated lakes which were utilized by
Zschokke in the paper already noted. Among the features
discussed by Forbes are the extreme poverty of the vertebrate
aquatic fauna, the ruling species being rather Amphipods, leeches
and insect larvee, great rarity of mollusks, the abundance of
Entomostraca, largely cosmopolitan species, and the sharp
contrast of the fauna in adjacent water basins. There exists
a deepwater fauna in many of these lakes, of which something
was ascertained. In general the fauna proved to be richer
than that of lakes at corresponding and even less elevation in
Europe. The influence of environment was well shown by
variations in the fauna, such as the abundance of mollusks in
a lake lying within a ljime formation and their rarity in all
other elevated waters.

Only one investigator has yet endeavored to group into re-
gions in accordance with their fauna, the lakes of any conti-
nental area. Zograf (96) divides the lakes of Russia into four
regions, based upon the distribution of the fish and crustaceans.
The first region includes the large water basins in the north-
western portion of Russia, the second surrounds the first, the
third includes the lakes of Central Russia and is little known,
and the fourth takes in the steppe lakes bordering upon the
south. Geological evidence supports this general classifica-
tion, the first three being in territory covered by glacial sheets
in different. periods and the last constitutes the remains of a
miocene sea covering southern Russia.

In discussing the distribution of the fauna within a single
body of water authors have regularly adopted Forel’s lacus-
trine regions and the majority have also made use of the
terms introduced by Pavesi to designate the plankton organ-
isms as eulimnetic or regular inhabitants of the open lake and
tycholimnetic or chance members of the same region. The

RECENT FRESHWATER INVESTIGATIONS 325

general composition of the plankton may be judged from the >
statement of Strodtmann (96) that about 80 organisms occur in
the plankton of Holstein lakes of which, however, less than 40
are usual or important. All authors agree in noting the limited
number of species which are found in the plankton and equally
regarding the extreme abundance of individuals which make
up its volume. These organisms, moreover, are not at all times
the same species but manifest certain variations to be noted
later. Among the species of animals which the plankton
contains the Rotatoria are said to be the most important.

The total amount of plankton taken in the vertical net or
plankton pump and preserved in some suitable fluid is esti-
mated in several ways. (1) After settling in graduated tubes
for twenty-four hours the volume is read off from the tube,
Apstein (94), Reighard (94), Ward (96). Or the volume is
measured in a centrifugal machine, Juday (97). (2) Under
suitable precautions the entire amount is weighed, Fric and
Vavra (94), Zacharias (95, 95b). Or a known quantity of a
haul, measured by the first method, is taken, weighed both
before and after incineration, and the amount of organic
material in the entire haul calculated, Ward (96a). (38) The
organisms in a definite portion of a haul are counted under
suitable precautions and the number of organisms in the entire
haul calculated therefrom. This method, first used by Hensen
in the ocean, has been applied to freshwater by Apstein (94,
96). Zacharias (94d) employed it in abbreviated form. An-
other simplified form is given by Birge (95a).

There is no known relation between the results obtained by
these different methods and consequently no comparison can
be made between the results obtained by one method and those
obtained by another. Furthermore while the work of one ob-
server at a given time is capable of comparison with that done
at another, it seems perfectly clear that the work done by one
observer can not be directly compared with that done by another
even if the same method is employed. Difficulties in this con-
nection are noted by Kofvoid (97), Reighard (98) and others.

326 HENRY B. WARD:

Apstein (94) would divide lakes into two classes, plankton
rich and plankton poor, the first characterized by an abun-
dance of Clathrocystis and absence or rarity of Dinobryon, and
the second by reverse conditions. This classification is ques-
tioned Reighard (94), Zacharias (94) and Strodtmann (96) on
the basis of investigations in other lakes. The total amount
of plankton is believed by Steck (93) to depend on the length
of the shore line, and Reighard (94) also regards this as an im-
portant factor. Many observers have noted that there is in
general proportionally less in a larger than in a smaller lake,
and this has been found by Reighard (94a), Hofer (95), Walter
(95), Zacharias (95b), Strodtmann (96) and others to be capable
of more precise statement in the principle that the amount of
plankton per cubic meter of water varies inversely as the depth.
Other factors affect the development of the plankton, chief
among them being light, (Stenroos, 98), transparency of the
water, (Steck, 93), and temperature, (Zschokke, 95). Walter
(95) emphasizes also the relation between the depth and the
area of the lake.

In Norwegian lakes presenting a great variety of conditions
as to altitude, depth and rapidity of change in water contained
therein, Huitfelt-Kaas was able to show that shallow waters are
especially favorable for the development of the plankton while
deep basins are under otherwise like conditions notably poorer.
This is true only in summer and is probably controlled largely
by temperature conditions. Even more important, however,
is the drainage area of the lake and the proportionate inflow
and outflow, so that in basins with rapid change in water much
less plankton is found than in more stable lakes. Here it is
evident that a shallow lake may be even less favorable for.
the development of the plankton than a deeper one by virtue
of the greater instability associated with a limited volume.

On the question of horizontal distribution Apstein (94),
Reighard (94a) and others have maintained the existence of uni-
formity. Zacharias was inclined to question this (94c, 94d)
but has since then changed his views(95c). In the case of re-
cent observers who have noted nonuniformity in distribution

RECENT FRESHWATER INVESTIGATIONS 327

(Pitard, 97, Garbini, 98a) and particularly the presence of a
greater amount near the shore*, it is probable that proper re-
gard was not paid to depth and that there really exists no con-
siderable difference. Uniformity of horizontal distribution has
been shown to be modified by large inflow and by the existence
of areas more or less separated from the main body of the lake,
by shallows, or in deep bays (Huitfelt-Kaas, Zacharias. )

Regarding vertical distribution, Hofer (95) is alone in
placing 35 m., or in one case 65 m., as the lower limit of the
plankton. Other observers have noted no such limit and
Ward (96b) found plankton even down to 130 m., although he
shows that in comparison with the upper portions of the water
the deep stratum, 25 m. to the bottom, contains very little
plankton.

All investigators agree that the upper strata of the water
contain proportionately more plankton than any below. Reig-
hard (94) found at a depth of 5 m. that half the plankton oc-
curred in the upper one and one-half meters of water. Apstein
(94) and Ward (96) show that much more is found in the sur-
face 2m. than in any equai stratum below this. From enu-
meration of the Crustacea alone, Birge (97a) demonstrates that
in water having a total depth of 18 m. during the summer 45
per cent is found in the upper 3 m., 25 to 30 per cent in
the 8-6 m. level, 15 to 18 per cent in the 6—9 m. level, leaving
only 8 to 12 per cent for the lower half of the water. In the
fall and winter, however, the distribution of the Crustacea is
nearly uniform.

France (94) found in Lake Balaton a regular diurnal migra-
tion of at leasta part of the plankton, governed by light and
storm. Zacharias (95) was unable to find any such movement
of the plankton in Lake Plon. It is, however, confirmed for
Lake Balaton by Daday (97c) in his investigations on the lim-
netic Crustacea. Marsh (97) and Birge (95a) are positive that
it does not exist in the lakes which they studied. Pitard

* Two observers make directly contrary statements in this respect
concerning the same lake (Blanc, 95, and Pitard, 97).

328 HENRY B. WARD:

(97c, 97d) notes the much greater amount of plankton in the sur-
face stratum at night than can be found during the day when a
large amount is first met at 5 m. and the maximum at 10 m.
Birge (97a) on the basis of precise enumeration is able to show
concerning distribution in the upper meter of water that (1)
on calm, sunny days the upper 10 cm. of the lake may be al-
most devoid of Crustacea, while at a depth of 50 cm. the
numbers are considerable and may be very great; (2) the upper
meter is populated largely by immature Crustacea; (3) in
stormy and cloudy weather the Crustacea approach nearer the
surface though the number in the upper 10 cm. is always less
than at 50 em.; (4) at night the young become more evenly
distributed in this layer and the adults rise from below the 1
m. level towards the surface. Though this is only necessarily
true of the single lake studied, it must be said that the obser-
vations far exceed in accuracy of data any others yet published.

The vertical distribution of the plankton as a whole is, how-
ever, often quite different from that of the individual species.
Data regarding these are given by many investigators, none of
whom equal Marsh (97) and Birge (97a) in accuracy and
amount of evidence presented.

In studying the seasonal distribution of the plankton Apstein
(94) found the existence of a minimum in February in contrast
with a summer maximum. Zacharias (96f) shows that the
monthly mean remains much the same in different years, and
gives (96h) a set of records covering hauls made at a definite
point every ten days throughout the year. These give a min-
imum during the winter, a small maximum in May and another
greater in amount in August; both the rise to the maximum
and the decline from it are very rapid. Huitfeldt-Kaas finds
a single maximum in Norwegian lakes in July-August, and a
winter minimum in January-February. The approach to the
latter is a gradual one, but the former exhibits a rapid rise
and fall within a brief period. Here also Sernow.

For Entomostraca, Scourtield (93) places the maximum in
September, while Birge (97a) finds a spring maximum in May,
followed by a rapid deciine to the early summer depression in

RECENT FRESHWATER INVESTIGATIONS 329

June; then a midsummer maximum in July, a late summer
minimum in August and an autumn maximum in September or
October, followed by a decline to the winter minimum of
December to April.

The seasonal distribution of individual organisms has been
studied by a host of observers, prominent among whom is
Zacharias. In the first report of the Plon station (93) records
of certain species are given and others are added in each sub-
sequent volume. Calkins (93a) notes a definite culmination
for each organism, no two falling at the same time, though
most occur during the summer. The diatoms find a maximum
in the spring with low temperature of the water, the Cyanophy-
ceae at the end of the hot season with a high temperature of
the water and the algae in general at the time of the fall over-
turning. Zacharias (95d) and others find a considerable agree-
ment in the periodicity of organisms in successive years, while
Birge (97a) looks upon the periodicity as really biennial.

At Plon Zacharias (96h) is able to distinguish a winter and a
summer plankton and also for a brief period a fall and spring
plankton. In October and November the Copepoda rule so
that there is nearly a pure copepod plankton; from March to
May the diatoms are almost alone and in enormous numbers.
This is related to temperature as Schroder (98a) shows that in
colder alpine lakes and in streams the diatoms rule while in
ponds and lakes of higher temperature their place is taken by
the Schizophyceae. Precise data on the seasonal distribution
of different Crustacea are contained in the work of Marsh (97)
and Birge (97a) who have traced individual species through
long periods.

Lauterborn (98) has made observations of importance on the
limnetic Rotatoria—nearly half are eurythermic, or perennial;
about the same number are stenothermic of the summer variety
and only two stenothermic with preference for the winter tem-
perature. The summer and winter forms are all monocyclic,
while the perennial species are dicyclic or polycyclic, i. e.
producing males and ‘‘winter eggs”? two or more times yearly.

330 HENRY B. WARD:

In dicyclic forms the first sexual period falls in the spring and
the second in the fall.

Lundberg and Stingelin (97) discuss seasonal dimorphism
among Cladocera and shows that in some instances the suc-
cession of species is actually only a succession of broods.
Lauterborn (98a) shows great variations among Rotifera at dif-
ferent times of the year.

The extreme change in environment in the case of those lakes
which are frozen in winter has attracted the attention of
numerous observers to the life of the water at that time. Ac-
cording to the observations of Lauterborn (94) the microfauna
under the ice is rich in species and often in individuals; even
the limnetic fauna endures through the winter, some species in
large numbers. Certain Rotatoria are found in summer only,
and some Protozoa in winter only. However, accordingly to
Zacharias (94e)in Lake Plén, the Protozoa are the first to dis-
appear, then the Rotatoria, the Crustacea reaching a minimum
in February and March. ‘The periodicity of these forms is, he
believes, ruled not by temperature but by the surface and
depth of the water basin. In Finland also, Levander (94)
finds a rich limnetic fauna, consisting of various groups,
which persists under the ice of lakes and ponds. Of Cladocera,
according to Stingelin (95), most forms persist through the
winter though those with ephippia disappear, and many forms
manifest a marked seasonal dimorphism which as yet has been
worked out in only a few species. The investigations of Birge
(97a) show that 7 out of the 11 limnetic species of crustacea in
Lake Mendota are perennial and present in considerable num-
bers in the winter plankton, and these numbers are singularly
uniform from January to March with a minimum near the first
of this period. The Rotifera and the phyto-plankton are also
regularly present in this period and become abundant before
the breaking up of the ice. Hartwig (98b, cf. 98a) gives
precise data for another lake concerning the occurrence and
abundance of numerous winter species. Here also Lampert (96).
Sundvik believes that the fish may in some cases pass the

RECENT FRESHWATER INVESTIGATIONS oo

winter dormant while frozen in the ice of small ponds which
are entirely congealed.

Wesenberg-Lund (96) emphasizes the adaptations to the
climatic conditions of freshwater existence, particularly to the
ice, which are necessary in organisms coming from the sea.
This necessity is most evident for surface forms and is mani-
fested in the formation of winter eggs and winter buds. Land
animals must undergo modifications particularly in the organs
of respiration to fit them for an aquatic life.

In reference to the littoral fauna as a whole only a few scat-
tered notes are at hand. Various authors have attributed the
richness of a lake fauna to the development of the littoral area.
Reighard (94a) has expanded the idea to a considerable extent.
Others have attributed to the opposite cause the poverty of a
lacustrine fauna as Ward (96d) in the case of Pine Lake. In
this connection it has been frequently pointed out that the
development of the littoral flora is an exceedingly important
factor. On the whole, but little attention has been paid to the
littoral fauna as a whole although isolated groups of organisms
from it have been carefully studied. When the reverse has
been true, the results attained are rather striking. Thus Entz
(97) and his colleagues in the investigation of Lake Balaton
found an exceedingly rich littoral fauna, and some progress
was made in the distinction of shore ‘‘formations” and the
characteristic fauna of each. Thus Francé (97) distinguished
as protozoan formations, the peat bogs, the muddy shore with
reeds, the bottom mud, the sandy and rocky shore, and the
plankton.

The investigation of underground waters has received some
attention. In New Zealand, Chilton (94) discovered in sub-
terranean streams many forms also common in surface waters,
but all pale and transparent. In all the Crustacea save one,
eyes were entirely lacking, and in that one no rétinal pigment
was present. On the other hand, the antennae and other ap-
pendages were noticeably elongated. In the caverns of the
Adelsberg, Schmeil (94) noted that the subterranean Entomos-
traca were colorless or pale in contrast with similar forms from

Ty) HENRY B. WARD:

suriace waters. In the former eyes were present to be sure, but
the pigment was much reduced. According to Garbini (96)
subterranean forms present these same differences in color from
individuals of the species found at the surface but are further
distinguished by diminutive size and weakness. Only two
species were found which were characteristically subterranean.
Lauterborn (94a) notes that much the same species are present
on Heligoland in a dark closed well as in an open light one.
The fauna was here very scanty. Here also Lorenzi (98).
Packard (94) and Lendenfeld (96) have given summaries of
our knowledge regarding cave animals with frequent references
both morphological and ecological to the freshwater fauna of
such localities. The observations of Garbini (96) were made
largely on material from water-pipes. Whipple (98a) has made
similar studies in Massachusetts. Here also Viré.
Though numerous experimental researches have been made on
the ability of animals to become acclimatized to higher temper-
atures, there have been few observations on the forms which

occur under similar conditions in thermal springs. Both
Bruner (95) and Kellicott (97a) record species collected from
boiling springs, but without more precisc data concerning con-

ditions.

The importance of the plankton as fish food was pointed out
by Zacharias (93a) and Fric and Vavra (94) and discussed in
detail in connection with the food relations of the water by
Reighard (94) and Ward (95). Here also Field (97).

Walter (95) demonstrated by statistics the proportional re-
lation in fish ponds between the amount of plankton and the
growth of the young fish. Kochs (92) found that Entomostraca
could be enormously multiplied by the use of fertilizers in the
water, and Zacharias (97) reports that the fertilization of fish
ponds doubles the amount of plankton present. Variations in
the fertility of different water basins call for more precise
investigation and for the selection of suitable areas for inten-
sive aquaculture as in agriculture. Here also Hofer (96).

Istvanffy (94) shows that the diatoms are an important
source of food supply to the young fish, but that the species of

RECENT FRESHWATER INVESTIGATIONS 333

diatoms in question are those which grow on the shore plants
and only rarely the plankton forms. Strodtmann (97) has un-
dertaken valuable statistical investigations on fish food accord-
ing to which certain species are clearly plankton eaters while
others depend upon littoral forms for food. Here also Walter
(96b), Grevé (97), Dréscher (97a). Recently, Brockmeier (93)
has observed that in some instances gastropods make direct use
of the plankton as food.

The problem of the origin of the freshwater fauna has been
attacked from many sides. Of a general character may be
noted the discussion of Forel (94) who holds that the littoral
fauna has come by immigration from the marsh and river,
the limnetic has been brought in by birds largely and the
abyssal has been differentiated in the lake itself. The distri-
bution of freshwater animals according to de Guerne (93) is
influenced (1) by geographic reasons, (2) by zoologic features
of the organism. Even to the weakest a current forms no
barrier.

_ A number of observers have studied brackish water basins
and the modifications in transition from marine to freshwater
conditions. Levander (94a) found in an inlet of the sea typical
marine and brackish water forms together with those of the
freshwater in about equal numbers. Field (97) studied a long
pond manifesting all degrees of salinity and found the greatest
number of forms near the point of mean salinity. The forms,
however, were more like the hali- than the limno-plankton.
An increase in size of various species on prolonged stay in
brackish water indicates one possibility in the production of
species. Butschinsky (96) noted the mixed character of the
fauna in somewhat similar brackish lakes and its variation with
changes in the concentration of the salt. LLemmermann (98)
investigated a strand lake which had been dammed and in
which the salinity was constantly decreasing. The plankton
which was notably rich manifested some irregularities traceable
to the variable salt content of the water and certain species
were localized at various places.

334 HENRY B. WARD:

According to Scharff (95) the fauna of Ireland has come by
direct extension from Scotland and Wales, with which the con-
nection previously existing broke down during the pleistocene
period. Hanitsch (95) holds, however, that among the fresh-
water sponges three of the six species are American. The
importation occurred by means of gemmules borne on floating
pieces of wood in the Gulf Stream, or indirectly by mi-
grating birds through Greenland. The failure of these species
to spread further is explained on the ground of their inability
to compete with native species.

Simroth (96) believes that a secondary adaptation of many
land plants and animals has followed upon their remigration
into fresh water. Such groups as Hydrachnids show clear evi-
dence of a land life. Fresh water has been furthermore a place
of refuge for many ancient forms such as the Ganoids, the
Dipnoi and the Branchiopoda. Here also Guppy.

Beddard and Lankester show how tropical animals act-
ually are transported from place to place on aquatic plants.
Garbini (95b) has obtained positive evidence of passive trans-
portation of freshwater animals in that ten species representing
seven groups were actually collected in transit on mammals,
birds, amphibians and aquatic insects, thus evincing the impor-
tant rdle of these forms in the dispersion of the aquatic fauna. |
Schewiakoff (93a) rightly regards currents of air and water and 4
actively migrating atimals as the efficient means of distribu- a
tion for protozoa. Their successful introduction depends ac- ;
cording to Francé (97) not on meteorological conditions but -on
hydrological surroundings and on associated plant forms.
Kofoid (96b) states briefly the agencies, human and meteoro-
logical, important in dispersion.

The insufticiency of our knowledge and the impossibility of
drawing reliable conclusions regarding the distribution of 4
freshwater forms from the data at present on record are shown
by the statements of Hartwig (98) concerning rare Entomos-
traca and Jennings (98) on a supposed Asiatic rotifer.

The fauna of island lakes is believed by Richard (98) in the
case of the Canary Islands to be introduced in the egg stage by

RECENT FRESHWATER INVESTIGATIONS jan

birds and winds. Barrois also notes for the fauna of the
Azores that the cosmopolitan European species which are
present are characterized by resting stages of some sort, indi-
cating thus passive introduction by birds, water insects and

also by man. Such a population must have come gradually to
the islands.

The success with which plankton organisms may be trans-
ported during some stage in their life history is further evinced
by the ease with which some of these organisms can be raised
from dried mud, as done by Sars. Im this dried condition such
forms may remain years without losing power of development
under satisfactory conditions of environment. The older ex-

periments on that point have recently been confirmed by At-
kinson.

Among other agencies in dispersion must be noted the
glacial epoch and Voigt has followed out with great care the
effect upon the population of mountain brooks produced by the
glacial period and the present gradual supplanting of one spe-
cies by another.

According to Garbini (94) the limnetic fauna is a passive
importation from northern centers of dispersion, and Strodt-
mann (96) finds its extended uniformity both in Europe and
North America evidence of a previous common center in
northern polar regions from which the limnetic fauna spread
southward. The marine forms in Lake Garda Garbini (94)
believes are not a fauna relicta but either active migrants from
the Adriatic in most part or in a few cases passive transports
from the northern ocean.

Of especial interest on this question is the discussion con-
cerning the origin of the Nemertines, a purely marine group
with scattered freshwater species. According to Montgomery
(95a) these forms are of double origin, (1) direct migrants
through rivers to lakes and (2) relict forms in lakes. Their
recent origin is shown by variable structural features. Du
Plessis (95) would limit the former to rivers and to lakes never
occupied by the sea. Garbini (96a) thinks those of Lake

336 HENRY B. WARD:

9
Garda certainly not of a relict character but introduced pas-
sively from northern freshwater bodies.

The presence of a fauna relicta in African lakes has received
strong confirmation in the recent investigations of Moore on
Lake Tanganyika. This water basin contains a medusa, six
quasi-marine gastropods, two prawns, one crab and several pro-
tozoa, all marine in character and together constituting what
the author calls a halolimnic fauna. These geographically
isolated forms can not have made their way up the stream
flowing from the lake, in fact only one occurs on that shore
where the outlet empties into the sea; they cannot have been
carried overland, being deep water forms in part at least; they
are not like modern oceanic forms, but are similar to Jurassic
types. The common freshwater fauna was marked in geologic |
deposits of that period, hence it originated previous to these |
halolimnie forms which are consequently evidence of the .
contamination of the lake by a deep arm of the sea in what is i
geologically speaking no very remote period of time.

Giinther (94), speaking of the relict forms in Africa, notes
‘that the freshening of the water must have come very grad-
ually since evaporation is so rapid in the tropics. Rizzardi
(94) finds in a small crater lake a considerable fauna relicta
and concludes that this demonstrates the marine origin of the
water basin. In discussing another lake Garbini (93) had pre-
viously shown that such a fauna may owe its origin to passive
introduction. Hoernes (97) states still more sharply the argu-
ment in the case of Lake Baikal; a relict fauna does not neces-
sarily demonstrate the relict character of the water basin. The
former may have come, as in Lake Baikal, indirectly from the
marine source through other bodies of water, no longer in ex-
isteuce; and the connection was in this case more probably with
the Mediterranean than with the northern ocean.