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TRANSACTIONS
OL DEE
LIVERPOOL BIOLOGICAL SUCIETY. |
VOL. XVI
SESSION 1901-1902.
LIVERPOOL:
C. Tinztine & Co., PrintErRs, 53, VICTORIA STREET,
179'0'2',
574.0642
5 Maw, dy,
CONTENTS.
I.—PROCEEDINGS.
Office-bearers and Council, 1901-1902 .
Report of the Council .
Summary of Proceedings at the Ricci
Dinner of the Society .
Laws of the Society
List of Members .
Librarian’s Report (with list of Paes to ee .
Treasurer’s Balance Sheet .
I]. —TRANSACTIONS.
Presidential Address—‘‘ The Fauna indicated in the
Lower Keuper Sandstone of the i ene
of luiverpool.” By H. C. Brasuey.
Fifteenth Annual Report of the Liverpool Marine
Biology Committee and their Biological Station
at Port Erin (containing Guide to the Aquarium).
By Prof. W. A. H=rpmay, D.Sc., F.R.S.
Report on the Investigations carried on during 1901,
in connection with the Lancashire Sea Fisheries
Laboratory, at University College, Liverpool, and
the Sea Fisheries Hatchery at Piel, near Barrow;
containing ‘‘ Pleuronectes’? (L.M.B.C. Memoir
No. VIII). By Prof. W. A. Herpmay, F.RB.S.,
ANDREW Scott, JAMES JOHNSTONE, B.Sc., and F. J.
CoLe .
PAGE.
Wilile
Vill.
1X.
Ou,
XIV.
OD:
Ogi
eX
27
109
ry
Iv. LIVERPOOL BIOLOGICAL SOCIETY.
On some Red Sea and Indian Ocean _— i
ANDREW ScoTrT
“Chondrus”’ (L.M.B.C, Memoir No. D0. By Orto
VY. DarBISHIRE :
Snake Venoms, by W. Hanna, M.A., M.B..
The Place of Geology in Economics and Education.
By Prof. C. Lapworsu, F.R.S§.
PAGE.
397
429
ATI
485
OFFICE-BEARERS AND COUNCIL.
Gx- residents :
1886—87 Pror. W. MITCHELL BANKS, M.D., F.R.C.S.
1887—88 J. J. DRYSDALE, M.D.
1888—89 Pror. W. A. HERDMAN, D.Sc., F.R.S.E.
1889—90 Pror. W. A. HERDMAN, D.Sc., F.R.S.E.
1890—91 T. J. MOORE, C.M.Z.S.
1891—92 T. J. MOORE, C.M.Z.S.
189293 ALFRED O. WALKER, J.P., F.L.S.
1893—94 JOHN NEWTON, M.R.C.S.
189495 Pror. F. GOTCH, M.A., F.R.S.
1895—96 Pror. R. J. HARVEY GIBSON, M.A.
1896—97 HENRY O. FORBES, LL.D., F.Z.S.
189798 ISAAC C. THOMPSON, F.L.S., F.R.M.S.
1898—99 Pror. C. 8S. SHERRINGTON, M.D., F.R.S.
1899—1900 J. WIGLESWORTH, M.D., F.R.C.P.
1900—1901 Pror. PATERSON, M.D., M.R.C.S.
SESSION XVI, 1901-1902.
Aresvent ;
HHNRY C. BEASLEY.
ADJice- Presidents :
Pror. W. A. HERDMAN, D.Sc., F.R.S.
Pror. PATERSON, M.D., M.R.C.S.
Hon. Creasurer :
T. C. RYLEY.
Hon, Hibrarian :
JAMES JOHNSTONE, B.Sc.
Mon. Secretary?
JOSEPH A. CLUBB, M.Sc. (Vicr.).
Council :
J. W. ELLIS, M.D. JOSEPH LOMAS, F.G.S.
W. J. HALLS. JOHN NEWTON, M.R.C.S.
Rev. L. pe BEAUMONT KLEIN, J. SMITE Hh. Ss
D.Sc. I. C. THOMPSON, F.L.S.
W.S. LAVEROCK, M.A., B.Sc. J. M. TOLL.
Bev. T. S. LEA, M.A. J. WIGLESWORTH, M.D.,
ALFRED LEICESTER. | chal ie OF eae
REPORT of the COUNCIL.
Durine the Scssion 1901-1902 there have been seven
ordinary meetings and one field meeting of the Society.
The latter was held at Caergwrle, Flintshire, and was a
joint meeting with the Liverpool Geological Society.
The communications made to the Society have been
representative of almost all branches of Biology and the
exhibition of microscopic preparations and other objects of
interest has been well maintained at the meetings.
On the occasion of the lecture, entitled: —“ The place
of Geology in Education and Economics,” by Professor
Lapworth, F.R.S., of Birmmgham University, your
Council issued special invitations for the meeting, and a
large audience assembled.
The Library continues to make satisfactory progress, and
additional important exchanges have been arranged during
the year.
The Treasurer's statement and balance sheet are
appended.
No alterations have been made in the Laws of the
Society during the past session.
The members at present on the roll are as follows : —
Honorary Members: .2).0..c..7-.- ae 9
Ordinary’ Members....G) pe: 5. ee 49
Student. Members. ..........:4:...s-s0+008 25
SUMMARY of PROCEEDINGS at the MEETINGS.
The first meeting of the sixteenth session was held at
University College on Friday, October 11th, 1901.
‘The President-elect (Henry C. Beasley) took the chair
in the Zoology Theatre. _
1. The Report of the Council on the Session 1900-1901
fee eroceedings,” Vol. XV... p. vill.) was
submitted and adopted.
2. The Treasurer's Balance Sheet for the Session 1900-
fiicee~ Proceedings,’ Vol. XV., :p. xxx1.) was
submitted and approved.
3. The Librarian’s Report (see “‘ Proceedings,” Vol. XV.,
p- Xx.) was submitted and approved.
4. The following Office-bearers and Council for the
ensuing Session were elected :—Vice-Presidents,
Professor Herdman, D.Sc., F.R.S., and Professor
Paterson, M.D., M.R.C.S.; Hon. Treasurer, T. C.
Ryley; Hon. Librarian, James Johnstone, B.Sc. ;
Hon. Secretary, Joseph A. Clubb, M.Sc.; Council,
Dr. J. W. Ellis, W. J. Halls, Rev. L. de B. Klein,
D.Se., Rev. T. S. Lea, M.A., W. S. Laverock, M.A..,
B.Se., Alired Leicester, Joseph Lomas, F.GS.,
John Newton, M.R.C.S., Joseph Smith, F.L.S., I. C.
Thompson, F.L.8., J. M. Toll, and J. age
ed EH R.C.P
eeeeix, Henry C. Be clic delivered the Presidential
Address, entitled “The Fauna indicated in the
Lower Keuper Sandstone of our District” (see
“‘Transactions,’ p. 1). A vote of thanks was
proposed by Dr. Newton, seconded by Mr. Lomas,
and carried with acclamation.
Ke LIVERPOOL BIOLOGICAL SOCIETY.
The second meeting of the sixteenth session was held at
University College, on Friday, November 8th, 1901. The
President in the chair.
1. Professor Herdman submitted the Annual Report on
the work of the Liverpool Marine Biology
Committee and the Port Erin Biological Station
(see “ Transactions,’ p. 27).
The third meeting of the sixteenth session was held at
University College, on Friday, December 13th, 1901. The
President in the chair.
1. Prof. Lapworth, F.R.S., of Birmingham University,
lectured on “The place of Geology in Hducation
and Hconomics”’ (see “ Transactions,” p. 485).
2. Prof. Kendall, of Leeds, kindly gave an impromptu
lecture on “Rivers and River Action,’ while waiting
for Prot. Lapworth, who arrived late through train
delays.
——
The fourth meeting of the sixteenth session was held at
University College, on Friday, January 10th, 1902. The
President in the chair.
1. Mr. I. C. Thompson communicated a letter from
Prof. Herdman, giving interesting details of the
work of collecting Plankton while on his journey
to Ceylon.
2. Mr. J. Johnstone, B.Sc., communicated the Annual
Report of the investigations carried on during 1901,
in connection with the Lancashire Sea Fisheries
Committee, by Prof. Herdman, A. Scott, and
himself (see “ Transactions,” p. 109).
SUMMARY OF PROCEEDINGS AT MEETINGS. lle
The fifth meeting of the sixteenth session was held at
University College, on Friday, February 14th, 1902. The
President in the chair.
1. Dr. W. H. Broad exhibited and described an
Australian skeleton, and skulls of both the
Austrahan and Maori types.
2. Mr. F. J. Cole gave an interesting lecture on the
“ Evolution of the head of the flat fish,’ in which
he described the life-history of the Plaice, and
traced the probable track of the evolution of the
asymmetry of the head. ‘The lecture was illus-
trated by lantern slides.
The sixth meeting of the sixteenth session was held at
University College, on Friday, March 14th, 1902. The
President in the chair.
1. Mr. I. C. Thompson communicated a second letter
from Prof. Herdman, giving some further details
of his doings in Ceylon.
2. Prof. Paterson gave an interesting paper on the
“Morphology of the Sternum.”’ T'he lecture was
illustrated by a number of specimens illustrating
variations from the normal condition in the human
breast bone. An animated discussion followed
the reading of the paper.
The seventh meeting of the sixteenth session was held
at University College, on Friday, April 11th, 1902. The
President in the chair.
X11. LIVERPOOL BIOLOGICAL SOCIETY.
1. Dr. W. Hanna communicated a paper on “ Snake
Venoms” (see “ Transactions,” p. 471). A discussion
followed.
2. Mr. Andrew Scott’s paper on a collection of Copepoda,
made by Mr. H. C. Robinson in the Indian Ocean,
was communicated by the Hon. Secretary (see
‘Transactions,’ p. 397).
The eighth meeting of the sixteenth session was a Field
Meeting, held jointly with the Liverpool Geological
Society, at Caergwrle, Flintshire, on Saturday, June 7th,
1902.
1. After tea a short business meeting was held. On
the motion of Prof. Herdman from the chair, seconded
by Mr. J. Lomas, Dr. Caton was unanimously elected
President for the ensuing session.
DINNER TO PROF. HERDMAN, F.R.S., AND
MRS. HERDMAN.
Under the auspices of the Society, a large and repre-
sentative company assembled in the Adelphi Hotel,
Liverpool, on Tuesday evening, May 6th, at a dinner
held to do honour to Prof. and Mrs. Herdman.
Professor Herdman had just returned from an important
expedition sent out by the Colonial Office to investigate
the Ceylon Pearl Oyster Fisheries, with the object of
placing the industry on a more scientific basis, and
it was thought to be a fitting opportunity to testify to
Prof. Herdman a little of the esteem in which he is held
by the Biologists of Liverpool. The Lord Mayor and
SUMMARY OF PROCEEDINGS AT MEETINGS. X1ll.
Lady Mayoress graced the proceedings by their presence,
and the company included, in addition to the guests, Mr.
H. C. Beasley (President), Prof. Paterson (Vice-President),
Sir William Mitchell Banks, Dr. Carter, Mr. I. C.
Thompson, Mr. J. Lomas, Mr. J. A. Clubb (Hon.
Secretary), Mr. Hoyle (Owens College, Manchester), Dr.
Wiglesworth, Mr. Alfred Holt, Dr. Klein, Prof. Mackay,
Mr. Kermode (Ramsey) and others. After the loyal toasts,
Sir William M. Banks, in a graceful and witty speech,
proposed the health of Prof. and Mrs. Herdman, to which
the former responded. Although prevented from speaking
on the principal object of the expedition, viz., his work on
the pearl oyster, because the Government report had not yet
been presented, the learned Professor gave a most interest-
ing account of other sections of his work and of visits to
the notable “buried cities” of Ceylon, hidden in the jungle,
and to Adam’s Peak, the sacred shrine of both Moham-
medans and Buddhists. Other toasts were the “Lord
Mayor and Lady Mayoress,” proposed by Prof. Paterson ;
the “ Biological Society,’ coupling the name of the
President, Mr. Beasley, proposed by the Lord Mayor; and
the “ Visitors,’ proposed from the Chair, and responded
to by Mr. Hoyle, of Manchester. .
LAWS of the LIVERPOOL BIOLOGICAL
SOCIETY.
I.—The name of the Society shall be the “ LivErPoor
BiotocicaL Society,’ and its object the advancement of
Biological Science.
Il.—The Ordinary Meetings of the Society shall be held
at University College, at Seven o’clock, during the six
Winter months, on the second Friday evening in every
month, or at such other place or time as the Council may
appoint.
III.—The business of the Society shall be conducted by
a President, two Vice-Presidents, a Treasurer, a Secretary,
a Librarian, and twelve other Members, who shall form a
Council; four to constitute a quorum.
ITV.—The President, Vice-Presidents, Treasurer, Secre-
tary, Librarian and Council shall be elected annually, by
ballot, in the manner hereinafter mentioned.
V.—The President shall be elected by the Council
(subject to the approval of the Society) at the last Meeting
of the Session, and take office at the ensuing Annual
Meeting.
VI.—The mode of election of the Vice-Presidents,
Treasurer, Secretary, Librarian, and Council shall be in
the form and manner following: —It shall be the duty of
the retiring Council at their final meeting to suggest the
names of Members to fill the offices of Vice-Presidents,
Treasurer, Secretary, Librarian, and of four Members who
LAWS. XV.
were not on the last Council to be on the Council for the
ensuing session, and formally to submit to the Society, for
election at the Annual Meeting, the names so suggested.
The Secretary shall make out and send to each Member of
the Society, with the circular convening the Annual Meet-
ing, a printed list of the retiring Council, stating the date
of the election of each Member, and the number of his
attendances at the Council Meetings during the past
session ; and another containing the names of the Members
suggested for election, by which lists, and no others, the
votes shall be taken. It shall, however, be open to any
Member to substitute any other names in place of those
upon the lists, sufficient space being left for that purpose.
Should any list when delivered to the President contain
other than the proper number of names, that list and the
votes thereby given shall be absolutely void. Every list
must be handed in personally by the Member at the time
of voting. Vacancies occurring otherwise than by regular
annual retirement shall be filled by the Council.
~ VII.—Every Candidate for Membership shall be pro-
posed by three or more Members, one of the proposers
from personal knowledge. The nomination shall be read
from the Chair at any Ordinary Meeting, and the Candi-
date therein recommended shall be balloted for at the
succeeding Ordinary Meeting. Ten black balls shall
exclude.
VIII.—When a person has been elected a Member, the
Secretary shall inform him thereof, by letter, and shall at
the same time forward him a copy of the Laws of the
Society.
IX.—Every person so elected shall within one calendar
month after the date of such election pay an Entrance Fee
of Half a Guinea and an Annual Subscription of One
XVI. LIVERPOOL BIOLOGICAL SOCIETY.
Guinea (except in the case of Student Members); but the
Council shall have the power, in exceptional cases, of
extending the period for such payment. No Entrance Fee
shall be paid on re-election by any Member who has paid
such fee.
X.—The Subscription (except in the case of Student
Members) shall be One Guinea per annum, payable in
advance, on the day of the Annual Meeting in October.
XTI.—Members may compound for their Annual Sub-
scription by a single payment of Ten Guineas.
XI1.—There shall also be a class of Student Members,
paying an Entrance Fee of Two Shillings and Sixpence,
and a Subscription of Five Shillings per annum.
XITI.—AIl nominations of Student Members shall be
passed by the Council previous to nomination at an Ordin-
ary Meeting. When elected, Student Members shall be
entitled to all privileges of Ordinary Members, except that
they shall not receive the publications of the Society, nor
vote at the Meetings, nor serve on the Council.
XIV.—Resignation of Membership shall be signified wn
writing to the Secretary, but the Member so resigning shall
be liable for the payment of his Annual Subscription, and
all arrears up to date of his resignation.
XV.—The Annual Meeting shall be held on the second
Friday in October, or such other convenient day in the
month, as the Council may appoint, when a report of the
Council on the affairs of the Society, and a Balance Sheet
duly signed by the Auditors previously appointed by the
Council, shall be read.
XVI.—Any person (not resident within ten miles of
Liverpool) eminent in Biological Science, or who may have
rendered valuable services to the Society, shall be eligible
LAWS. XVII.
as an Honorary Member; but the number of such Members
shall not exceed fifteen at any one time.
XVII.—Captains of vessels and others contributing
objects of interest shall be admissible as Associates for a
period of three years, subject to re-election at the end of
that time.
XVIII.—Such Honorary Members and Associates shall
be nominated by the Council, elected by a majority at an
Ordinary Meeting, and have the privilege of attending and
taking part in the Meetings of the Society, but not voting.
XIX.—Should there appear cause in the opinion of the
Council for the expulsion from the Society of any Member,
a Special General Meeting of the Society shall be called
by the council for that purpose; and if two-thirds of those
voting agree that such Member be expelled, the Chairman
shall declare this decision, and the name of such Member
shall be erased from the books.
XX.—EHvery Member shall have the privilege of intro-
ducing one. visitor at each Ordinary Meeting. The same
person shall not be admissible more than twice during the
same session.
X XI—Notices of all Ordinary or Special Meetings shall
be issued to each Member by the Secretary, at least three
days before such Meeting.
XXII.—The President, Council, or any ten Members
can convene a Special General Meeting, to be called
within fourteen days, by giving notice in writing to the
Secretary, and stating the object of the desired Meeting.
The circular convening the Meeting must state the pur-
pose thereof.
XXIII.—Votes in all elections shall be taken by ballot,
XViil. _ LIVERPOOL BIOLOGICAL SOCILTY.
and in other cases by show of hands, unless a ballot be
first demanded.
XXIV.—No alteration shall be made in these Laws,
except at an Annual Meeting, or a Special Meeting called
for that purpose; and notice in writing of any proposed
alteration shall be given to the Council, and read at the
Ordinary Meeting, at least a month previous to the meet-
ing at which such alteration is to be considered, and the
proposed alteration shall also be printed in the circular
convening such meeting; but the Council shall have the
power of enacting such Bye-Laws, as may be deemed
necessary, which Bye-Laws shall have the full power of
Laws until the ensuing Annual Meeting, or a Special
Meeting convened for their consideration. .
BYE-LAWS.
1. Student Members of the Society may be admitted as
Ordinary Members without re-election upon payment of
the Ordinary Member’s Subscription; and they shall be
exempt from the Ordinary Member’s Entrance Fee.
2. University College Students may be admitted as
Student Members of the Society for the period of their
college residence, on the single payment of a fee of Five
Shillings and an entrance fee of Two Shillings and Six-
pence. ,
LIST of MEMBERS of the LIVERPOOL
ELECTED.
1899
1898
1886
1886
1888
1894
1889
1886
1886
1900
1897
1900
1886
1886
1901
1896
BIOLOGICAL SOCIETY.
SHSSION 1901-1902.
A. Orpinary MEMBERS.
(Life Members are marked with an asterisk.)
Annett, Dr. H. J., University College, Liverpool.
Armour, Dr. T. R. W., University College, Liver-
pool.
Banks, Sir W. Mitchell, M.D., F.BR.C.S., 28,
Rodney-street.
Barron, Prof. Alexander, M.B., M.R.C.S., 34,
Rodney-street.
Beasley, Henry C., Prestpent, Prince Alfred-
road, Wavertree.
Boyce, Prof., University College, Liverpool.
Brown, Prof. J. Campbell, 8, Abercromby-square.
Caton, R., M.D., F.R.C.P., Lea Hall, Gateacre.
Clubb, J. A., M.Se., Hon. Secretary, Free Public
Museums, Liverpool.
Cole, F. J., University College, Liverpool.
Dutton, Dr. J. Everett, 44, Upper Parlament-
street, Liverpool.
Ellis, Dr. J. W., 18, Rodney-street, Liverpool.
Gibson, Prof. R. J. Harvey, M.A., F.L.8., Univer-
sity College.
Halls, W. J., 35, Lord-street.
Hanna, W., M.A., M.B., 25, Park-way, Liverpool.
Haydon, W. H., 8, Amberley-street.
XX.
1900
1886
1893
1897
1900
1898
1886
1895
1901
1894
1886
1896
1886
1888
1900
1894
1894
1886
1897
1890
1887
1897
1900
LIVERPOOL BIOLOGICAL SOCIETY.
Hayward, Lt.-Col. A. G., Rearsby, Blundellsands.
Herdman, Prof. W. A., D.Sc., F.R.S., Vicr-Prestr-
DENT, University College.
Herdman, Mrs., B.Sc., Croxteth Lodge, Ullet-
road, Liverpool.
Holt, Alfred, Crofton, Aigburth.
Horsley, Dr. Reg., Stoneyhurst, Blackburn.
Johnstone, James, B.Sc., Hon. Lrerartan,
Fisheries Laboratory, University College,
Liverpool.
Jones, Charles W., Allerton Beeches. :
Klein, Rev. L. de Beaumont, D.Sc., F.L.S., 26,
Alexandra Drive.
Layton, P., Glendale, Leyfield-road, West Derby
Lea, Rev. T. S., M.A., St. Ambrose Vicarage,
Widnes.
Leicester, Alfred, Scot Dale, New Ferry.
Laverock, W. S., M.A., B.Sc., Free Museums,
Liverpool.
Lomas. J., Assoc. N.S.S., F.G.S., 18, Moss-grove,
Birkenhead.
Newton, John, M.R.C.S., 2, Prince’s Gate, W.
Nisbet, Dr., 175, Lodge Lane, Liverpool.
Paterson, Prof., M.D., M.R.C.S., Vicz-PRESIDENT,
University College, Liverpool.
Paul, Prof. F. T., Rodney-street, Liverpool.
*Poole, Sir James, J.P., Abercromby-square.
Quayle, Alfred, 7, Scarisbrick New-road, South-
port. ‘
*Rathbone, Miss May, Backwood, Neston. |
Robertson, Helenus R., Springhill, Church-road, —
Wavertree. }
Robinson, H. C., Holmfield, Aigburth.
Rylands, Ralph, 2, Charlesville, Claughton.
1887
(1894
1895
1900
1886
1895
1886
1889
1888
1886
1891
1896
LIST OF MEMBERS. XX.
Ryley, Thomas C., Hon. Treasurer, 10, Waver-
ley-road.
Scott, Andrew, Piel, Barrow-in-Furness.
Sherrington, Prof., M.D., F.R.S., University Col-
lege, Liverpool.
Smith, Mrs., 14, Bertram-road, Liverpool.
Smith, Andrew T., 5, Hargreaves-road, Sefton
Park.
Smith, J., F.L.S., The Limes, Latchford, War-
rington.
Thompson, Isaac C., F'.L.8., 58, Croxteth-road,
Thornely, Miss L. R., 17, Aigburth Hall-road.
Toll, J. M., 49, Newsham-drive, Liverpool.
Walker, Alfred O., J.P., F.L.S., Ulcombe Place,
Maidstone. |
Wiglesworth, J., M.D., F.R.C.P., County Asylum,
Rainhill.
Willmer, Miss J. H., 20, Lorne-road, Oxton, Bir-
kenhead.
B. Srupent MEMBERS.
Bramley-Moore, J., 138, Chatham-street.
Carstairs, Miss, 39, Lily-road, Fairfield
Drinkwater, HE. H., Rydal Mount, Marlboro’-road,
Tuebrook.
Elder, D., 49, Richmond Park, Liverpool.
Graham, Miss Mary, Ballure House, Gt. Crosby.
Hannah, J. H. W., 55, Avondale-road, Sefton Park.
Harrison, Oulton, Denehurst, Victoria Park, Wavertree.
Hick, P., 3, Victoria Drive, Rock Ferry.
Hunter, S. F., Westminster Park, Chester.
Jefferies, F., 45, Trafalgar-road, Egremont.
Jones, H., University College, Liverpool.
XX. LIVERPOOL BIOLOGICAL SOCIETY.
Knott, Henry, 11, Brereton Avenue, Liverpool.
Law, Arthur, B.Sc., University College, Liverpool.
Lawrie, R. D., Sunnyside, Woodchurch Lane, Birkenhead.
Lloyd, J. T., 43, Ullet-road, Sefton Park.
Mann, J. C., University College, Liverpool.
Mawby, W., Clumber, Prenton-road, E., Birkenhead.
Pearson, J., 43, Dryden-road.
Stallybrass, C. O., Grove-road, Wallasey.
Scott, G. C., 65, Croxteth-road.
Smith, G., University College, Liverpool.
Smith, C. H., University College, Liverpool.
Tattersall, W., 290, Stanley-road, Bootle.
Woolfenden, H. F., 6, Grosvenor-road, Birkdale.
C. Honorary MEMBERS.
S.A.S. Albert I., Prince de Monaco, 25, Faubourg St.
Honore, Paris. ;
Bornet, Dr. Edouard, Quai de la Tournelle 27, Paris.
Claus, Prof. Carl, University, Vienna.
Fritsch, Prof. Anton, Museum, Prague, Bohemia.
Giard, Prof. Alfred, Sorbonne, Paris.
Haeckel, Prof. Dr. E., University, Jena.
Hanitsch, R., Ph.D., Raffles Museum, Singapore.
Solms-Laubach, Prof-Dr., Botan. Instit., Strassburg.
REPORT of the LIBRARIAN.
TixcHANGES of publications have been arranged with the
following institutions : —
Basel—Ornithologischer Verein.
Munchen—Ornithologischer Verein.
Rennes—Société Scientifique et Medicale.
Roma—Societas Zoologica Italiana.
Zagreb—Societas Historica-Naturalis Croatica.
The condition of the Library demands serious attention.
Over one hundred new volumes are now received every
year, and during the last two years no money has been
forthcoming to provide for the binding of the books
received. A considerable number of volumes have
accumulated since the grants of £24 made by the Council
two years ago, and it is very necessary that these should
receive attention. A yearly grant of £10 would be
sufficient to bind the volumes added during the session
and those which have accumulated. The Library is now
becoming a very valuable one, and is worth this
expenditure.
Lists of the publications added to the Library during
the Session 1901-2, and of the Societies and Institutions
on the Exchange List, are appended.
1.— PUBLICATIONS ADDED TO THE LIBRARY DURING.
THE SEsston 1901-2.
Adelaide, Trans. Roy. Soc. South Australia. Vol. XXV., pts. 1 and 2.
1901.
Albany (U.S.A.), Bull. Buffalo Soc. Nat. Sci. Vol. 7., No. 1.
Guide to the Geology and Paleontology of Niagara Falls and
Vicinity. A.W. EHraban. 1901.
XXIV. LIVERPOOL BIOLOGICAL SOCIETY.
Amsterdam—Jaarb. Konink. Akad. Wetensch. For 1900-1901.
Amsterdam—Verhand. Konink. Akad. Wetensch. Ser. 2. Deel VIL.,
No. 4-6. 1900-1.
Amsterdam—Verslag Gew. Vergad. Wiss-en-Naturk afdeel. Deel IX.
1901.
Amsterdam—HEnglish Translation of above. 1901.
Amsterdam—Natuurk. Tijdschrift. Deel 60. 1901.
Baltimore (U.S.A.), Memoirs Johns Hopkins Univ. Biol. Labt. IV.—5.
1900. Univ. Cisculars, Vol. 21, No. 155. 7 1902:
Basel—Naturf. Gesellsch. Verhandl. Bd. 13, Heft 1—2, 1901.
Namenverzeichnis v. Sachsregister. Bd. 6—12. 1901.
Bergen—Crustacea of Norway. G.O. Sars, vol. 4; pts. 1—4. 1901.
Bergen, Bergens Mus. Aarbog. Heft 1. 1901.
Bergen, Bergen Mus. Meeresfauna von. Bergen. Heft1. 1901.
Berlin—Sitzungsber. K. Preussichen. Akad. Wiss. Pts. 1—53. 1901.
Berlin—Mittheil. Deutsch See-Fisch. Vereins. Bd. 17, Nos. 4—12.
Bd. 18, No.1. 1901-2.
Berlin—Zeitschr. £. Fischerei. Bd. 9, hefte 3-4. 1902.
Berlin—Notes de Geographie Biologique Marine. §.A.S. Albert I.,
Prince de Monaco.
Buenos Aires—Communicaciones Mus. Nac. T.1, nos. 8—10, 1901.
Bordeaux—Proces. Verb. Soc. Linn. 1900.
Bordeaux—Catalogue de la Bibliotheque. Fasc. 2, 1901.
Bonn, Verhandl. Naturhist. Ver. Jahrg.57. 2nd Halfte. 1900.
Bonn, Sitz. Niederrh. Ges. 2 Halfte. 1900.
Brussells—Acad. Roy de Belgique. Bull. Classe des Sciences. 1899-1900.
Brussells—Acad. Roy de Belgique. Annuaire. 1900-1901.
Caen—Bull. Soc. Linn. de Normandie (Ser. 5). Vol. IV. 1901.
Cambridge (U.S.A.)—Bull Mus. Comp. Zool., Harvard. Vol. 38
(Geol. Ser.). Vol. 35, No. 2-4, 1901; Vol. 36, No. 7-8, 1901
Vol. 37, No. 3, 1901.
Cambridge (U.S.A.)—Ann. Rep. Mus. Comp. Zool., 1900-1901:
Chicago, The Botanical Gazette. Vol. 31, Nos. 3-6; Vol. 32, 1901;
Vol. 33, No. 1, 1902.
Chicago, 6th Ann. Rep. John Crerar Library. 1900.
Chicago Field Columbian Museum—
Zoological Series. Vol. 2; Vol. 3, No. 1—3. 1901.
Geological Series. Vol. 1, No. 8. 1901.
Anthropological Series. Vol. 2, No. 4-5. 1900-1. Vol. 3, No. 1.
1901.
Report Series. Vol. 1, No.6. 1900.
Christiania, Forhandl. Vidensk-selskab. Aar. 1900-1901.
LIBRARIANS REPORT. XXV.
Chatham (N.B.), Proc. Nat. Hist. Ass. Miramichi. No.2. 1901.
Dublin—Sci. Proc. Roy. Dublin Soc. Vol. 9, pts. 3-4. 1901.
Dublin—Sci. Trans. Roy. Dublin Soc. Vol. 7, pts. 8-13. 1901.
Edinburgh—Proc. Royal Phys. Soc. Session 129. 1901.
Frankfurt—Bericht. Senckenb. Naturf. Gesellsch. 1901.
Freiburg, I. B.—Ber. Naturf. Ges. 11 Bd. Heft 3. 1901.
Geneva, Mem. Soc. de Physique et Nat. Hist. T. 32, Pt. 2. 1899-1901.
Glasgow—19th An. Rep. Scottish Fish. Bd. Pt. 3. 1901.
Gottingen, Nachr. k. Ges. Wissensch—
Gesch. Mitth. Heft 1-2. 1901.
Math.-Phys. Klasse. Heft 1. 1901.
Giistrow, Arch. Ver. Freunde Naturg. Mecklenburg. Jahr 5.
Abth. I.—ITI. 1900-1.
Haarlem—Archives Mus. Teyler. Vol.7. Ser.2. Pts. 2. Pts. 3-4. 1901.
Halle, Nova Acta Abh. k. Leop.-Catol. Deutschen Akad. Naturf.
PaemoemN oe. 1-3-bds: 68, 69) No. 38; Bd. 70, No: 3; Bd 74,
iNeweasaiad. 76; Bd. 77, No. 1-3; Bd. 78. 1895-1901.
Halifax, Proc. and Trans. Nova Scotian Inst. Sci. Vol. 10, Pt. 2. 1900.
Kobenhayn—Oversigt K. Danske Selsk. Forh. Nos. 2-6. 1901.
Kobenhayn—Mem. Acad. Roy. Lett. Sci. Denmark (Ser. 6, Sect. Sci.).
MoS INo} 8. 1901.
Kiel, Schriften Naturwiss. Ver. Schleswig-Holstein. Bd. 12, Heft 1,
1901.
Kiel und Leipzig, Wiss. Meeresuch. Kiel Komm, (N.F.). Bd. 4,
Abt. Helgoland. Heft 2. 1900. Bd. 5, Abt. Kiel. Heft 2. 1901.
Kyoto, Japan, Kyoto Imp. Uniy. Calendar. 1900-1.
La Haye—Arch. Neerlandaises. T. 4, Livrs. 2-5. 1901.
Lawrence (U.S.A.)—Kansas Univ. Quarterly. Vol. 10, No. 1-4. 1900-1.
La Plata—Contribuciones al conocimiento de la Geologia de Buenos
Aires. Publicaciones Universidad de La Plata. No.1. 1901.
Leeds, Trans. Yorkshire Nat. Union. Pts. 24—7. 1900-1.
Leipzig, Ber. Verhandl. k. Sachs. Ges. Wissensch. Bd. 53, I.—VI. 1901.
Leipzig, Jahresber. Furstlich Jablonowski’schen Ges. Marz. 1901.
Liverpool, Proc. Geol. Soc. Vol. 8, Pt. 4. 1900. Vol. 9, Pt. 1. 1901.
Liverpool, Bull. Liverpool Mus. Vol. 3, No.2. 1901.
London --The Naturalist, Nos. 532—41, 1901-2.
London—Journ. Roy. Micros. Soc. 1901, Pts. 3—6; 1902, Pt. 1.
London—British Mus. Cat. Cretaceous Bryozoa, Vol. 1. Jurassic
Bryozoa. 1899-1896.
London—Brit. Mus. Guide to Shellfish and Starfish Galleries. 1901.
London—Contributions to The Malacostracan Fauna of the Mediter-
ranean. A. O. Walker. 1901. (Presented by author.)
XXVI1. LIVERPOOL BIOLOGICAL SOCIETY.
London—Year-Book of Learned Societies.
Manchester, Trans. and Report Micros. Soc. 1900.
Madison (Wis., U.S.A.)—The Clays and Clay Industries of Wisconsin.
E. R. Buckley. Wisconsin Geol. and Nat. Hist. Survey Bull.
INGE Hemet. Le OO:
Melbourne—Proc. Roy. Soc. Victoria. Pts. 1—2, 1900. Pt. 1, 1901.
Monaco Resultats Campagnes Scientifiques. Fascs. 17-20. 1900-1.
Montpellier—Acad. Sci. Lett. (Ser. 2). T. 2, Nos. 5-7, 1898-1900:
ao Nons 190K
Moscow—Bull. Soc. Imp. Nat. 1900-1, Nos. 1—4; 1902, Nos. 1—2.
Montevideo, Anales Mus. Nac.T. 8, Nos. 20—21; T.4, Nos. 19—20. 1901.
Miinchen, Allgemeine Fish-Zeitung. Nos. 8—24, 1901 ; Nos. 1—5, 1902.
Mitinchen—Jahresber. II. Ornithol. Vereins. 1901.
Nancy—Bull. Seances Soc. Sci. (Ser. 3). T. 2, Fase. 3. 1901.
Nancy—Bull. des. Seances Soc. Sci. et de la Reunion Biologique.
Ser. 3. T.1. Fasc 4—6. 1900. T.2. Fase 1, 190K
Napoli, Rend. dell’ Accad. Sci. Fis. e Mat. Ser. 3a. Vol. 7, Fase.
3—12, 1901; Vol. 8, Fasc. 2, 1902.
New York, Mus. Brooklyn Inst. Arts and Sciences. Sci. Bull. Vol. 1,
IN@s dla UG,
Paris, C. R. Hebd. Soc. Biol. T. 53, Nos. 13—41, 1901; T. 54,
Nos. 1—7, 1902.
Paris, Bull. Scientifique. T. 33—34, 1900-1.
Paris, Bull. Soc. Zool. T. 25, 1900.
Paris, Mem. Soc. Zool. T. 13, 1900.
Paris, Bull. Mus. Hist. Nat. 1901, Nos. 1—8.
Philadelphia, Proc. Acad. Nat. Sci. Vol. 52, Pt. 3, 1901; Vol. 53, 1901.
Rennes—Bull. Soc. Sci. et Medicale. T.1i. to x., Nos. 1—8. 1892-1902.
San Francisco, Proc. California Acad. Sci. Zoology. Vol. 2,
Nos. 1—4, 6. 1899-1900.
Stavanger, Aars-hefte Stavanger Museum, for 1900, 1901.
Stockholm—Bihang. K. Svenska Vet. Akad. Vol. 26 (3-4). 1901..
Sydney—Rec. Australian Mus. Nos. 1—5. 1901.
Sydney—Reports Australian Mus. 1900-1.
St. Louis—Trans. Acad. of Sciences. Vol. 10, Nos. 9—11. Vol. 11,
Nos. 2—4. 1900.
St. John, Bull. Soc. Nat. Hist. New Brunswick. No. 19.
St. Petersbourg, Bull. Acad. Imp. Sci. Ser. 5, T. 12, Nos. 2—o5,;
T. 18, Nos. 1—3. 1900.
Toronto, Trans. Canadian Institute. No. 18. Vol. VII., Pt. 1. 1901.
Torino, Boll. Mus. Zool. Anat. Comp. Vol. XVI. Nos. 382-403. 1901.
Tokyo, Annotationes Zoological Japonenses. Vol. 3, Pts. 1—5. 1901.
LIBRARIAN S REPORT. XXVI.
Tokyo, Journ. Coll. Science Imp. Univ. Tokyo. Vol. 18, Pt. 4;
Volopeic. 2-5, 1901 Volo 16, Pt.; Vol. 17, Pt. 1, 1901.
Upsala—Nova Acta R. Soc. Sci. Vol. 19 (Ser. 3). 1901.
Upsala, Streptokockens och dess Toxins. Max. Bjorksten. 1900.
Upsala, Studier ofver ostersjons Hafsalgflora. Nils Svedelius. 1901.
Upsala, Beitrag zut Kenntniss der Spongienfauna des Malayischen
Archipels und der Chinesischen Meere. Nils Eustaf Lindgren. 1898.
Upsala, Otkast de grona algernas och Archegoniaternas Fylogeni.
Knut Bohlin. 1901.
Urbana (U.S.A.)—Bull. Illinois State Laby. Nat. Hist. Vol. 6,
NomdheOOi:
Venice, Catalogo Coll. d’Anat. Comp. R. Institute Veneto di Sci.
Lat. ed. Arti. 1900.
Washington, Proc. U. 8. Nat. Mus. Vols. 23—4 (in part). 1901.
Washington—Bull. U.S. Nat. Mus. No. 50. 1901.
Washington—Birds of N. and Mid. America. R. Ridgway. Pt. 1.
Fringillidee.
Wellington—Trans. and Proc. New Zealand Institute. Vol. 33. 1901.
Wien—Verhandl. K.K. Zool.—Bot. Ges. Bd. 51. 1901.
Wien—Ann. K.K. Naturh. Hofmuseums. Bd. 138, 14, 15, 16
(pts. 1—2). 1898-1901.
Zurich, Vierteljahrschr. Naturf. Ges. Jahrg. 45. Hefte 3—4;
Jahrg. 46, Hefte 1—2, 1901.
IJ.—List or Socrreties, &c., WITH WHICH PUBLICATICNS
ARE EXCHANGED.
(Additions made during the current session marked with an asterisk.)
AMmSTERDAM—Koninklijke Akadamie van Wetenschappen.
Koninklijke Zodlogisch Genootschap Natura Artis
Magistra.
BautImorE—Johns Hopkins University.
*BasEL—Naturforschende Gesellschaft.
BaraviA—Koninklijke Natuurkundig Vereeniging in Ned. Indie.
Brercen—Museum. ;
Beruin—Konigl, Akadémie der Wissenschaften.
Deutschen Fisherei-Vereins.
BirMincHAmM—Philosophical Society.
Botonesa—Accademia della Scienze.
Bonn—Naturhistorischer Verein des Preussichen Rheinlande und
Westfalens.
XXVI1i. LIVERPOOL BIOLOGICAL SOCIETY.
BorpEAux—Sociétée Linnéenne.
Boston—Society of Natural History.
BrusseLs—Académie Royal des Sciences, etc., de Belgique.
BuEnos ArrES—Museo Nacional.
Museo de la Plata.
CaEN—Société Linnéenne de Normandie.
CamBripGE —Morphological Laboratories.
CamMBRIDGE, Mass.—Museum of Comparative Zoology of Harvard
College.
Cuicaco, U.S.A.—The Field Columbian Museum.
The Botanical Gazette, Chicago University.
The Johns Hopkins University.
CHRISTIANIA —Videnskabs-Selskabet.
Dupiin—Royal Dublin Society.
EDINBURGH—Royal Society.
Royal Physical Society.
Royal College of Physicians.
Fishery Board for Scotland.
FRANKFURT—Senckenbergische Naturforschende Gesellschaft.
FrreIBURG—Naturforschende Gesellschaft.
GENEVE—Société de Physique et d’ Histoire Naturelle.
GiEssEN—Oberhessische Gesellschaft fiir Natur und Heilkunde.
GLAscow—Natural History Society.
GoTTInNGEN—Konigl. Gesellschaft der Wissenschaften.
Hatirax—Nova Scotian Institute of Natural Science.
Haute, A.S.—K. Leopoldinisch-Carolischen Akademie der Natur-
forscher.
HaarLeEmM—Musée Teyler.
Sociéte Hollandaise des Sciences.
HELIGOLAND Ko6nigliche Biologische Anstalt.
Inuinois, U.S.A.—Reports of the State Laboratory of Natural History.
KieL—Naturwissenschaftlichen Verein fur Schleswig— Holstein.
Kommission fur der Unterschung der Deutschen meere.
KyoBENHAVN—Naturhistorike Forening.
Danish Biological Station (C. G. John Petersen).
Kongelige Danske Videnskabernes Selskab.
Lawrence, U.S.A.—The Kansas University Quarterly.
Lrreps—Yorkshire Naturalists’ Union.
Lerpzia—Konigl. Sachs. Gesellschaft der Wissenschaften.
Linte—Revue Biologique du Nord de la France.
LivERPooL— Geological Society.
Bulletin of the Liverpool Museums.
LIBRARIAN'S REPORT. XX1X.
Lonpon—Royal Microscopical Society.
British Museum (Natural History Department).
MancuesterR—Microscopical Society.
Owens College.
MARSEILLES—Station Zoologique d’ Hndoume.
Musée d’ Historie Naturelle.
MassacuusEetrrs—Tufts College Library.
MrcKLENBURG— Verein der Freunde der Naturgeschichte.
MELBouURNE—Royal Society of Victoria.
Montevip—o—Museo Nacional de Montevideo.
Mon trreLuipr—Académie des Sciences et Lettres.
Moscou—Societé Impériale des Naturalistes.
MuncuHen —Allgemeine Fischerei-Zeitung.
*Ornithologischer verein.
Mitiport—Biological Station.
Nancy - Société des Sciences.
Naporti—Accademia delle Scienze Fisiche e Matematiche.
New Brounswick—Natural History Society.
Oporto —Annaes de Sciencias Naturaes.
Paris—Museum d’ Histoire Naturelle.
Société Zoologique de France.
Bulletin Scientifique de la France et de la Belgique.
Société de Biologie.
PHILADELPHIA—Academy of Natural Sciences.
PiymoutH—Marine Biological Association.
*“Roma—Societas Zoologica Italiana.
*RENNES—Bulletin Société Scientifique et Medicale.
Satem, U.S.A.—The Hssex Institute.
St. Louis, Miss.—Academy of Sciences.
Sr. PerERspuRG—Académie Impériale des Sciences.
San FRancisco—California Academy of Science.
SANTIAGO—Société Scientifique du Chili.
STAVANGER—Stavanger Museum.
StockHoLtmM—<Académie Royale des Sciences.
Sypngey—Australian Museum.
Tox1o—Imperial University.
Zoological Society of Tokyo.
- Torino—Musei de Zoologia ed Anatomia Comparata della R. Universita.
Toronto—Canadian Institute.
TRIESTE—Societa Adriatica de Scienze Naturali.
UpsaLta—Upsala Universitiet.
Société Royale des Sciences,
XXX. LIVERPOOL BIOLOGICAL SOCIETY.
Ursana, U.S.A.—Bulletin of the Illinois State Laboratory of Natural
History.
WAsHINGTON—Smithsonian Institution.
United States National Museum.
United States Commission of Fish and Fisheries.
Wexuineton, N. Z.—New Zealand Institute.
Wien—K. K. Naturhistorischen Hofmuseums.
K. K. Zoologisch—Botanischen Gesellschaft.
*ZAGREB—Societas Historica—Naturalis Croatica.
ZuricH—Zurcher Naturforschende Gesellschaft.
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TRANSACTIONS
-00L BIOL
INAUGURAL ADDRESS
ON
THE FAUNA INDICATED IN THE LOWER KEUPER
SANDSTONE OF THE NEIGHBOURHOOD
OF LIVERPOOL.
By H. C. BEASLEY, Presipent.
[Read 11th October, 1901.]
I think no excuse is needed for the subject of my
address being rather an unusual one in our Society,
although it may even seem to some to be outside the
limits of our science. I can only say that to attempt the
study of Biology without Paleontology, and some know-
ledge of Geology, could only be paralleled by an attempt
to study man, to govern him or to legislate for him, with-
out some knowledge of history and geography. I would
therefore ask you to carry your thoughts back to a time
when the portion of our Harth’s surface now occupied by
South Lancashire and Cheshire was a comparatively
barren waste, the material of its surface continually kept
in motion by the wind, and occasionally by heavy rains,
temporary torrents and probably some more permanent
streams constantly changing their position, and affected by
the same conditions that to a greater or less extent still
prevail in the central portions of our continents—condi-
tions very ill calculated to preserve any organic remains,
but which have produced the beds of sandstone and con-
4 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
glomerate known as the Lower Keuper Sandstone so largely
developed in our neighbourhood, particularly on the
Cheshire side of the Mersey, and supplying the greater
part of our building stone.
These immediately underlie the beds formed by
aqueous sedimentation in inland lakes, and known as the
Upper Keuper Marls, in which the well-known salt deposits
occur ; ‘below them lie the Bunter Sandstones. The Lower
Keuper and the Bunter together form an alternating series
of hard and soft sandstones, of which the Lower Keuper
is the highest member. There is, however, reason to suppose
that some time elapsed, and some change of conditions took
place between the deposition of the uppermost beds of the
Bunter and those at the base of the Keuper; at any rate in
this district the conditions altered to the extent of preserv-
ing certain traces of life in the Keuper and of retaining none
in the Bunter. At this period the old fauna of the Paleozoic
rocks had disappeared, and the new forms which charac-
terise the Mesozoic period were coming to light. The
vertebrate type of skeleton had thoroughly established
itself, and in the course of development had reached the
parting of the ways. The principal forms were represen-
tative of the lower reptilia, but those differentiations were
already well marked which were to give rise to the lizards,
birds and mammals as we now have them; indeed, it is
possible that lower mammalia had already been evolved,
though perhaps not present in this part of the world till
later. The birds are more doubtful. We have many
peculiarly avian characters present in some of the reptilia,
but of anything hke a Triassic bird we have no record in
this country, and their course of evolution is very uncer-
tain. The Trias, therefore, represents a period particu-
larly interesting to the Biologist, and a complete know-
ledge of its fauna would solve many questions that now
a
FAUNA—-LOWER KEUPER SANDSTONE. 5
perplex us. Such a complete knowledge we can, however,
hardly expect to attain; but we may reasonably hope in
the near future to add largely to the knowledge we possess.
The thousands of feet of Shales, Marls and Sand-
stones, probably approaching a mile in thickness, that
intervene in this country between the coal measures, teem-
ing with life at the close of the Paleeozoic period, and the
Lias full of the remains of the life of the Mesozoic, are as
a whole remarkable for their dearth of fossils, whilst the
Bunter Sandstone (about the centre of the series) so
largely developed in this neighbourhood is absolutely non-
fossiliferous, though the pebbles enclosed in it contain
remains of a much earlier geological period, and the
Keuper above it yields us only very uncertain traces. It is
with these slight traces that I propose to deal this evening.
They consist of the footprints of vertebrates and the tracks
of some invertebrates. A few other districts are, however,
more fortunate, and in limited areas in our own country
sufficient remains have been found to show that a
numerous and varied fauna existed, whilst allied, if not
actually similar, forms have been found in comparative
abundance in the Trias of South Africa, India, Australia
and the continent of Hurope, and in North America.
Within the last year the announcement has been
made of the discovery of a rich deposit of well-preserved
vertebrate remains in the valley of the Dneiper, in strata
of probably the same age, although spoken of as Permian,
including examples of the same genera that are found in
the similar deposits in South Africa and India, from which
hitherto the greater part of our knowledge of the land
animals has been derived; and it is to be hoped that
shortly more detailed descriptions of the forms found will
be published.
According to the catalogue of British Fossil Verte-
6 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
brata (Woodward & Sherborn, issued i there were
known to the British Trias—
Fishes, 6 genera;
Amphibia, 5 genera;
Reptilia, 9 genera.
Since 1890, however, the numbers have been greatly in-
creased, mainly by the labour of Mr. E. T. Newton,
F.R.S., upon material collected from the sandstones of
Elgin, whence the bulk of our British Triassic vertebrate
have hitherto been obtained.
As might have been expected from the nature of the
deposit, our district has yielded no trace of FrisHEs, though
they have been found in beds of the same age near
Nottingham, and a single specimen of Dipteronotus at
Bromsgrove, Worcestershire.
Turning next to the Ampursia, the earliest known
four-footed air-breathing land animals were the Stego-
cephala or Labyrinthodonts. The head was completely
roofed in by bones, was connected with the vertebral
column by either 2 occipital condyles, or none, the limbs
were of pentadactyloid type, and the vertebral column
comprised a well-developed and often long tail. We see
in them a distinct step in the evolution of the vertebrates
from the aquatic to the land type. They had not arrived
at the dignity of reptilia; they are known to have been
amphibia, and only air breathers in their adult condition.
They seem to have been at their prime as to numbers and
variety in Carboniferous and Permian times, but were
giving way to higher forms in Triassic times.
It was, until a few years ago, very confidently stated
that the well-known hand-shaped footprints found at
Storeton were those of the Labyrinthodon. This seems
first to have been suggested by Sir R. Owen many years
ago; but since then, as more material became available,
2
FAUNA—-LOWER KEUPER SANDSTONE. if
the Labyrinthodontia have been thoroughly worked out,
and our faith in the Labyrinthodont origin of the foot-
print is somewhat shaken. The footprints were originally
attributed to an unknown animal designated the Cheiro-
thereum. At the suggestion of the late Mr. G. H. Morton,
F.G.S., the specific designation storetonense was added
to distinguish the more common Storeton form.
This footprint, as found at Storeton, has roughly the
form of the human hand, and varies in length from 54
inches to 9 inches. The smaller ones are as a rule very
much alike, but the largest ones, which, however, are not
at all common, have more fleshy digits, with the nail not
so distinctly shown. ‘There are 5 digits of about the same
proportions as those of the human hand: four slightly
divergent; one—an outer one, greatly resembling the
human thumb—is more divergent, curved laterally and
posteriorly, but there is every reason to believe that it is
the fifth digit.
The integument of the sole of the hind foot is divided
by constrictions into divisions forming pads, which may
perhaps be considered to indicate the joints and phalanges
of the digits, and all the digits are terminated by sharp,
strong claws. Owing to the imperfections of all the im-
pressions, it is not an easy task to determine the actual
number of phalanges on each digit.
The result of my examination of a great number of
prints is in favour of 5 phalanges each to the three inner
digits and 2 for the two outer, but as there is scarcely ever
any marked constriction on the curved digit, the number of
its phalanges is doubtful.
At the base of each digit is another pad of the same
character as those just described. They appear to cover
the distal extremities of the metatarsals, the only portion
of the metatarsals reaching the ground. There is a
8 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
tendency as age increases for two or more of these pads
to coalesce. That at the base of the curved digit is larger
than the rest, and serves to form the hinder and outer
margin of the foot. On the other side there is generally
no impression at all in the rear of the pads of the other
digits. The function of the curved digit is not clear.
That it was opposable is extremely doubtful; it is always
found in the position shown in the specimens before you
(Fig. 1, plate II.), and probably merely took some small
share in the support of the body. In front of this hind
foot, as we may suppose it to be, at a distance of a few
inches, and in the same line, is usually found the print of
a much smaller foot, which we may safely take to be the
fore foot. It has five short, stout, tapering and rather
widely divergent digits, the one corresponding with the
curved digit of the hind foot being most divergent, in
some cases pointing rather backwards than forwards.
There are hardly any traces of divisions of the phalanges,
nor are there of terminal claws. The footprint is rather
broader than long, and is generally somewhat less than
half the length of the hind foot.
The print of the fore foot is generally less distinctly
marked than that of the hind foot. If we take a series of .
feet, they are found to be all nearly in a straight line; the
axes of the right and left tracks are not more than about
din. apart, often much less, whilst the stride, measured
from the tip of the toes on one foot to those of the next -
_ impression of the same foot, is between 3ft. 6in. and 4ft.
The soles of both hind and fore feet were covered with
small protuberances. This appearance was first described
by Professor W. C. Williamson as being observed on a
footprint from Daresbury, Cheshire,* and he points out
* Quart. Jl. Geol. Socy., vol. xxlii., p. 56. 1867.
a. se ee Oe ee le
FAUNA—-LOWER KEUPER SANDSTONE. 9
that the arrangement of the scales corresponds very closely
with that seen in the foot of the living alligator, “ and
“many of them run across the foot in oblique lines, as is
“common among living crocodiles, leaving no doubt that
“they represent the scales and not irregular tubercles
“such as are seen in the skin of the Batrachians.”’ He
concludes “it is saurian if not crododilian in every
“feature.” The figure shows a form resembling the fore
foot of the Cheirotherium, though only four toes are
shown there is a trace of there having been a fifth.
During the past summer a number of good footprints
have been obtained at Storeton from the second footprint
bed from the top, and almost every one of them shows
these scales. I was fortunately able to examine the foot
of a young living crocodile in the free museum, and can
confirm Professor Williamson's remarks.
Now are these the tracks of the Labyrinthodon? The
idea originated when the only bones found in the Keuper
indicating an animal of such a size as might be supposed
to coincide with that of the footprints, were those of the
Labyrinthodon. ‘This, as we know after the discovery of
material unavailable to earlier workers, was improbable.
Professor Miall, in his report* on the Labyrinthodonts
to the British Association, showed this most clearly; and
the statement of Hans Gadow in his recent work on the
Amphibia and Reptilia (page 83) seems to decide the
matter. He says—‘‘'The spoors of Cheirotherium common
“in the Red Sandstone of Germany and England, for
“instance in Cheshire, belong to unknown owners; both
“the large hind feet (which measure nearly half a foot in
“length) and the much smaller fore feet had five digits,
“the first of which stood off like a thumb. /Fvve-fingered
“ Stegocephalt are unknown.”
* Brit, Assoc, Reports, 1873, p. 243.
10 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
A five-toed animal frequently makes a print in which
but four toes are recognisable, but the circumstances
under which a four-toed foot could make an additional
print of one toe would be very exceptional and would be
readily detected. ?
Another point may be noticed. The Labyrinthodon
was a tailed Amphibian. In a few experiments I have
made with the common water newt and the European
Salamander, they always left a track made by their tails
when walking over a soft surface. No such tail is asso-
ciated, as far as I have seen, with these footprints. The
impression of something that may have been a tail of an
animal is to be seen on a slab in the British Museum,
which is reproduced in Mr. Morton’s Geology of
Liverpool.* Rather smaller but similar markings are
also shown on a slab at Warwick. The British Museum
example shows distinctly rows of scales, and if the impres-
sion of a tail, it must have been made when the animal
was stationary. It is uncertain, however, at present
whether these are of animal or vegetable origin.
If, then, the footprints known as Cheirotherium are
not Labyrinthont, where are these of the Labyrinthodon ?
I cannot answer the question, but I do not see that it
affects the case very much. At the same time I feel an
amount of disappomtment that such an interesting group
of animals should not have left any distinct evidence of
their presence here.
There is plenty of room both for research and specu-
lation here, as it is hardly likely that the Amphibia were
absent altogether; but the brilliant imaginations of more
than one artist and writer have failed to fill the gap
satisfactorily. We have a few small, broad, fleshy foot-
* Appendix, p. 300,”plate xxii.
FAUNA—-LOWER KEUPER SANDSTONE. se
prints that may possibly have been Amphibia, but we have
no proof whatever of it.
Reptizia.—We will try for a moment to find some
more stable ground, and consider a form of which we have
both the bones of the foot and a print to match.
We are no longer dealing with the Amphibia, but
with true reptiles. Rhynchosaurus articeps was described
by Owen in 1842,* from remains found im the
quarries in the Lower Keuper Sandstone at Grinshill
in Shropshire. The sandstones in this quarry are a con-
tinuation in that direction of the beds at Storeton and
elsewhere in our district. In the same quarry numerous
footprints were found, and Owen, although he had none
of the bones of the extremities before him, suggested the
probability that the remains were those of the animal that
made the footprint. I was disappointed to find, however,
that the footprints referred to were not figured in his
paper nor described in detail, nor have I been able to find
any slab that can be identified as the one having been
seen by Owen, if in fact he did see them himself; he only
quotes in his paper some correspondence with Dr. Ogier
Ward, of Shrewsbury. Dr. Ward says—“ As they (the
“remains) have always been found nearly in the same
“beds as that impressed by the footsteps I have described,
“T am induced to believe they are the bones of the same
“animal.” Owen adds—* And in this opinion, from the
“correspondence of size between the bones and the foot-
“ prints, and from the circumstance of the absence of other
“observed bones or footprints in the same quarry, I
“entirely coincide.” Farther on, after describing some
fragments of the pectoral arch, he says—‘‘ They indubit-
“ably indicate a mechanism for locomotion on land which
*Trans. Camb. Philosophical Society, vol. vii., p. 155, 1842,
12 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
“would agree with that of the animal which has left
“impressions in the sandstone.”
Although several kinds of footprints have been
noticed in the Grinshill quarry, there is one form which is
far more common than the rest, and is no doubt the one
alluded to by Owen. Since that time much more material
has been discovered; and Huxley has described and
figured further specimens in Q.J.G.S., vol. 48, p. 689,
where the extremities are well shown, and they are found
to entirely confirm Owen’s suggestion. Numerous other
finds have been made at Grinshill (and a few elsewhere),
and as these footprints are also among the most common
‘ones found here, I think we may without hesitation take
it as a fact that Rhynchosaurus was present here im
Lower Keuper times.
The Rhynchosaurus, besides being interesting to us
as having belonged to the local fauna, has much wider
interest from the position of the Rhvnchocephalide in the
zoological series; and the fact that a representative of the
family still survives in Sphenodon punctata in some of the
small islands off the coast of New Zealand. This not only
gives some hints as to the probable habits of Rhyncho-
saurus, but also very materially assists in dealing with
the imperfections that occur in almost all fossil remains.
Although very lizard-like in outward form, the Rhyncho-
cephalide, including Sphenodon and MHyperodapedon
differ greatly from the lizards both in their bony structure
and the anatomy of their soft parts.
They are linked through Paleohatteria, which made
its appearance in Permian times, with the Amphibians,
but are truly reptilian and possess a single occipital .
condyle. As the name implies, they were provided with
a horny beak, but were not edentulus, Rhynchosaurus
having a row of acrodont teeth anchylosed to the palate,
FAUNA—LOWER KEUPER SANDSTONE. is
another to the inner side of the maxilla, and a row on the
mandible fittmg into a hollow between. These crushing
teeth are, however, supplemented by the horny covering
of the maxilla and mandible. The premaxille are pro-
longed into a pointed and recurved beak, which was also
encased by a horny sheath. The skull is short, broad and
somewhat pyramidal in form. The species described and
figured was probably two to three feet in total length, and
the feet are considerably larger than many of the prints
usually attributed to it. There are, however, many of the
full size of Huxley’s figure, and the smaller ones present
exactly the same features, the principal one being that
the fourth digit is the longest, and this cannot too strongly
be borne in mind when investigating the footprints.
Unfortunately the prints are usually imperfect, and at
times it is difficult to allot the correct numbers to the
digits shown.
The hind feet, you will notice; are the most perfectly
preserved; the fore foot, or manus, is not so good, but I
have here the photograph of a fore mb in the Shrews-
bury Museum (Plate I., Fig. 2). The hind limb of the
same not having been preserved, it is impossible to state
the proportion in size between the pes and the manus.
The footprints are so intricately mixed on all the
surfaces recording them that it is not possible to trace—
or rather, I should say I have not succeeded in tracing—
any continuous track, or positively determining the fore
and hind feet of the same animal. This is readily ex-
plained if the Rhynchosaurus was like the Sphenodon in
its habits, for on the only occasion on which I have had an
opportunity of observing the latter, where they had room
to move freely, they were intensely active without any
apparent object, darting about in all directions, and it
- would have been a difficult matter to trace the tracks of
14 - TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
any individual set of feet, thus presenting a marked contrast
to the stately march of our unknown friend the Cheiro-
therium. Although we have a pretty clear idea of the
footprint of the Rhynchosaurus, a number of the prints
merely attributed to it from their size and lizard-lke
appearance, probably were made by other animals.
Although undoubtedly it was a tailed animal, we have no
distinct traces of the tail of the Rhynchosaurus.
_ Another member of the family whose remains are
perhaps more generally distributed in Great Britain 1s
Hyperodapedon. Fairly perfect remains have been found
at Elgin, and more fragmentary at Warwick and South
Devon. We are indebted to Professor Huxley for a full
description and figures (Q.J.G:S., vol. 43, p. 675, 1887).
Through the kindness of Professor Herdman I have here a
cast of the skull, which will give some idea of the struc-
ture of the skulls of the Rhynchosauride. Hypero-
dapedon was somewhat similar to Rhynchosaurus, but
instead of two rows of teeth it had several, the roof of the
mouth being nearly covered. It was a much larger
animal, being six or seven feet long, and in many respects
was more specialised. |
Unfortunately we have no remains of the posterior
extremity, but the whole of the fore limb we have fairly
perfect. The manus seems to have been rather smaller
in proportion to the size of the body with rather stouter
digits, and was probably more expanded than that of the
Rhynchosaurus.
Judging from its somewhat wide distribution, we
have some grounds for expecting its presence here, but its
footprints have not been identified.
The Telerpeton, another allied genus, was much
smaller, not exceeding a foot in length, and resembles the
true lizards more nearly than the forms just described.
FAUNA—-LOWER KEUPER SANDSTONE. 15
Only two examples have been found, and these, though
fairly perfect in other respects, want the extremities of the
fore and hind limbs, so we have no means of recognising
their footprints. The Rhynchosauride were very
generalised reptiles, Hyperodapedon being the most
specialised ; Sphenodon the least so, and probably for that
reason this form has survived and illustrates from another
point of view the remarks made by Professor Herdman
some time ago on the effect of high specialisation on the
Ammonites.*
We will next consider the ANomoponrTI1A, essentially
a Permian and Triassic group, interesting from their being
directly intermediate in their skeletal characters between
the highest Labyrinthodontia and the lowest Mammals.
They are best known to us by examples from South Africa
and India, described by Owen, Seeley and others; they
are also represented in Great Britain by several forms
allied to Dicynodon, found at Elgin, and finely worked
out and described and figured by Mr. H. T. Newton,
E.R.S.,+ who has included them in two new genera,
Gordonia and Geikia, named after that well-known
geologist, Rev. Dr. George Gordon, to whom we are
mainly indebted in the first instance for the Hlgin fossils ;
and Sir A. Geikie, F.R.S., Director-General of the
Geological Survey. The principal bones known are those
of the skull, a striking feature of which is the great lateral
expansion of some of the bones, giving the head the
appearance of being much larger than it really is. The
brain space is remarkably small. The parietal crests
extend down the posterior portion of the skull, and passing
forwards form the temporal arch.
There is a feature in Gordonia Traquari which will
* Proc. Liverpool Geol. Soc., President’s Address, vol. ix., p. 6.
+ Some New Reptiles from the Elgin Sandstones, by EK. T. Newton,
F.G.8., F.R.8., Phil. Trans. Royal Soc., vol. 184 (1893), B., p. 431.
16 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
interest those who remember Dr. Hanitsch’s researches
regarding the pineal eye. Mr. Newton writes, describing
the skull of Gordonia Traquari—‘‘ Between the anterior
“part of the parietal crests is the large pineal fossa which,
“as can be seen in the right half of the skull, forms a very
“distinet cup opening below into the brain cavity. The
“deep cup-like form of the pineal fossa is probably an
“indication that 1t lodged a well-developed eye.” The
Labyrinthodons have a well-marked pineal fossa; the
pineal eye is present in Sphenodon, but it has not been
detected in Hyperodapedon.
Of the form of the limbs something is known, though
not of the extremities. Ido not know whether I am right
in my conjecture, but I should suppose that the broad
humerus would very likely be accompanied by a short-toed
broad foot.
Another very remarkable form has been figured from
Elgin, to which Mr. Newton has given the name Elginia
Mirabilis ; * this he considers is more allied to Pareiosaurus
than to Dicynodon. Of none of the species of Gordonia,
nor of Elginia, have the bones of the feet been preserved,
and to form an idea of the foot we must refer to their
South African relations. The national collection con-
tains a nearly complete skeleton, finely mounted, of
Pareiosaurus bombidens described by Professor Seeley,
and the short broad feet are clearly shown; and it is quite
possible that a rather common form of footprint here may
represent an allied animal. The Dicynodon remains at
Elgin would represent an animal about the size of a terrier
dog. Some years ago I had the honour of reading to this
Society a short papert on a small footprint with short toes
bearing strong claws which has been frequently found at
*
* Loc. cit., p. 473.
+ Trans. Liverpool Biological Soc., vol. xi, p. 179.
FAUNA—LOWER KEUPER SANDSTONE. 17
Weston quarries and occasionally at Storeton. Professor
Seeley considered that it bore much resemblance to a
South African form (Keirognathus). The size of the foot
would about suit such an animal as Gordonia Traquairi.
These footprints have always been attributed to
Chelonia since they were first observed, but we have no
record of remains of Triassic Tortoises or Turtles having
been found in this country, and though negative evidence
is of little value, I think it would be safer to assign these
to an Anomodont than a Chelonian. I may just note in
passing that the small oval mark with marks of the claws
figured in Morton’s Geol. Liv., and called by Professor
Ant, Fritsch Saurichnites perlatus, and comparatively
common here, is remarkably lke the footprint of a
Terrapin, but there are intermediate forms that tend to
connect it with the one supposed to be the footprint of an
Anomodont.
Drinosavria. Though the Dinosaurs flourished in the
later part of the Mesozoic period, we find traces of them
in the Keuper in the neighbourhood of Bristol. With
their general form you are doubtless familiar. There is
a great discrepancy in the size of the fore and hind hmbs.
This discrepancy is also said to be shared by some of the
earlier forms of the Crocodilia, but it is so great in some
Dinosaurs that there is every probability that they walked
on their hind legs, and as they reached, if not exceeded,
the size of our largest Mammals, they must have presented
a somewhat formidable appearance. The supposed bipedal
forms were probably carnivorous, the quadrupedal herbi-
vorous. Many most startling restorations have been made,
but it seems to me that any of us with the skeleton before
us can bring before our minds a sufficient picture of its
general form.
It has been thought that we have here a forerunner
B
18 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
of our birds, and certainly there are many points of
resemblance between them and the Ratite; but I believe
the general opinion now is that they were not in the direct
line of descent.
Professor Miall, in his repert on the Labyrintho-
dontia,* suggests that our Cheirotherium footprints are
more Dinosaurian than Labyrinthodont, and it may be
useful to us if we go into this question. I may at once
admit we have nothing in our Sandstones that we can say
is certainly a Dinosaurian footprint. A point that has
occurred to me is that the Storeton footprints are more
digitigrade than we have hitherto imagined, though the
foot was occasionally put down so that the whole length of
the metatarsals came in contact with the ground; at
least, I think this was the case with the well-known print
called Cheirotherium hereulis (Plate I., Fig. 1).
The digitigrade character is shown well in a slab
in the Owens College Museum, believed to have come from —
Storeton (Plate IIL, Fig. 1). The Dinosaurs of the
Wealden had 3 functional toes and have left us their foot-
prints, but with the Triassic forms we are not well
acquainted, and caution is requisite in working on
Professor Miall’s hint.
The dolomitic conglomerate of Durdham Down,
Clifton, in which were found the remains of two genera of
Dinosauria, the Paleosaurus and the Thecodontosaurus, is
also exposed along the northern shore of the Bristol
Channel, and near Newton Nottage, Glamorganshire, Mr.
Sollas has noticed and described ta series of three-toed
footprints: the toes are divergent and the footprint as a
whole is entirely different from our Storeton prints. It
will be noticed, however, that the individual digits are
* Brit. Assoc. Reports, 1873.
+ Quart. Jour. Geol. Soc., vol. xxxy., p. 511.
FAUNA—-LOWER KEUPER SANDSTONE. 19
something similar in form to ours. (See Plate II., Figs.
1 and 2.) Now if we refer to the Storeton print and
imagine the outer digits becoming functionless and
aborted, the three inner ones would consequently probably
become more divergent, and we should have a footprint
somewhat of the character of the Newton Nottage ones.
The dolomitic conglomerate is supposed to be rather
higher in the series than the Storeton footprint bed. The
authorities of the Cardiff Museum have kindly had taken
- for me a photograph of the Newton Nottage footprint, of
which Plate II., fig. 2 is a reproduction.
Several years ago the Rev. P. B. Brodie pointed out
to me in his own collection, and in that of the Warwick
Museum, several instances of impressions in slabs bearing
the Cheirotherium footprints of what he believed to be
the hind quarters of the animal, as if it had squatted down
on the ground. At that time it was generally considered
that the Labyrinthodont origin of the footprints was quite
settled. An animal with a short thick tail could hardly
have done this, and I was rather inclined to think that the
markings might have been made by the anterior portion
of the under surface of the body, as I noticed that Sala-
manders and Newts often stopped suddenly and rested
the front portion of the body at once on the ground.
However, in his “ Outlines of Vertebrate Paleontology,”
Dr. Arthur Smith Woodward, when describing the Dino-
saurian skeleton (page 198), and speaking of the extension
of the pubes and the ischia, says—‘ The symphysis is in
“both cases much extended, evidently to serve as a kind
“of ‘foot’ when the animal rested on its hind quarters. |
“Certain impressions in the Triassic Sandstones of Con-
“necticut suggest this idea.” He was evidently unaware
of similar impressions nearer home. It certainly would
render a sitting’ posture much more easy for an animal
20) TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
encumbered with a massive tail than it would have other-
wise been.
Without further evidence it would be most unwise to
assert that the Storeton footprint represents the presence
of a Dinosaur, but I think I have shown the possibility of
such having been the case. On the other hand there also
remains the possibility of the footprint having been made
by one of those animals of whom we have no knowledge
whatever, but which nevertheless we firmly believe at one
time, probably during the period we are considering, to
have existed, and to have formed the connecting links
between the Amphibia and the Mammalia.
In the Ann. & Mag. Nat. Hist., 2 Sees., vol. 6, 1853,
Professor R. Harkness described several footprints from
Weston Point, Cheshire. Most of them I have recognised
there, but one form I have failed to satisfactorily identify.
He says—“ Amongst these there occur impressions of a
“'Tridactylous character, and the position these assume
“are such as to indicate that they bear relation to the
“footprints of bipedal animals. Length of print, 2 inch;
“length of stride, 7 inches; 3 well-developed toes, centre
“one twice the size of the other toes; and the general
“ appearance of the impressions has a great similitude to
“the Ornithichnites diversus of Hitchcock.” These
American footprints are now considered Dinosaurian.
Fifty years ago the Dinosaur was a greater stranger than
at present, and it will be worth bearing Professor Hark-
ness’s observation in mind when considering the traces of
Dinosaurs in our district. As I have said, I have so far
been unable to confirm Professor Harkness, but I hope to
do so before long. Weston Quarries are a grand store-
house of footprints, and I seldom go there without finding
something new to me.
Crocopit1a. “It is as yet impossible,” says Dr. A.
FAUNA—-LOWER KEUPER SANDSTONE. a1
Smith Woodward, “to distinguish the Triassic ancestors
“of the Crocodilia from those of the Rhyncocephalia and
“Dinosauria.”* Of Stagonolepis, the subject of Huxley’s
well-known paper,t the extremities are too little known
to warrant our speculating on its presence here. Mr. E.
T. Newton, F.R.S., has described an allied genus, Erpeto-
suchus,{ from Hlgin, and though the extremities are pre-
sent they are so imperfectly preserved that it would be
unwise to try to match them with any of our footprints ;
the few and weakly marked bones of the digit we have
may have been so covered with flesh as to give the foot a
form more or less differing from that of the bony
skeleton.
Another form also described by Mr. Newton in the
same paper, “Ornithosuchus woodwardii,” presents so
many points of resemblance to both the Parasuchia and
the Dinosauria that it is evidently with great hesitation
that he at last places it provisionally with the latter. The
bones of the left hind foot, though not in position, are all
well preserved, so that it may be possible to restore the
foot and search for its impression. The remains which
are the subject of the paper, and also of the Dicynodonts,
&c., referred to earlier, are all in the Geological Survey
Museum, Jermyn Street, London, and I must express my
thanks to Mr. Newton for the ready assistance he has so
kindly rendered me whenever I have referred to him.
In his paper on Stagonolepis and the Evolution of
the Crocodilia,§ Professor Huxley in 1875 remarked on
* Outlines of Vertebrate Paleontology, p. 216 (1898).
+ Quart. Jour. Geological Socy., vol. xxxi., p. 423.
t Reptiles from the Elgin Sandstone, description of two New Genera.
Phil. Trans. Royal Soc., vol. 185 B., p. 574 (1894).
§ Quart. Jour., Geological Socy., vol. xxxi., p. 424.
92, TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
the very poor fauna indicated by the fossil remains of the
Elgin Trias, whilst their evidently carnivorous habit
would require abundant food. Since he wrote that his
evident expectation has been fulfilled, and the remains of
a more abundant, though still restricted fauna have been
found; but that we at present know of anything beyond a
very small proportion of the Triassic fauna is very un-
likely. The more we examine the footprints in our local
Sandstones, the more certain we are that they represent a
far more varied fauna than was supposed. At one time
local geologists were content to name all the larger ones
Cheirotherium and the smaller Rhynchosaurus. The late
Mr. Morton considered* that only six species were repre-
sented. Since then (1897) so many other forms have been
noted that even after making due allowance for imperfect
impressions, and differences between fore and hind feet,
there still remains evidence of a fauna quite varied enough
to furnish the food supply required by Professor Huxley’s
reptilian carnivora. Of the flora which must form the
basis of any food supply we know very little beyond the
natural casts of a few equisetiform plants. We have
traces of a more plentiful flora in the Upper Keuper, and it
is quite possible that Upper Keuper conditions may have
prevailed at no great distance outside our area at the time
our Lower Keuper Sandstone was being formed. The
consideration of this very interesting point would, how-
ever, lead us beyond the limits of this address.
_ We have numerous traces of the presence of inverte-
brata. Some we may safely attribute to worms or
Gasteropods, others, consisting of sinuous double rows of
minute pittings, closely resemble those made by minute
crabs; but the tracks of invertebrates are even more un-
certain than those of vertebrates. :
* Geology of the Country around Liverpool. Appendix page 299.
FAUNA——-LOWER KEUPER SANDSTONE. 23
There is in the Woodwardian Museum at Cambridge
a slab with a winding track about ~ of an inch wide,
which { presume is referred to in the following extract
from the catalogue :—‘‘ There are 5 slabs also arranged on
“the Hast side of the compartment showing footprints of
“various reptiles, of a Crustacean, and rain prints and
“sun-cracks from the N.S.R. of Cheshire.” I was quite
inclined to agree with the catalogue as to its Crustacean
origin when I saw it, but within the last month I have
seen similar tracks on the Leasowe shore and have doubts
as to their Crustacean origin. In several instances there
was at the end of the track a small hole going down verti-
eally into the sand, but on digging down I failed to detect
the presence of anything that could have made the track ;
further investigation will be made.
The results of our investigations may be briefly
summarised thus :—
I.—We have seen that we have no actual evidence of
the presence of the Labyrinthodontia.
I1.—That certain footprints very commonly found
here are almost certainly those of Rhynchosaurus and
allied forms.
I1J.—That as regards the Anomodontia we are not so
sure but that some short broad footprints are probably
due to reptiles belonging to this order.
1V.—That with regard to Dinosauria we are quite in
the dark; unless the Storeton footprints or Harkness’
tridactylate prints at Weston should eventually be found
to belong to them, we have nothing that seems likely to
fit them. i
V.—And of the early ancestors of the Crocodilia we
have so far seen no traces in our district.
VI.—Of Fishes, no traces.
VII.—Of the invertebrata, Vermes and probably
24 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
Mollusca have left decided traces, as have also other inver-
tebrates unidentified.
We must remember that there are numbers of foot-
prints different from any I have so far described or classi-
fied. The great proportion of these are of small size,
varying from in. to an inch in length. From the nature
of the traces of fossil remains so far discovered in the Trias
in this country, it is highly improbable that we shall find
remains of animals small enough to fit these prints. The
smallest hitherto found is the Telerpeton elginense,
measuring a foot in length; it is included in the Rhyncho-
cephalia; only two specimens have been seen, and in those
the bones of the feet were missing. There may be some
among the smaller prints due to these, but it is impossible
to say which until we are able to compare them with
remains that we may hope will be found elsewhere, where
the conditions were more favourable to their preservation.
The Paleontology of the Trias is perhaps more
interesting, and its study is likely to lead to more impor-
tant results than that of any other geological period. The
expedition to Greece this spring has enabled Dr. A. S.
Woodward to bring back to the British Museum a great
amount of material which there is every hope will enable
us to follow the later stages in the evolution of the higher
vertebrata with far more certainty than has hitherto been
the case. The earlier and more important stages, which
took place probably during the period we have been look-
ing into to-night, are comparatively unknown. Let the
members of this Society bear this in mind when in search
of a field in which to expend their energies.
Rather more scope is, I believe, allowed in a presi-
dential address to the exercise of the imagination than
would be permissible in a more technical paper. I fear,
however, that I may have exceeded that liberal allowance.
. FAUNA—-LOWER KEUPER SANDSTONE. 25
If my suggestions and suppositions have been, as I iear
they have, out of all proportion to actual fact, I must.
plead as an excuse the very small amount of fact available,
and I can only ask the members of this Society to help te
supply the deficiency.
—
26
Fig.
Fig.
Fig.
Fig.
TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
EXPLANATION OF PLATES.
Puate I,
1.-Natural casts of footprints of Chewrotherrum
herculis in Brit. Mus. Nat. History. See Proc.
Liv. Geol. Soe., vol. ix., plate v.
2. Fore limb, W&e., of Rhynchosaurus from the
Keuper Sandstone of Grinshill, Salop, from a
photograph taken, with the kind permission
of the Shrewsbury Museum Committee, by
Mr. Forest, of Shrewsbury.
Puate II.
1. Slab of Sandstone, probably from Storeton, with
natural casts of two series of footprints in
Owens College Museum, from a photograph
taken by permission by Mr. Ward, of Man-
chester. aandc,right pes; b, left pes; between
a and b the print of the right manus is shewn.
d, ce, f belong to another series.
2. Footprints from the Keuper of Newton Nottage,
Glam., now in the Cardiff Museum. A 2-foot
rule is shown against the slab. The length of
the middle digit is nearly equal to that of the
impression of the whole pes on Fig. 1. (1am
indebted to the courtesy of the Authorities of
the Cardiff Museum for the photograph from
which this is taken.)
Prats I.
. =
¥,
. cry
{
=!
/
y)
4
ad ’
7 !
Me
~
:
;
Li,
bs
Prats II.
Fig. 2.
=
ee
27
FIFTEENTH ANNUAL REPORT
OF THE
LIVERPOOL MARINE BIOLOGY COMMITTEE
AND THEIR
BIOLOGICAL STATION at PORT ERIN.
By Professor W. A. Herpman, D.Sc., F.R.S.
Tne most important event that falls to be recorded this
year is the arrangement concluded with the Government
of the Isle of Man, as a result of which we shall in future
occupy increased Laboratory accommodation and_ be
responsible conjointly with a committee of the Tynwald
Court for the conduct of a large Aquarium and Fish
Hatchery. A detailed statement as to how this change
has been brought about, as to the position of our’ Com-
mittee in relation to the Manx Government and as to the
probable effect upon our work will be given below. But
it must be obvious to all that as this implies a removal
from our present Biological Station to larger and more
convenient buildings on a better site at the other side of
the bay, it is clearly the most important event in the
history of the L.M.B.C. since we first established our
laboratory at Port Erin. This then is the last Annual
Report which will deal with the present Biological
Station. Next year’s Report will have to do with a much
larger concern, in which more attention will be given to
fisheries investigations and economic work than has been
possible in the past. We have now had a Biological
Station in working order for fifteen years. The first five
28 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
Annual Reports recorded the work at the Puffin Island
Station, and the next series of ten (ending with the
present Report) dealt with the first Port Erin Laboratory.
It is hoped that next year’s Report, the first of a new
series recording increased space, staff, facilities and
responsibilities, will also record an increase of workers
and of work in the new combined Biological Station,
Aquarium and Fish Hatchery. |
During the past year the usual work, both educational
and in research, has been carried on steadily. A party of
students and investigators occupied the Laboratory in the
Kaster vacation, and several collecting excursions were
arranged for their benefit. The new University of
Birmingham has, we are glad to report, engaged a work
place permanently in the Laboratory, at an annual rent;
and two students from the Zoological Department have
already been sent by Professor Bridge to carry on work.
Three Universities have now engaged work places in this
manner for the benefit of their Biological staffs, and in
the new Station we shall be able to offer increased space
and facilities to any other teaching or other institutions
(such as Museums) which desire to take advantage of the
opportunities for marine biological work which we can
afford.
We publish now, as an Appendix to this Report, the
“ Guide to the Aquarium,” which has been in preparation
for some time. It will also be printed separately for use
in the new Aquarium.
Tue Sratton ReEcorp.
During the past year the following naturalists have
worked at the Biological Station, in addition to: the
MARINE BIOLOGICAL STATION AT PORT ERIN. 29
Curator (Mr. H. C. Chadwick), who has been in constant
attendance with the exception of his usual holiday.
DATE. NAME. WORK,
Hebruary 9th )\ Prof. Herdman ae ae eae fea :
to 11th) Mr. I. C. Thompson wid Pa see) Official,
April aA ror 4} Miss England, Owens College... ».. General,
April 9th ycneida
to Miss ite R. Thornely, Liverpool ... and
Rand Polyzoa,
April ie 29nd Miss Lunt, Owens College... can ... General,
April 9 i Age ‘i Miss Jordan, Owens College Sy. ... General.
April a ioe Prof, Herdman _... selec .. Tunicata.
April a (My. F. W. Headley, Haileybury cones ) re ea
May 2nd (Me. O. L. V. Simpkinson, do, ve |
May 29th \ Mir Wilson, Manchester... Hee ... General.
to June 3rd )
June 15th (Prof. Herdman a “ihe an ee Official
to 18th | Mr. I. C. Thompson ties MUR aren Sen agree
July 15th )
to Miss M. Clarke, University, Birmingham. General.
August 17th j
August Ps th Mr. Tattersall, Univ. College, Liverpool... General.
August 13th ) ( Marine Insects
to -Mr. A, D. Imms, University, Birmingham + and
September 3rd | | General.
Rephen EP Ba | Mr. H. Yates... Polycheta.
September 21st {| Prof. Herdman : “a nap ny aes
to 23rd { Mr. I. C. Thompson... ay bey a) Oierals
Photography
October find | Rev. T. S. Lea { of Marine
Y j Animals.
a Prof. Herdman . AS?
Mc. LC. Thompson... ... + oNosten
0 Te ORsI Metta er SF Ee
Mry A. ELolt; jun, +>... ae ae .» Hydrography
There have also been, as usual, visits from several
scientific men and Societies.
30 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
Mr. Chadwick reports to the Committee as follows :—
Curator’s REporT.
“The work of the Station has been carried on steadily
and -successfully throughout the year, and an average
number of students have availed themselves of the accom-
modation and facilities provided for the study of hving
marine animals and plants. The Easter party was this
year more than usually successful, and much good work
was done.
“In view of the addition of fish hatching and culture
to my curatorial duties, I have devoted a good deal of
time this year to the acquisition of knowledge of fishery
matters. During the month of March I spent a fortnight
at the Sea-fish Hatchery of the Lancashire and Western
Sea Fisheries Committee at Piel, Barrow, and, under the
able guidance of Mr. Andrew Scott, carefully studied the
apparatus and methods used there in hatching the eggs of
sea-fish. In trying to gain information from local fisher-
men at Port Hrin I have been less successful. Owing
partly to their lack of interest in anything that does not
directly affect the capture and sale of fish, and partly to
jealousy of each other, they can only with difficulty be
induced to give information, and their statements. are
often vague. One of them, F. Watterson, was, however,
good enough to keep the record given below, of the fish
taken by one boat during what is known as the “ winter
fishing ”’ of 1900-01. Fishing was frequently interrupted
by stormy weather, and the number of fish caught was
said to be below the average.
“Fishing with a drag net from the shore, locally kriowe
‘trawling,’ was carried on, as in previous years, early
in October, but. always after nightfall. On several occa-
sions large numbers of the Saithe or Coal-fish (Gadus virens)
MARINE BIOLOGICAL STATION AT PORT ERIN. 31
were taken; while grey Mullet (Mugi chelo), Turbot
(Rhombus maximus), and a fish rather mysteriously
referred to as “Salmon-trout’’ made up the catches in
small and varying numbers. The Saithe, locally known
as “ Bloghan,” is extensively fished with rod and line,
and the occurrence of fine and calm evenings at the time
named favoured good sport. ‘The “ back” herring fishery
appears to have been more than usually successful this
autumn, and it is worthy of note that on the Hast side of
the Island the capture of the fish involved the destruction
of an enormous quantity of spawn.
‘““T have continued my investigation of the fauna of
Port Erin Bay by collecting, at frequent intervals, on all
parts of the beach and by occasional dredging excursions.
The Nudibranch Galvina cingulata and the Crustacean
Athanas nitescens are now recorded for the first time, the
former having been taken in December, 1900, and the
latter in March, 1901. Polycera lessont was also found,
on June 18th. Two specimens. of the beautiful little
Polychete Gattiola spectabilis were found in a rock pool
early in February. This worm has not come under obser-
vation for some years past. I have devoted a good deal of
time to the study of the Compound Tunicates, and have
made some careful drawings for Professor Herdman of a
number of representative species. Mr. P. Nevill kindly
sent some Compound Tunicates and other animals,
obtained by diving, from below low-water mark at the
Battery Pier, Douglas.
“The Plankton fauna of the bay has resembled that of
former years. Noctiluca occurred very sparingly in one
tow-netting taken on January 11th, and in several taken
in August. It is remarkable that this widely distributed
organism should have been observed in enormous numbers
on the north coast of Anglesey by Professor Herdman
32 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
during August this year and last, when it was scarcely
represented here. Aurelia aurita, not uncommonly in-
fested by the Amphipod Hyperia, was abundant within
the limits of the bay in July and August; and during the
latter month, for the first time since I assumed the
curatorship, a species of Cyanea was well represented, but
none of the specimens seen were of large size. P2lema
octopus also occurred frequently, and some of the speci-
mens measured 12 to 15 inches across the umbrella. No
complete specimen of the Siphonophore Cupulita sarsi
came under observation, but many detached nectocalyces
were noticed in the tow-nettings in July and August.
Pleurobrachia has occurred in varying numbers from May
(when some of its early stages were seen) onwards, but
very few specimens of Beroe ovata were noticed this year.
A single Actinotrocha larva was taken on August 12th.
Ovkopleura, seldom absent from the surface fauna, was
extraordinarily abundant on January 11th and September
14th. Fish eggs were abundant on the surface in April,
and in one tow-netting taken by Professor Herdman on
the 10th of that month, those of the Flounder, Turbot,
Witch, Ling, Haddock, Cod and Dragonet were identified
by Mr. A. Scott.
“Several valuable additions to the Station Library
have been made during the year, the most noteworthy
being six volumes of Challenger Reports, presented by the
Lords of H.M. Treasury.
“T have paid a good deal of attention to the orders
received for living and preserved specimens, and have
successfully supplied several workers with quantities of
material for their investigations. It is, however, unfor-
tunate that the majority of these orders are received
during the winter months, when low tides occur after
dark, and unfavourable weather makes dredging almost
MARINE BIOLOGICAL STATION AT PORT ERIN. 33
impossible, especially in the absence of capable assistance.
“ Nearly 500 visitors were admitted to the Aquarium
during the season—a fairly large number when the
secluded situation of the building and the comparatively
small lodging capacity of the town are considered.
“The projected Fish Hatchery has greatly increased
the interest of fishermen and visitors in our work, and
probably accounts for the marked increase in the number
of the latter as compared with last year. Increased
experience has enabled me to keep the animals in health
for a much longer period than formerly, and the mortality
amongst them at the time when the summer temperature
was highest was much less than in former years. The
conger noticed in last year’s Report is still alive and
healthy. It takes food greedily whenever offered, and
will snap at a hand held over the edge of the tank; but,
though fed liberally at intervals, it does not appear to
have grown appreciably. Another conger has occupied
the same tank for some months past, but has only quite
recently begun to feed. The lobsters have attracted an .
extraordinary amount of attention on the part of visitors,
and I have been able to make some further observations
on their habits. I find that the carapace does not
invariably split along the median line when the shell is
east. The shallow wood tanks have not been disturbed
since their establishment in the early spring of 1898, and
now contain an interesting collection of well acclimatised
anemones. ‘In addition to these, such Molluscs as 7'rivea,
Tapes, Pectunculus, and various species of Venus have
lived therein for months, the first-named for over a year,
and a specimen of Linews marinus, that longest of long
worms, has lurked under a stone since the early spring,
always ready to display its sinuous length on the intro-
duction of a few morsels of fish, which it swallows in a
34 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
peculiar snake-like manner. <A large number of Ephyre
of Aurelia aurita disported themselves in one of the large
wall tanks during the greater part of March, and the small
Polychete Ophryotrocha puerilis has recurred each year
in one and the same tank.”’ [H. C. Cuapwick. |
Notes on Work Done In THE DISTRICT.
In addition to small boat collecting work in Port
Krin Bay, and occasional expeditions from Port St. Mary
to the Sugar-Loaf Caves and the Calf Sound, we had a
steamer dredging expedition on April 18th in the Lanea-
shire Sea Fisheries boat “ John Fell.” Hauls were taken
off the Calf Island, 18 fathoms, and at varying distances
to the North and West up to Contrary Head, Peel, where
we dredged in 20 fathoms. This was mainly a students’
expedition for those working in the Laboratory, but a
good deal of material was brought back which has been
distributed to our specialists and worked up. Miss
Thornely obtained 21 species of Hydroid Zoophytes,
including Perzgonimus repens, and four species of
Sertularella—S. polyzonias, S. rugosa, S. gays and S.
tenella; and 38 species of Polyzoa, including Cellaria
fistulosa and C. sinuosa, Buskia nitens and Cylindrecoum
pusillum.
Mr. Alfred Leicester and Mr. L. St. G. Byne have
published a paper on the Mollusca of the South end of the
Isle of Man, which appeared in the “Journal of
Conchology”’ for July, and which has already to our
knowledge attracted a couple of students of Conchology
to Port Erin.
Mr. A. D. Iuns reports as follows :—
“Upon the nomination of Professor 'T. W. Bridge, I
was enabled to occupy the table rented by the University
of Birmingham from August 13th until September Ath,
MARINE BIOLOGICAL STATION AT PORT ERIN. 35
1901. My time was mainly devoted to studying the
living conditions of many of the marine forms of animal
life occurring in the immediate neighbourhood of Port
Krin, and somewhat careful attention was especially
devoted to several marine insects which, as far as I have
been able to ascertain, have not hitherto been recorded
from the L.M.B.C. district.
7 “Among these Insecta, Machilis maritima (Leach)
was common about the cliffs and upon the walls of the
Biological Station, especially after dusk. I also took it
inside the Station at night, where it was attracted by the
lamp with which I was working; they seemed partial to
places which received the glare of the lamp. I think this
is somewhat interesting, since it points to the probability
that the insect may become domesticated, if it is not
already so, in fishermen’s cottages, &c., by the shore. As
is well known, its ally, Lepisma saccharina, is truly
domesticated in kitchens, bakehouses, &. <A Collem-
bolan closely allied to Anurida maritima (Guerin) Laboul.,
was plentiful, especially during bright calm weather, upon
the surfaces of the rock-pools and crawling over the weed,
at low tide, but is completely submerged at high water.
It differs from the true A. maritima in that it possesses a
tooth to the inner margin of the claw of each foot, and
further it has 9 elements, instead of 7-8, to the post-
antennal organ, and in its general form is somewhat more
robust in build. Its habits are similar to. those observed
for maritima by Laboulbene and Moniez. Another insect
of interest is a Chironomid larva which occurs in the rock
pools among Corallina officinalis. It belongs to the genus
Clumo of Haliday (Nat. Hist. Rev., vol. II., 1855, p. 52,
plate Il.); the only British species of the genus is C.
marinus (Hal.), which has been recorded from three
localities in Ireland and once from Hastings, and to which
36 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
species my examples may perhaps belong. I may add
that the Clunzo larva has only been recently described,
namely, by Carpenter (nt. Month. Mag., 1894, p. 129)
and Chevreul (Archiv. Zool. Gen. et Exp., p. 583).
“In conclusion, I wish to say that I am indebted to
Mr. H. C. Chadwick for much kind assistance throughout
my work.”
Sample tubes of Plankton specially rich in Diatoms
have been sent from time to time to Mr. T. Comber,
F.L.S., our well-known local authority on the Diatomacee,
and we hope to have some notes from him on the subject
in a future report.
Mr. Andrew Scott sends me the following Natural
History observations which he has made at Piel (Barrow
Channel) during the year : —
“In my paper* published since the last Annual
Report, which included the species then recorded, the
following were given as new to the district :—Glugea
lophii, Doflein, a Protozoan from the brain of the Angler
fish; Dactylocotyle pollachu, Van Ben. and Hesse,
Octobothrium merlangi (Kubn), Phyllonella solee, Van
Ben. and Hesse, ? Placunella pini, Van Ben. and Hesse,
all Trematodes from the respective fishes, Pollack,
Whiting, Common Sole, and Yellow Gurnard; U pogebia
deltéura (Leach), a macrurid belonging to the Callian-
asside ; Cytheropteron humile, Brady and Norman, an
Ostracod which occurred abundantly in waterlogged
wood; and the following Copepod fish parasites :—Caligus
brevicaudatus n.sp. (recorded as Caligus sp. in the last
Report), from the mouth of the common Gurnard ; Oralzen
asellinus (Linn.), from the gill rakers of the yellow
Gurnard: Chondracanthus solee, Kréyer, from the gills of
*In Trans. Biol. Soc., vol. xv., p. 342.
MARINE BIOLOGICAL STATION AT PORT ERIN. 37
the common Sole; Brachiella ovalis (Kréyer), from the
gill rakers of the common and yellow Gurnards.
“ That paper brought the records down to April 30th,
1901, and the following additions to the fauna have since
turned up :—
“ TremMatopa.—Phyllocotyle gurnardi, Van Ben. and
Hesse, from the gills of yellow Gurnard T'rigla hirundo,
Beaumaris Bay, September 26th, 1901. Trematode sp.
from cloaca of Raza clavata, Beaumaris Bay, September
26th, 1901.
“ CESTOIDEA.—Tape worm from spiral valve of Angel
Fish, Rhina squatina, off-shore station, June 28th, 1901.
Tape worm from intestine of Brill, Bothus rhombus,
Beaumaris Bay, September 26th, 1901.
“ Macrura.—Javea nocturna, Nardo, two specimens
of the young stage of this Callianassid formerly known as
Trachilifer sp. (Jud.), Brook, were taken in a surface tow-
netting in mid-channel, off Piel, September 24th, 1901.
“ CopEropa (parasitic).—Caligus sp., in the branchial
chamber of Labraxr miatus and Labraa maculatus, oft-shore
stations; Mchthrogaleus coleoptratus (Guérin), on the skin
of the picked dog-fish Acanthias vulgaris, Beaumaris Bay,
September 26th, 1901; Pandarus bicolor, Leach, on the
skin of the picked dog-fish, Beaumaris Bay, September
26th, 1901; Clavella labract, Van Ben., on the gills of
Labrax miatus and Labrax maculatus, off-shore stations ;
? Lerneenicus musteli (Van Ben.), attached to the gill
rakers of the smooth hound Mustelus vulgaris, Carnarvon
Bay, June 19th, 1901; Lernea minuta, T. Scott, attached
to the gill rakers of the speckled Goby Gobius minutus,
Carnarvon Bay, and Beaumaris Bay, June 19th, 1901, and
September 26th, 1901; Thysanote impudica (Nordmann),
attached to the gill rakers of the yellow Gurnard T'rigla
lwvundo, Beaumaris Bay, June 20th, 1901; Lernewopoda
38 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
bidiscalis, W. F. de V. Kane, attached to the claspers of
the male Tope Galeus canis, Beaumaris Bay, June 20th,
1901; ? Hudactylina acuta, Van Ben., on the gills of the
angel fish Rhina squatina, off-shore station, June 28th,
1901; Eudactylina acanthi n.sp., on the gills of the picked
dog-fish Acanthius cele a Day Séplenia
26th, 1901.”’
Mr. Scott gives-the following notes in ———— to
Plankton work : — ;
“The collections of Plankton which have been taken
in the Barrow channel throughout the year, starting from
November Ist, 1900, show some interesting changes in the
pelagic organisms brought in by the flowing tide, and
appear to be worth calling attention to. The method
employed to collect the Plankton is to attach a tow-net to
the mooring buoy in the middle of that part of the Barrow
channel known as Piel Harbour, about half a mile from
the Laboratory. The net is attached to the buoy about
two hours before high water at Barrow, and left for a full
hour. The current at that time runs at 5 to 6 knots per
hour, and keeps the net at the surface, sufficient rope
being given to keep it clear of the buoy. The catch is
brought into the Laboratory and examined alive.
‘* Draroms.—Cosecinodiscus occurred in every gather-
ing except those taken in June, July and August, and
reached its maximum in numbers in March, April and
May. Biddulphia has a similar record, but was absent in
December, 1900, and the greatest abundance was reached
during February, March, April and May. Chetoceros was
very abundant in November and December, 1900; after
that it disappeared and did not occur again till September,
1901. Rhinosolenia only oceurred in May, but it was then
abundant.
“Atcm—aA species of gelatinous Alge made its
MARINE BIOLOGICAL STATION AT PORT ERIN. 39
appearance in great abundance during June and July
which completely choked the meshes of the net and pre-
vented the water from passing through. This gelatinous
alga also occurred in abundance off the North Wales coast
when I was on board the “John Fell” in the middle of
June, 1901.*
“ Protoz0a.—Nocteluca very abundant in November,
1900, giving the water a distinct brown colouration. It
gradually thinned off in December, and was absent from
all gatherings taken till March and June, 1901. Very
few occurred then, and none were seen till it again
appeared in numbers in September. Berdée: Small speci-
mens were common in November and December; in one
gathering taken in November 33 Berde were counted ; none
were taken in January, a few were seen in February and
March; it disappeared again after that month, but
reappeared in September.
“VERMES.—Sagitta was very abundant during
November and December, 1900, January, February and
March, 1901, gradually thinning off in April; none were
seen in May, but.a few turned up in June; none were seen
again till September.
“ CrustaceEA.—The common forms of Copepoda, such
as Centropages, Temora, Acartia and Ovrthona were pre-
sent in all gatherings taken except during July and
August; other forms made their appearance from time to
time. During the second week of March immense
numbers of Balanus nauplii were collected.”
‘T have received the following Report from Dr. O. V.
DaRBISHIRE : — :
“T worked at the Biological Station, Port Erin, for
*This is probably the same organism which was noted as causing
‘Foul water ’’ there in 1885 and 1887, and on other occasions since, by
Mr. Thompson ; See our first Annual L..M.B.C. Report, p. 55.—W. A. H.
40 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
about a fortnight during the last Easter vacation.
Primarily I was engaged in collecting material and notes
for a L.M.B.C. Memoir on Gigartina mamillosa. This
alga is extremely common along the coast of the district.
It usually occurs in company with Chondrus crispus, from
which plant it is readily distinguished by its infolded
margins, if the cystocarps are absent. A few specimens
of G. mamillosa so closely resembled G. pistillata that at
first I took them for representatives of that species. I
will refer to this point again in my Memoir. At this
time of the year G. mamillosa was well in fruit. The
cystocarps were nearly mature, or in many cases even
shedding the spores. In this respect G. mamillosa
resembles most Phyllophora species, and many other
Floridee, the ‘flowering’ of which takes place during
December and January, the fruit maturing during the
spring. I hope still to be able to find the tetraspores of
G. mamillosa—anknown as yet—which should also oceur
during the two months just mentioned.
“Species of Delesserta, Laurencia, &c., were ‘in
flower’ at Haster—Antherids, Procarps and Tetraspores
being frequently met with.
“T collected about 150 different species of marine
algze from Port Erin Bay, Port St. Mary and the Calf
Sound, Miss R. Jordan adding a few from Dalby. Chorda
tomentosa is the only new record. It occurs, at low-tide
mark, at the southern end of the sandy shore of Port Erin
Bay, in pools and on rocks. It is often considered only a
young form of Ch. filum. It differs, however, in the
structure of the hairs. These, always present in CA.
tomentosa, contain numerous brown plastids, and are the
chief organs of assimilation in this plant. In Ch. flum
these hairs are always colourless, assimilation being car-
ried on by the cells of the main axis of the plant.
MARINE BIOLOGICAL STATION AT PORT ERIN, 4]
“The Lichens of the district are mostly in very good
condition, and would well repay careful working through
from an ecological point of view, a remark which may be
made also with regard to the alge.”’
The two excellent illustrations which form figs. 1
and 2 are from photographs taken by Dr. Darbishire, and
_ represent some of the students that formed the Easter
party at work both outside and in the Laboratory. For
the use of the blocks we are indebted to the courtesy of
the “ Owens College Union Magazine,”’ where an interest-
ing article appeared in June on the Biological Station and
the work of the Easter party, written by one of the occu-
pants of the Owens College work-table.
Fisuery Work.
Although a certain amount of work, both directly and
indirectly bearing upon local fisheries, has gone on in the
past at Port Erin, it is evident that much more will have
to be done in the future. In the past we have had, for
example, the experimental hatching of various flat fish
and Gurnards and the experimental and observational
work on Oysters and disease, but in future fish hatching
and lobster rearing will be undertaken on a large scale
in the new hatchery, and various fisheries problems will
be investigated in the adjoining Aquarium and Labora-
tory. With a view to his new duties in that direction,
the Committee gave the Curator a few weeks’ special leave
of absence last spring in order that he might spend that
time at the Lancashire Sea-fish Hatchery at Piel, at the
height of the hatching season, so as to learn by actual
handling and co-operation the details of the methods
practised at that establishment, Mr. Chadwick has also
D
SREY AE erent
.
“been getting mto touch with the local fishermen and ue
“MARINE BIOLOGICAL STATION AT PORT ERIN. 43
©
ee
“started getting statistics of the local fishing. Here is a. tay
table showing the catches last spring of one of the
line boats fishing out of Port Hrin :—
Date: 1901. Lines. | Cop. |Happocx.| SKATE. | CONGER.
January 14th............ 3 35, — — _
i ee 4 40 ee ay y)
= PGE es aie onoce 6 23 a8 6 i
ss OEE cee. 3 7 = sie
i BAG oct veee ics die i ont a as ie
Heprwary, 7th ..-....+.2-. 6 103 1 2 =|
4 hes ee legs 90 1 7 1
is MOT orcs, 5 43 6: 6 1
- ‘Zit eee 5 53 2 3 a
a tipelm edie. i, 6 62 ES 2 3
a 7a ore 6 41 a 4 ue
5 0 5 86 1 3 i
i DOME ces 6 79 4 an oe
is Bo te hase: 4 56 1 is 1
fs 3,2 ee 4 45 2 9 2
March SU eres alelezinas 5 40 4 2 ao
e Seb! sees: 4 86 14 a weet
a HEN ec. 5 80 5 9 ee
a Beet eee sac. 5 4G a os va
‘ BGR soos. 6. 51 6 3 a
“ DOME ccs voecet: 6 82 3 om
April Pres sates 8 50 3 a _
In connection with the abundance of food for young
fishes in the waters round Port Hrin it may interest
readers to know of the following experience. The
numbers given may not be strictly accurate, but they are
probably a sufficiently close approximation to give a very
fair idea of the quantity of organisms in the water :—
On June 16th, 1901, Mr. Thompson and I took 3
hauls of a small tow-net having a mouth one foot in
diameter. The net was worked from our shellbend punt,
going very slowly, between the Biological Station and
Spaldrick Bay. The first haul was for a horizontal
MARINE BIOLOGICAL STATION AT PORT ERIN. 45
‘distance of about 500 feet, parallel with the shore. The
contents of the net were emptied into a jar of sea-water,
containing in all 1,000 cub. cm., which was thoroughly
stirred up and then 1 cub. cm. was taken out with a
pipette from the centre of the jar as a fair representative
sample. This was spread out in a large flat glass trough
under the microscope and the organisms were identified
and counted. The 1 cub. em. which formed -+— part
of the whole gathering was found to contain 12 species of
larger planktonic organisms, such as Copepoda, larval
worms, Medusoids, &c., and of these larger forms there
were counted 150 individuals easily visible to the unaided
eye. If then the sample was a fair one, the jar probably
contained about 150,000 larger organisms visible to the
eye, and these were strained out of a column of water of, at
the utmost, 500 feet in length and 1 foot in diameter,*
which would amount to about 400 cubic feet. That would
give 3/5 of these organisms per cubic foot, or 60 per
gallon. If the other two hauls, which we had not leisure
on that occasion to treat in the same way, contained
organisms in the same proportion, then we had caught in
the space of about an hour something like 450,000 Cope-
poda and larve, &c., visible to the eye, in addition to the
vast number of Diatoms, Peridinians, and other micro-
scopic forms which were seen to be present in abundance.
I must repeat that these numbers are only given as a
rough approximation, and that they probably under-
estimate the number of organisms that were present.
Also it must be remembered that the waters of the bay
frequently contain far fewer organisms and sometimes
‘
* Probably a good deal less, because of the pressure on the net prevent-
ing the whole of the water from passing through. Consequently the
estimation is a minimum one, and more organisms are really present than
appears from the calculation.
46 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
again probably have even more than on the above occa-
sion. These considerable variations in the amount of the
plankton are very striking at Port Erin, and taken along
with the frequent presence of an organism in one part of
the bay and not in another, impress one forcibly with
the fact of the irregularity, both qualitatively and
quantitatively, of the distribution of plankton in our seas.
An instance has been noticed by the Curator in his Report
where he points out that Noctiluca has been abundant for
two years in August off the North coast of Anglesey at a
time when it was very rare at Port Erin. How far such
irregularities in distribution can really be accounted for
by currents, tidal and otherwise, and can be co-related
with the physical characters of the water, has still to be
worked out in detail in our district.
Mr. Alfred Holt, junior, B.A. (Cantab.), has kindly
undertaken to examine for me in the Laboratory a number
of samples of water from various parts of the Irish Sea, in
order to determine how far such methods of taking the
densities and salinities as we can readily and rapidly apply
at sea or at the Biological Station are sufficiently accurate
and reliable. Although his work so far has been mainly
for the purpose of testing various methods and comparing
results, still it may be of interest to give here the specific
gravities, salinities and other chemical determinations of
a series of his samples, in order to give some idea of the
range over the district. A more detailed account of this
work, both as to methods and results, will be contributed
by Mr. Holt to the forthcoming Fisheries Laboratory
Report.
_ MARINE BIOLOGICAL STATION
AT PORT ERIN.
pe
“I
Dog te Sea |e
35 | Suu | Bg | BS | Hs | Bas
=e BaP As oH Be iE:
LOCALITIES. Pee Were kek de elie 5, qe ene
eae aa) aa lee Peas
g93 5 Oe ee m4 ip
nos A a vith
New Brighton ............ 1:02476 | 1:02605 | 17°25 | 31°17 | 51-20 | -1646
Piel (Barrow Channel)...| 1-02516 | 1:02647 | 17-88 | 32°30 | 53-66 | -1663
Port Erin (High water
cul fea co) ee 1:02585 | 1:02719 | 18°23 | 32°94 | 54:97 | -1672
Port Erin (Low water)...| 1:02582 | 1:02716 | 18-28 | 33-03 | 53-02 | :1608
Fleshwick (High water)..| 1:02594 | 1:02729 | 18-41 |. 33-26 | 53:20 | -1600
Crosby Channel (1 hour
TIC Serre age ene 1:02337 | 1:02459 | 16-56 | 29:92 | 55°50 | +1857
1 mile N. of Bar Light-
ship (Low water) ...... 1-02539 | 1:02671 | 18-05 | 32°61 | 54-29 |;-1667
EDOM foodies a ine oe 102390 | 1:02514 | 17°12 | 30:93 | 55:93 | :1778
Landing Stage (High |
12 G10 |S 1-02302 | 1:02421 | 16°60 | 29-99 | 51:74 | -1728
Landing Stage (Low
“02 7225) Sali ae 101631 | 1:01714 | 11°33 | 20°46 | 51-11 | 2500
45 miles §.H. of Douglas) 1:02579 | 1:02713 | 18°50 | 33°42 | 55-57 | -1672
30 miles §.K. of Douglas} 1:02606 | 1:02741 | 18-54 | 33°49 54:00 | -1615
15 miles 8.E. of Douglas} 1-02601 | 1:02736 | 18-45 | 33°33 | 52°38 | 1574
Douglas (Low water) ...| 102572 | 102706 | 18-49 | 33°40 | 54°29 | -1628
GuIDE TO THE AQUARIUM.
In last Report we alluded to the need that was
constantly felt of a short, simply-worded, well-illustrated
printed description of the common animals usually on
view in our tanks, as it is obviously impossible for the
Curator in the busy season to go round the Aquarium with
each visitor. We have had the matter in view for some
time, and have gradually been accumulating material
which has now been brought together to form the
appendix to the present Report. It is thus presented first
to our own subscribers, and will then be re-issued sepa-
rately as a Guide to the new Aquarium. The illustrations
have been reproduced by. photo-zincography from pen and
ink drawings by our Curator, Mr. Chadwick, and a very
large proportion of them are new and original figures
drawn direct from the animals. It is proposed that the
original drawings, which are of larger size than these
48 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
figures, should be framed and placed round the walls of
the new Aquarium alongside the appropriate tanks, so as
to aid visitors in the recognition of the various animals.
r
Tne New Biotocican Station anp Fisn Hatcuery.
As a result of the Report of the “ Tndustries ” Com-
mission which recommended a few years ago that, in the
interests of the insular fishing industries, a closer con-
nection should be established with the L.M.B.C., the
Bishop moved in the Tynwald Court on the 21st May last
that a Committee be appointed to take evidence and report
upon “the desirability of promoting a fish hatchery at
Port Erin in conjunction with the Liverpool Marine
Biology Committee.” This Committee visited Port Erin
on June 16th, the acting Chairman in the absence of the
Bishop being his Honour the Deemster Kneen, inspected
the present Biological Station and the proposed site for the
new institution, and held an inquiry at which much
detailed evidence was given, and plans were explained and
considered. This Committee reported to the Tynwald
Court on July 12th that “it is very desirable that a fish
hatchery should be established at Port Erin on the proposed
site near the breakwater,’ and recommended that a grant
of £2,000 be made for the erection of the building, and
that an annual sum of £200 be voted towards mainten-
ance. ‘They also recommended that a committee be
appointed which should be authorised to make arrange-
ments with the Harbour Board as to the site for the
building and tanks, and also with the Liverpool Marine
Biology Committee as to the management of the hatchery
and the use of the Laboratory and Aquarium. ‘The
Tynwald Court adopted the report, granted the necessary
sums and appointed the following as the Committee to
take charge of the institution :—The Lord Bishop (Chair-
MARINE BIOLOGICAL STATION AT PORT ERIN. 49
man), the Receiver-General (as Chairman of the Harbour
Commissioners, ev-officio), Mr. W. A. Hutchinson, Mr. D.
Maitland,’ Mr. J. Crellin, Professor Herdman, and Mr.
Robert Okell, F.L.S. (Secretary). |
The allocation of this grant received the sanction of
H.M. Treasury shortly afterwards, and the new Committee
held a meeting and got to work. In the meantime the
matter had been before a special meeting of the L.M.B.C.
held in Liverpool on September 10th, when Mr. Thompson
and Professor Herdman were appointed to confer with the
Manx Committee and conclude a suitable agreement. As
a result of several meetings between Mr. Thompson, as
Secretary of the L.M.B.C., and Mr. Okell, as Secretary of
the Manx Committee, an agreement was drawn up which
has since been submitted to both Committees and approved
of. The interests and liabilities of the two Committees
have been carefully considered and safeguarded, and their
cordial co-operation in the future provided for. Of the
three departments in the future institution the Laboratory
block will be wholly under the control of the L.M.B.C.,
the Hatchery block will belong solely to the Manx Com-
mittee, and the Aquarium in the centre will be managed
as a joint concern in the interests of both the scientific
and the economic work. ‘The two Committees contribute
equally to expenses of salaries and working, the Curator
of the. old Biological Station (Mr. H. C. Chadwick)
becomes Curator of the whole institution, with a fisher-
man assistant under him, and the Hon. Director of the
L.M.B.C. is recognised as being Director also of the
Hatchery. This, it is hoped, will secure unity and
economy of working and will result in the various depart-
ments being mutually helpful. The fishery work will be
of interest to the scientific students, and the investigations
in the Laboratory and Aquarium will be of importance in
50 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
connection with fishery problems. The Aquarium which,
with its museum of local marine animals in the gallery,
occupies the central block of the building, is the only part
open to the public, and will, it is hoped, be equally useful
(1) to the scientific workers in the Laboratory, (2) for
experiments and observations bearing on fishery questions,
and (3) as an educational influence which will be appre-
ciated by the more intelligent of our visitors.
The Manx Committee have lost no time since they
were appointed. An admirable site has been obtained
from the Harbour Commissioners on the South side of
Port Erin Bay near the base of the breakwater. Plans
and specifications have been drawn up, a tender from a
local firm of builders has been accepted, the contract for
the work has been signed, the foundations of the building
and the excavation of the large fish pond were commenced
on November 4th, and it is expected that the institution
will be completed and ready for occupation by May Ist,
1902. The Chart of Port Erin Bay given as fig. 3 shows
in square C. 4. the approximate site, but not the exact
shape of the building.
The details of the new building fall appropriately
within the scope of next year’s Report, in which they will
probably be fully described and illustrated. It must
suffice for the present to state that the plans show a plain
but substantial two-storey building of about 100 feet in
length by over 40 feet in breadth, with a yard, certain
outhouses, and a large pond. It has plenty of light and
plenty of space in all three of its departments, Laboratory,
Aquarium and Hatchery, and although not in any part
luxuriously equipped it ought to afford opportunity for
much useful work.
In this Report, to our own supporters, we naturally
look at the matter mainly from the point of view of the
op Cetineopun.
“FRLO
LRAN SNODTWE
iY
Dp ere7,
52, TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
L.M.B.C., and we feel that the change is one which offers
every prospect of increasing and improving our scientific
work. But we desire also to add that our Committee is
entering upon the joint undertaking in the most cordial
and sympathetic spirit, animated by the desire and the
determination to do all that is possible on the part of
scientific men to further the aims and objects of the
Hatchery Committee and the Manx Sea-Fisheries.
It may be pointed out, finally, that while this change
is advantageous to us in giving better accommodation and
larger opportunities, it also gives increased labour and
responsibility, and in no way relieves the L.M.B.C. of
financial burdens.
The Liverpool Committee retains its identity and
constitution exactly as before, and the subscriptions and
special donations from those who are kindly supporting
the work will be required fully as much in the new
building as they were in the old. The Manx Government
subsidy will be entirely applied to their own economic
work in connection with sea-fisheries, and will not be
available for the purely scientific work of the Biological
Station.
L.M.B.C. Mrmorrs AND OTHER PUBLICATIONS.
Since last Report three additional L.M.B.C. Memoirs
have been issued. ‘These are No. V., Atcyonrum, by
Professor Hickson, No. VI., on the Fish Parasites LERN=A
and LEPEOPHTHEIRUS, by Mr. Andrew Scott, and No. VIL.,
Linevs, by Mr. R. C. Punnett.
The eighth Memoir, the Puaicre, by Mr. Cole and Mr.
Johnstone, is now in type and will be issued before the
end of 1901, the ninth, on the red sea-weed CHonpRws, by
Dr. O. V. Darbishire, will follow soon, while others, such
as the OystTER, SAGITTA, CYTHERE, PATELLA and ANTEDON,
MARINE BIOLOGICAL STATION AT PORT ERIN. Da
are in active preparation. The lst of the Memoirs
published and in contemplation is now as follows :—
Memoir I. Ascrpra, W. A. Herdman, 60 pp., 5 Pls., 2s.
» I. Carpium, J. Johnstone, 92 pp., 7 Pls., 2s. 6d.
» LI. Ecuines, H. C. Chadwick, 36 pp., 5 Pls., 2s.
IV. Copium, R. J. H. Gibson and Helen Auld,
26 pp., 3 Pls., 1s. 6d.
i V. Aucyonium, 8. J. Hickson, 30 pp., 3 Pls., 1s. 6d.
» VI. LEPEoPHTHEIRUS AND LERN&A, Andrew Scott,
62 pp., 0 Pls., 2s.
» VII. Lineus, R. C. Punnett, 40 pp., 4 Pls., 2s.
» VIII. Puatcr, F. J. Cole and J. Johnstone, 252 pp.,
it Pls. 7s.
» 1X. Cuonprvs, O. V. Darbishire, 50 pp., 4 Pls.,
Buauta, Laura R. Thornely.
Oyster, W. A. Herdman and J. T. Jenkins.
Ostracop (CyTHERE), Andrew Scott.
Parevia, J. R. A. Davis and H. J. Fleure.
Antepon, H. C. Chadwick.
Drnpronotus, J. A. Clubb.
Prripinians, G. Murray and F. G. Whitting.
ZostrRA, R. J. Harvey Gibson.
Himanrirarta, C. E. Jones.
Diatoms, F. KE. Weiss.
Fucus, J. B. Farmer.
Botryitioipes, W. A. Herdman.
CurriLe-Fist (ELEpoNE), W. E. Hoyle.
Caxants, I. C. Thompson.
Actinia, J. A. Clubb.
Hyproi, K. T. Browne.
Myxing, F. J. Cole.
CaLcarrtous SponGE, R. Hanitsch.
ARENIcOoLA, J. H. Ashworth.
PorpotsE, A. M. Paterson,
54 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
In addition to these, other Memoirs will be arranged
for, on suitable types, such as Sagitta (by Mr. Cole), a
Cestode and a Turbellarian (by Mr. Shipley), Carcinus,
an Amphipod, and a Pycnogonid (probably by Dr. A. R.
Jackson).
We append to this Report : —
The Constitution and Laboratory Regulations
of the L.M.B.C. ;
The Hon. Treasurer’s Statement (which will be
found at p. 64), with the usual List of Subscribers
and Balance Sheet; and
The “ Guide to the Aquarium,” with numerous
illustrations of common marine animals, which is
issued in this form first to our members and friends
and will afterwards appear separately for use at
Port Erin.
MARINE BIOLOGICAL STATION AT PORT ERIN.
OU
OX
APPENDIX A.
THE LIVERPOOL MARINE BIOLOGY
COMMITTEE (1901).
Mr. R. D. Darsisuree, B.A., F.G.S., Manchester.
Pror. R. J. Harvey Gisson, M.A., F.L.S., Liverpool.
His Excettency Lorp HENNIKER, Governor of the Isle-
of-Man.
Pror. W. A. Herpman, D.Sc., F.R.S., F.L.8., Liverpool,
Chairman of the L.M.B.C., and Hon. Director of the
Biological Station.
Mr. W. EH. Hoyrrz, M.A., Owens College, Manchester.
Mr. P. M. C. Kermopg, Secy., Nat. Hist. Soc., Ramsey,
Isle-of-Man.
Me. A. Letcestrr, of Liverpool.
Sir James Poors, J.P., Liverpool.
Dr. Isaac Roperts, F'.R.S., formerly of Liverpool.
Mr. I. C. Tuompson, F.L.S., Liverpool, Hon. Treasurer.
Mr. A. O. Waker, F.L.S., J.P., Maidstone.
Mr. Arnoxtp T. Watson, F.L.S., Sheffield.
Curator of the Station—Mr. H. C. Cuapwicx.
CONSTITUTION OF THE L.M.B.C.
(Hstablished March, 1885.)
I.—The Ossxcr of the L.M.B.C. is to investigate the
Marine Fauna and Flora (and any related subjects such
as submarine geology and the physical condition of the
water) of Liverpool Bay and the neighbouring parts of
the Irish Sea and, if practicable, to establish and maintain
a Biological Station on some convenient part of the coast.
56 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
I1.—The Committrx shall consist of not more than 12
and not less than 10 members, of whom 3 shall form a
quorum; and a meeting shall be called at least once a
year for the purpose of arranging the Annual Report,
passing the Treasurer’s accounts, and transacting any
other necessary business. 3
I1Il.— During the year the Arrarrs of the Committee
shall be conducted by an Hon. Direcror, who shall be
Chairman of the Committee, and an Hon. TREASURER,
both of whom shall be appointed at the Annual Meeting,
-and shall be eligible for re-election.
IV.—Any Vacancies on the Committee, caused by
death or resignation, shall be filled by the election at
the Annual Meeting, of those who, by their work on the
Marine Biology of the district, or by their sympathy with
science, seem best fitted to help in advancing the work
of the Committee.
V.—The Ixvenses of the investigations, of the publi-
cation of results, and of the maintenance of the Biological
Station shall be defrayed by the Committee, who, for this
purpose, shall ask for subscriptions or donations from the
public, and for grants from scientific funds. |
V1I.—The Brorocican Station shall be used primarily
for the Exploring work cf the Committee, and the
SPECIMENS collected shall, so far as is necessary, be
placed in the first instance at the disposal of the members
of the Committee and other specialists who are reporting
upon groups of organisms; work places in the Biological
Station may, however, be rented by the week, month, or
year to students and others, and duplicate specimens
which, in the opinion of the Committee, can be spared
may be sold to museums and laboratories,
MARINE BIOLOGICAL STATION AT PORT ERIN, 9
LIVERPOOL MARINE BIOLOGICAL STATION
AT
PORT ERIN.
LABORATORY REGULATIONS.
I.—This Biological Station is under the control of the
Liverpool Marine Biological Committee, the executive of
which consists of the Hon. Director (Prof. Herdman,
F.R.S.) and the Hon. Treasurer (Mr. I. C. Thompson,
WEsS.).
I1.—In the absence of the Director, and of all other
members of the Committee, the Station is under the
temporary contro] of the Resident Curator (Mr. H. C.
Chadwick), who will keep the keys, and will decide, in the
event of any difficulty, which places are to be occupied by
workers, and how the tanks, boats, collecting apparatus,
&c., are to be employed.
IIJ.—The Resident Curator will be ready at all
reasonable hours and within reasonable limits to give
assistance to workers at the Station, and to do his best
to supply them with material for their investigations.
IV.—Visitors will be admitted, on payment of a small
specified charge, to see the Aquarium and the Station, so
Jong as it is found not to interfere with the scientific
work. Occasional lectures are given by members of the
Committee.
V.—Those who are entitled to work in the Station,
when there is room, and after formal application to the
Director, are:—(1) Annual Subscribers of one guinea or
upwards to the funds (each guinea subscribed entitling to
the use of a work place for three weeks), and (2) others
who are not annual subscribers, but who pay the ‘Treasurer
E
58 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
10s. per week for the accommodation and privileges.
Institutions, such as Colleges and Museums, may become
subscribers in order that a work place may be at the
disposal of their staff for a certain period annually; a
subscription of two guineas will secure a work place for
six weeks in the year, a subscription of five guineas for
four months, and a subscription of £10 for the whole year.
V1I—Kach worker is entitled to a work place opposite
a window in the Laboratory, and may make use of the
microscopes, reagents, and other apparatus, and of the
boats, dredges, tow-nets, &c., so far as is compatible with
the claims of other workers, and with the routine work of
the Station.
VII.—EKach worker will be allowed to use one pint of
methylated spirit per week free. Any further amount
required must be paid for. All dishes, jars, bottles, tubes,
and other glass may be used freely, but must not be
taken away from the Laboratory. Workers desirous of
making, preserving, or taking away collections of marine
animals and plants, can make special arrangements
with the Director or Treasurer in regard to bottles and
preservatives. Although workers in the Station are free
to make their own collections at Port Erin, it must be
clearly understood that (as in other Biological Stations)
no specimens must be taken for such purposes from the
Laboratory stock, nor from the Aquarium tanks, nor from
the steam-boat dredging expeditions, as these specimens
are the property of the Committee. The specimens in
the Laboratory stock are preserved for sale, the animals
in the tanks are for the instruction of visitors to the
Aquarium, and as all the expenses of steam-boat dredging
expeditions are defrayed by the Committee, the specimens
obtained on these occasions must be retained by the
Committee (a) for the use of the specialists working at
MARINE BIOLOGICAL STATION AT PORT ERIN. 59
the Fauna of Liverpool Bay, (6) to replenish the tanks,
and (c) to add to the stock of duplicate animals for sale
from the Laboratory.
V1III.—Kach worker at the Station is expected to lay
a paper on some of his results—or at least a short report
upon his work—before the Biological Society of Liverpool -
during the current or the following session.
IX.—AlI] subseriptions, payments, and other commu-
nications relating to finance, should be sent to the Hon.
Treasurer, Mr. I. C. Thompson, F.L.S., 53, Croxteth
Road, Liverpool. Applications for permission to work at
the Station, or for specimens, or any communications in
regard to the scientific work should be made to Professor
Herdman, F.R.S., University College, Liverpool.
60 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
: APPENDIX B.
HON. TREASURER’S STATEMENT.
As usual the list of subscribers and the balance-sheet
are appended, the latter showing a small adverse balance.
The report of the Director clearly indicates the neces-
sity there will be for kindly increased support by
subscriptions and donations when the new commodious
Biological Station is ready for occupation, as the Com-
mittee hope it may be early in the coming year.
As a result of the generous response made to the
Director’s appeal, a few years ago, by Mr. F. H. Gossage
and Mrs. Holt for special funds to be utilized in publishing
well illustrated papers and memoirs embodying the results
of local biological investigations, several important
memoirs have been issued during the year, and others will
shortly be ready for publication.
-The Treasurer will gladly receive the names of new
subscribers, with the view of continuing these publications
and of aiding in the increased working expenses, ‘and
further adding very materially to the already excellent
work achieved under the auspices of the L.M.B.C. since
its foundation, sixteen years ago.
Isaac C. THompson, Hon. Treasurer,
53, Croxteth Road, Liverpool.
"MARINE BIOLOGICAL STATION AT PORT ERIN.
~ SUBSCRIPTIONS ann DONATIONS.
61
Subscriptions. Donations.
Alcock, Dr., Goole, Yorkshire
Ayre, John W., Ripponden, Halifax
Bateson, Alfred, Styal, Manchester
Beaumont, W. J., Citadel Hill, Plymouth
Bickerton, Dr., 88, Rodney-street
Bickersteth, Dr., 2, Rodney-street
Brown, Prof. J. Campbell, Univ. Coll. ...
Browne, Edward T., B.A., 141 , Uxbridge-
road, Shepherd’s Bush, London
brunner, om J. /T.,. Bart., M.P.., Lipool...
Boyce, Prof., University College
Caton, Dr., 86, Rodney-street
Clague, Dr., Castletown, Isle of Man
Clubb, J. A., Public Museums, Liverpool
Coombe, John N., 4, Paradise-square,
Sheffield ae coi was
Comber, Thomas, J.P., Leighton, Parkgate
Crellin, John C., J.P., Andreas, I. of Man
England, Miss, Owens. College, Man-
chester : ae Sie ae
Gair, H. W., Smithdown-rd., Wavertree
Gamble, Sir David, C.B., St. Helens......
Gamble, F.W.,Owens College, Manchester
Gaskell, Holbrook, J.P., Woolton Wood
Gibson, Prof. R. J. Harvey, Waterloo ...
Gotch, Prof., Museum, Oxford ...
Halls, W. J., 85, Lord-street
Hanitsch, Dr., Museum, Singapore
a ao
Forward...£31
ee
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oqo ooo oqo o
£. Sa Oe
62 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
Subscriptions. Donations.
Forward..
Headley, F. W., Haileybury College,
Hertford si ao tee
Henderson, W. G., the late, Liverpool
Herdman, Prof., University College
Hewitt, David B., J.P., Northwich
Holland, Walter, Mossley Hill-road
Holt, Alfred, Crofton, Aigburth ...
Holt, Mrs., Sudley, Mossley Hill
Holt, R. D., 54, Ullet-road, Liverpool ...
Hoyle, W. E., Museum, Owens College
Isle of Man Natural History Society
Jarmay, Gustav, Hartford
Jones, C.W., J.P., Allerton Beeches
Jordan, Miss, Owens College, Manchester
Kermode, P. M. C., Hill-side, Ramsey ...
Lea, Rev. T. Simcox, St. Ambrose Vicar-
age, Widnes ...
Lea, Mrs. T. Simecox, ae
Leicester, Alfred, Dacre Hill, Rock Hee
Lewis, Dr. W. B., West Riding Asylum,
- Wakefield >:
Lunt, Miss A. J., 55, Gea: era. West
Didsbury
Manchester Nievodeantiet eee
Meade-King, H.W., J.P., the late
Meade-King, R. R., 4 Oldhall-street
Melly, W. R., 90, Chatham-street
Monks, F’. W., Brooklands, Warrington
Muspratt, E. K., Seaforth Hall ...
Newton, John, M.R.C.S., Prince’s Gate
Forward ...£65 4 6
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MARINE BIOLOGICAL STATION AT PORT ERIN. 63
Subscriptions. Donations.
Se
Forward...£65 4
Okell, Robert, B.A., Sutton, Douglas aS!
Paterson, Prof., University College eal
Rathbone, Mrs. Theo., Backwood, Neston 1 1
Rathbone, Miss May, Backwood, Neston 1 1
Rathbone, W., Greenbank eae apy ae)
Roberts, Isaac, F.B.S., Crowborough ee,
Simpkinson, Rev. O.L, V., Stoke-on-Trent 0 10
Simpson, J. Hope, Aigburth-drive lek
Smith, A. T., 35, Castle-street ... dts |
Somerville, Alex., Hillhead, Glasgow eat!
Talbot, Rev. T. U., Douglas, Isle of Man 1 1
Thompson, Isaac C., 53, Croxteth-road... 2 2
Thornely, The Misses, Aigburth-Hall-rd. 1 1
Timmis, T. Sutton, Cleveley, Allerton ... 2 2
Holl. Me; Kirby Park, Kirby ... Pete eh il
Walker, A. O., Uleombe Place, Maidstone 3 3
Walker, Horace, South Lodge, Princes-pk. 1 1
Watson, A. T., Tapton-crescent, Sheffield 1 1
Weiss, Prof. F. E., Owens College,
Manchester lee |
Wiglesworth, Dr., Rainhill es
Wilson, J. H., 24, Bune Street, Son 0 10
Yates, Beaty, 79, Shude-hill, Neon ic eee dk
Se. @ (epee 2 e7e7e 2 2 2S o7e 2] 2 S302
Soo =
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SUBSCRIPTIONS FOR THE Hire oF CoLLEGEe ‘‘ WorK-TABLES.”’
Owens College, Manchester
University College, Liverpool
Birmingham University
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Liverpool Marine Biology Committee,
PORE ERIN
PeeeOGICAL STATION.
PGUIDE
POP A WEL,
AQUARIUM:
Being a Short Account of some of the Common
Marine Animals of the Neighbourhood.
WITH ILLUSTRATIONS.
PRICE THREE PENCE.
LIVERPOOL:
C. TIntinG & Co., PRINTERS, 53, VICTORIA STREET.
EO) OF Zi,
F
66 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
Liverpool Marine Biology Committee.
Executive.
Chairman and Honorary Director of the Laboratory :
Proressorn W. A. Herpman, F.R.S., University
College, Liverpool.
Honorary Treasurer and Secretary :
Mr. Isaac C. THompson, F.L.S., 58, Croxteth Road,
Liverpool.
Committee.
Mr. R. D. Darsisutre, F.G.S., Manchester.
Pror. R. J. Harvey Grsson, F'.L.8., Liverpool.
His Excettency Lorp HENNIKER, Isle-of-Man.
Mr. W. HE. Hoyret, M.A., Owens College, Manchestems
Mr. P. M. C. Kermope, Ramsey, Isle-of-Man.
Mr. A. Leicester, Liverpool.
Sir James Poors, J.P., Liverpool.
Dr. Isaac Rozerrs, F.R.S., formerly of Liverpool.
Mr. A. O. Warker, J.P., F.L.S., Maidstone.
Mr. Arnotp T. Warson, F.L.S., Sheffield.
Curator of the Biological Station :
Mr. H. C. Cuapwick, Port Erin.
MARINE BIOLOGICAL STATION AT PORT ERIN. 67
Gute To THE Port Erin Aouarium.
Intropuctory Norte.
Tue Port Erin Biological Station was established by the
Liverpool Marine Biology Committee primarily for pur-
poses of scientific research. The first building, the
Laboratory, was opened by Sir Spencer Walpole, then
Lieutenant-Governor of the Isle of Man, in June, 1892;
and the second building, the Aquarium, was added in
March, 1893, for the double purpose of permitting of
observational and experimental work, and of enabling the
public to see something of the wonderful variety and
interest of life in the ocean and on the sea-shore.
It is evident to us, both from our own limited experi-
ence in this‘small Aquarium, and also from the history of
other similar but larger institutions elsewhere, that much
public interest can be excited and much useful educa-
tional work accomplished by well-arranged and adequately
stocked and properly kept marine tanks, especially if
combined with scientific guidance and personal exposition.
The latter, however, although very desirable, is not abso-
lutely necessary, and is not always possible, as it some-
times makes too severe a strain upon the limited time that
the Curator can spare from his other duties. It is hoped
by the Committee that the present little guide, drawn up
by the Hon. Director, with illustrations by the Curator,
Mr. H. C. Chadwick, will enable visitors to the Aquarium
68 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
to study the tanks and specimens for themselves with
intelligent interest, to recognise representatives of the
leading groups of marine animals, and to make some
acquaintance with the nature and range, the beauty and
the importance of the living things of our seas.
The majority of the figures are original, and were
drawn by Mr. Chadwick from specimens found at Port
Erin; the rest were copied more or less closely from well-
known works of the following authors:—Claus, Gosse,
Savile Kent, Jeffrey Bell, Hickson, McIntosh, Watson,
Balfour, Brady, Herdman, Sars, Korscheldt and Heider,
Jeffreys, Day, and Alder and Hancock.
Soon after this guide is printed, it is hoped that the
old Biological Station will be vacated, and that the Liver-
pool Marine Biology Committee will move into the more
commodious new Laboratory and Aquarium now being
erected in conjunction with the Government Fish
Hatchery on the South side of the bay. The conditions
and requirements of that new institution have been kept
in view in choosing the groups and types to be described
and illustrated in the pages that. follow.
W. A. HERDMAN.
University College, Liverpool,
November, 1901.
MARINE BIOLOGICAL STATION AT PORT ERIN. 69
PaO OZ, Ora.
(Hig! 1)
The lowest and simplest animals in the sea are not,
as some seaside visitors suppose, the jelly-fishes, zoopiytes,
and sea-anemones, nor even the sponges, but they are
minute delicate creatures, the Protozoa, found swimming
in the clear water or lying on the mud and sea-weeds, and
Hie: T.
for the most part far too small to be seen without the
microscope. And yet they are of immense importance in
the world. They are very numerous, and form the food of
larger animals in the sea. Many of them are eaten
directly by young fishes, and a French naturalist has
70 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
calculated that the Sardine takes as a meal about
20,000,000 of the small Ceratewm tripos shown in fig. I.
at 2; while Professor Hensen has found 130 millions of
them in 10 cubic metres of water from the Baltic. This
and other kinds of Ceratcwm (1 and 3) are one of the chief
causes of the luminosity or “ phosphorescence ”’ of the sea.
Another little Protozoon which frequently causes the sea
to sparkle with hight in the night is Noctiluca miliaris (fig.
I., 5), which is occasionally present in great abundance in
the Irish Sea. These all swim on the surface of the sea,
but there are many other Protozoa which have heavy
shells, and are usually found on the bottom or attached
to other objects. A good example of this is Rotalia
beccarw seen at 4, and belonging to the Foraminifera. In
some parts of the world Foraminifera are so abundant that
their minute limy shells accumulate as enormous deposits
covering many million square miles of the floor of the
ocean, and those that existed in former times now build
up mountain ranges in some parts of the world. There
are other Protozoa occasionally seen at the seaside, such
as Lolliculina ampulla (No. 6), enclosed in a delicate shell
and protruding its soft body, bearing a fringe of numerous
delicate hair-like filaments, by the lashing of which food
particles are wafted to the mouth; and Tvntennus
campanula (No. 7), a somewhat similar form, which floats
in the sea and can be captured by a fine muslin net.
There is a group of microscopic plants, the Diatoms,
which is worthy of attention because of its great import-
ance as a food of animals. Diatoms are unicellular Alge,
and a few of the commoner forms are shown in the figure:
8 is a Biddulpha, 9 a Coscinodiscus, 10 is Chaetoceras
secundum, and 11 Bacteriastrum varians.
Fully detailed reports upon the Foraminifera of our
district by Mr. Siddall and others, and upon the Diatoms
MARINE BIOLOGICAL STATION AT PORT ERIN. ie
by Dr. Stolterfoth, will be found in the volumes of
“Fauna of Liverpool Bay,’ published by the L.M.B.C.
The rest of the marine plants, or sea-weeds, have been
reported on by Professor Harvey Gibson.
PORIFERA.
(Fig. IL.)
We all know the bath sponge, but some people do not
realise that it is only the horny skeleton of an animal,
and that there are many sponges living in our own seas,
some of which also form horny skeletons, but which would
not be suitable for domestic use because of their contain-
ing numerous sharp-pointed glassy spicules or bristles
which strengthen and protect the body wall.
If we omit the minute and very simple unicellular
Protozoa, sponges are the lowest of animals. They are the
lowest of the “‘ Metazoa,’ or animals whose bodies are
built up of more than one cell. All animals from sponges
upwards to the highest are Metazoa, so the primary classi-
fication of the Animal Kingdom is into—(1) Protozoa, the
first, lowest and simplest animals, and (2) Metazoa, all the
rest. Wherever there are rocks and sea-weeds you can
find sponges at low tide. For the most part they are
found on the lower surface of stones, or in crevices of
rocks, or sticking on the roots of large sea-weeds. Fig.
IL. shows 3 very common kinds of British sponges which
are found almost everywhere round our coasts. Sycon
ciliatum (1) and Sycon (or Grantia) compressum (2) like
many others, have microscopic spicules made of hard chalk
or carbonate of lime, while in most of our sponges, as 1n
72, - TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
the crumb-of-bread sponge (Halichondria panicea), shown
at 3, the spicules are of silica or flint. This enables us to
distinguish two important sets of sponges, the Calcareous
and the Siliceous.
Sponges were at first thought to be lifeless, then for
a time they were regarded as plants. Professor Grant,
after whom a common sponge was called “ Grantia,” first
Hie. EL.
showed that they were animals, and that while alive a
current of sea-water passes through the sponge—in by
minute pores all over the surface, and out by one or more
larger crater-like openings.
The reports upon the sponges of our district have been
written by Dr. R. Hanitsch.
MARINE BIOLOGICAL STATION AT PORT ERIN. 73
COMLENTERATA.
(Figs. IIT. to VI.)
This important group of animals includes the plant-
like Zoophytes, the Medusz or jelly-fishes, and our
familiar Sea Anemones, as well as many animals, such as
the reef-building corals, which are not found in our seas.
BiG ell
Fig. III. shows pieces of several of our commonest British
Zoophytes. They are all colonies or assemblages of small
animals united together and fixed to one spot so as to
have a rooted plant-like appearance. But although rooted
and branched, and known as animal-plants (Zoophytes), it
must be remembered that these colonies are true animals,
and are moreover not the lowest animals, or those nearest
74 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
to plants, but are distinctly higher than the Protozoa and
the Sponges. A piece of one of the “ Sea-firs,” or Sertu-
larian Zoophytes, is shown, natural size, at 3 (Sertularia
abietina), where each of the little angular enlargements or
projections on the stem and branches is a horny cup con-
taining one of the members of the colony. _ Another
Sertularian Zoophyte (Sertularella polyzonias) is seen en-
larged in the living condition, under the microscope, at 1.
The little members of the colony (the Zooids) are seen
protruded from their delicate horny cases. Each has an
open mouth surrounded by about 20 delicate filaments,
the tentacles, by means of which the Zooid catches food
from the surrounding water. Hach such Zooid is very
similar in structure and appearance to the little fresh-
water Hydra, and consequently these colonies are fre-
quently called “ Hydroid Zoophytes.”’
Another common and closely related kind of Hydroid
Zoophyte (Obelia geniculata) is seen at 2. This is called a
‘“Campanularian ’ Zoophyte because each cup containing
a Zooid is bell-shaped and placed at the end of a ringed
twig or handle. This figure also shows certain larger
cases, in which are formed special buds that become
detached as little glassy bells or jelly-fishes for the purpose
of producing and scattering the eggs that will eventually
give rise to new colonies. The fixed Hydroid Zoophyte
thus gives rise by budding to free-swimming Medusz
(like that shown at 10, fig. XII.); and the Medusa pro-
duces eggs which give rise to fixed Zoophytes. Such a
life-history is an example of “ alternation of generations.”
Various reports upon the Hydroid Zoophytes, by Miss
L. R. Thornely, will be found in our volumes. Mr. HK. T. ,
Browne has contributed some papers on the Meduse from
work done at Port Erin.
Many of the smaller jelly-fishes of our seas are there-
MARINE BIOLOGICAL STATION AT PORT ERIN. 75
fore merely free-swimming stages in the life-history of
Hydroid Zoophytes, and these are frequently spoken of as
“Medusoids.”” Some of our larger Meduse, however,
such as the Awrelia shown in fig. LV. are not produced as
buds on a fixed Zoophyte colony, but have a somewhat
different life-history. As fig. [V. shows, the fertilised egg
of an Aurelia becomes an ovate free-swimming embryo
Fic. IV.
which settles down and grows gradually into a Hydra-like
Zooid with a mouth and long tentacles. Then the body
becomes transversely constricted and divided into many
pieces, which, when completely separated, lie like a pile of
saucers or soup-plates. As they float away from the pile
each such ‘‘ Hphyra” is seen to be a little Medusa, and
they grow into young Aurelias.
76 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
Amongst the rarer of the large Medusze which enter
Port Erin Bay there is one (Pelagia perla) which is
marvellously phosphorescent, glowing in the water like a
ball of incandescent metal.
Sea-anemones are abundant and varied round the
South end of the Isle of Man. Fig. V. shows several of _
the more important kinds found at Port Erin, most of
/Halcampa chrysanthellum. 2 Actinia equina. 3. Metridium dianthus.
4Sagarlia venusta. 5 Bunoedes verrucosa
which are generally on view in the Aquarium. Adctznza
equina (or A. mesembryanthemum), No. 2, is the common
dark red, smooth-bodied anemone which sometimes has a
row of bright blue spherules round the body at the base of
the tentacles. Metridiwm (or Actinoloba) dianthus (3) 1s
the plumose anemone, found at low tide attached to the
blocks of the old breakwater. It is generally of a pure
MARINE BIOLOGICAL STATION AT PORT ERIN. VE
white colour, but pink specimens are sometimes found.
No. 4, Sagartia venusta, is a representative of a large group
of small anemones to which the brilliant red and white
ones of the Sugar-leaf Cave, and of the Clets in the Calf
Sound, and the cave-dwellers (S. troglodytes) of pools at
Fleshwick and elsewhere all belong. Halcampa
chrysanthellum is a small and simple form found occa-
sionally, and Bunodes verrucosa (or B. gemmacea), No. 5, is
a pink anemone found in the pools at Port Erin and easily
recognisable from its colour and evenly roughened or
papillose surface of the body. The large “crass ”’ (T'ealza
erassicornis) is often brilliantly striped and spotted with
red and white, and usually attaches sand, shells and
small stones to the outside of the body. We have one
anemone (Anemonia sulcata), the “snakelet,” which is
unable to retract the tentacles. Altogether we have found
more than 20 different kinds of sea-anemones in the
neighbourhood of Port Erin.
Mr. J. A. Clubb, of the Liverpool Free Public
Museum, is our local authority on sea-anemones.
Sea-anemones are the British representatives of the
reef-building corals of tropical seas. The coral animals
are colonies of polypes, each of which is somewhat like a
sea-anemone with a calcareous skeleton.
Our nearest representative of the Mediterranean
animal which forms the red coral of commerce, is
Aleyonium digitatum, sometimes known as ‘“‘ Dead men’s
fingers’ or “ Dead men’s toes.”’ This is a common, white,
or orange colony, of fleshy consistency and lobed shape
(see fig. VI., 1), which is found attached to the under side
of the great blocks of the old breakwater at low tide. The
surface of the colony is covered when alive and expanded
with anemone-like polypes, each of which has 8 fringed
tentacles surrounding a smali central mouth. No. 2 shows
78 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
a polype with its tentacles, and No. 3 some of the scattered
spicules of carbonate of lime which are found imbedded in
the flesh of the colony.
No. 4 shows another much rarer animal (Sarcodictyon
catenata), obtained by dredging in deep-water off Port
Erin. It is closely related to Alcyonium, and figures 2
and 5 show that the polypes are very similar, although the
colony of Sarcodictyon (No. 4) is merely a creeping red
rootlet or ‘“stolon’’ connecting the bases of the small
conical polypes and generally attached to a dead shell or
a piece of stone. No. 6 shows the spicules, which are red,
and cause the colour of the colony.
Professor Hickson, of Manchester, has written our
L.M.B.C. Memoir on Alcyoniwm, and Professor Herdman
has contributed some papers on Sarcodictyon to our
Reports.
MARINE BIOLOGICAL STATION AT PORT ERIN. 79
ECHINODERMATA.
(Figs. VII. and VIIT.)
Star-fishes, Sand-stars, Brittle-stars, Feather-stars,
Sea-urchins and Sea-cucumbers are all characterised by
having plates and spicules of lime in the skin which may
project from the surface as spines. Hence they are known
as “ prickly-skinned”’ animals (Echinodermata). They
also have as another important characteristic a remarkable
system of tubes containing a watery fluid, parts of which
can be protruded as suckers for locomotion. These suck-
ing tubes can be seen acting as feet in star-fishes or sea-
urchins creeping up the glass of an aquarium. In the
Echinus shown at 5 (fig. VIII.) the short straight pointed
projections are calcareous spines, and the longer flexible
bodies are tube-feet, with suckers at their ends.
80 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
All the leading sections of existing Hchinodermata
are found at Port Erin, as follows :—
Crinoips, Feather-stars: Antedon rosaceus (fig. VIL.,
1) is found in deep water off the cliffs. In the
young (“‘pentacrinoid’”’) stage it is fixed by a
long stalk to the blades of the great brown oar-
weed (Laminaria), as shown at 2, and magnified
at 3.
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1 Asterina gibbosa 2 Asterias rubens 3 Ophiothria fragilis 4 Cucumeria planci 5 Echinus esculentus
Fie. VIII.
ASTERIDS, the common star-fish, Asterias rubens (fig.
VIII., 2), the Sun-star, Solaster papposus, and
the little Asterina gibbosa (fig. VIII., 1) are all
common at Port Erin, and are usually to be seen
in the tanks of the Aquarium. We have fre-
quently deep-water forms, such as the brilliant
red Porania pulvillus, the flat pentagonal
Palmipes placenta, and the pale strawberry
Stichaster roseus obtained on dredging expeditions.
MARINE BIOLOGICAL STATION AT PORT ERIN. 81
Oruturips, the sand-stars and brittle-stars, such as
Ophiothrix frags (fig. VIII., 3), have no
suckers on their tube-feet, and can be seen to have
an interesting new method of locomotion peculiar
to themselves; they jerk their bodies along by
alternately curving and straightening their
muscular many-jointed but fragile rays.
Ecurinips, Sea-urchins. In addition to the “regular ”
urchins, such as the large pink Hchinus esculentus
(fig. VIII., 5), found on the rocks and breakwater
at low tide, and the smaller dull green HF.
millcaris, found in the rock pools, there are at
Port Erin several kinds of the delicate “ heart”
’
or “oblique” urchins. The commonest of these
is E-chinocardium cordatum, which burrows a few
inches below the surface of the sand at low tide
in the centre of the beach.
HoLorHurips, Sea-cucumbers. The elongated, worm-
like body has a mouth surrounded by a crown of
tentacles at one end, while rows of sucking tube-
feet run down the 5 angles of the body. The
skin is strengthened by calcareous plates, often of
delicate and beautiful shapes under the micro-
scope. Cucumaria plana (fig. VIII. 4) is
dredged from deep water; another kind, Synapta
digitata, which has anchor-shaped spicules in the
skin, and no tube-feet, is found burrowing in
sandy gravel at low tide, in front of the
old Biological Station.
The eggs of all these common Hchinoderms develop
first into minute larve which are quite unlike the parents
in appearance and structure, and are found floating on the
surface of the sea. A larval Ophiurid, called “ Pluteus,”’
G
82, TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
is seen at 8, and a larval star-fish, called “ Bipinnaria,”
at 7, on fig. XIT.
Mr. H. C. Chadwick, the Curator of the Biological
Station, is our local authority on Echinodermata, and has
written a Memoir on Hehinus and several other papers for
our series of volumes.
VERMES.
(Figs. IX. and X.)
There are very many kinds of marine worms. Some
are microscopic, some are parasitic in or on other animals,
and some are lowly developed and very sluggish, and
inhabit mud and decaying sea-weeds, such as species of
Tetrastemma and Lineus, usually to be seen in our tanks.
We shall only illustrate here a few of the higher forms,
which are of fair size, of active habits, and are provided with
feet or bristles on the segments of the body. These higher
bristle-bearing marine worms, or “ Annelids,’ fall into
two sets—the Hrrantia, those that wander freely, creeping
over rocks and sea-weeds and under stones, and the Seden-
taria, those that inhabit tubes either fixed or moveable.
Amongst the commonest of our Errant Annelids are the
Nereis pelagica (1) and the Polynoe (Lepidonotus
squamatus) (2) shown in fig. 1X. No. 3 on the same figure
is a sedentary Annelid, the little Spororbis borealis, which
makes small spirally coiled white calcareous tubes on the
surface of stones, dead shells, and coarse sea-weeds all
round our shores. ‘The tube alone looks like a little shell,
but it is a worm which builds it, lives in it, and which
while alive can protrude from the opening a beautiful
plume of delicate branched tentacles as is seen in the
MARINE BIOLOGICAL STATION AT PORT ERIN. 838
figure (IX., 3). Serpula makes larger white calcareous
tubes, and is frequently seen in our tanks. These are
only a few of the very many kinds of bristle-bearing
marine worms or Annelids (for a full list see the report
in our “Fauna,” by Mr. J. Hornell). Other common
species are the fisherman’s lug-worm, Arenicola marina,
Ses \W oe
\Vi RQ
< SS
Nig
Pie. Ss,
and the sea-mouse, Aphrodite aculeata, both found
burrowing in sand. These and various other kinds are
generally to be seen in the shallow table tanks of the
Aquarium. Some of the Sedentary Annelids inhabit
tubes made of sand grains, and one of the members of the
84 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
Liverpool Committee, Mr. Arnold T. Watson, F.L.S., has
devoted much time and trouble to a careful study of the
methods in which these worms build up their very
beautiful houses by selecting and cementing together
particles taken from the surrounding sand and water.
The 6 little drawings on fig. X. are copied from the illus-
q)
Ee)
9
4
a
@
a)
a
8)
6
9)
)
:)
1)
1)
D)
.)
D
9)
~
Fie. X.
trations to one of Mr. Watson’s scientific papers, and they
show the front end of the body and sandy tube of T'erebella
conchilega, a common sedentary Annelid found in abund-
ance sticking out of the sand at low water near Port Erin
harbour. The middle figure in each row shows the head
of the worm placing and sticking together sand grains on
the top of its tube, like bricks on a wall.
MARINE BIOLOGICAL STATION AT PORT ERIN. 85
In the upper one it is forming the outer coating, and
in the lower the branched sandy filaments which surround
the mouth of the tube, whilst some of the figures shew how
the delicate tentacles capture and convey the sand grains,
or building material.
The right-hand lower figure shews the complete
structure. ‘Two curious pelagic or free-swimming worms
are shown in fig. XII., viz., Sagitta bipunctata at 2, and
Tomo pteris oniscof ormis at 4.
POLYZOA
(Fig. XT.)
On sea-weeds and under stones on the shore there are
many beautiful little colonies of worm-like animals to be
found, which, from their compound condition, are called
Fig. XI.
Polyzoa. Some are erect branched colonies (see fig. XI.,
1 and 4) lke Zoophytes, from which they can only be
distinguished by the microscope; others are flat and
86 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
incrusting (No. 3), and have a limy covering so as to be
quite hard and brittle; some of the colonies form net-
works extending for many square inches over the surfaces
of stones and the blades of the great brown oar-weed.
Flustra, the “sea mat’ (No. 1), is frequently found cast
up amongst sea-weeds. A small piece is shown magnified
at 2. Bugula (No. 4) is usually obtained by dredging;
part of the colony alive and expanded with polypites and
“pirds-head’’ processes is shown at 5. Forms lke
Lepralva (3) are found under stones and on shells in rock
pools. Specimens of these and other kinds of Polyzoa are
generally to be seen in our tanks at the Aquarium. The
reports in our “Fauna” are by Miss L. R. Thornely.
CRUSTACEA.
(Figs. XII. to XVIII.)
Crustaceans are animals such as crabs and lobsters,
shrimps and prawns, sand-hoppers and barnacles, and
innumerable smaller forms, “‘ water-fleas”’ and the like,
which abound in almost all parts of our seas. They all
have segmented bodies and jointed legs, and a hard shell
or covering to the body. They are, then, “ shell-fish”’ of ©
a kind, but they differ from the true shell-fish, such as
oysters and periwinkles, in having segments and legs.
Once the difference has been pointed out, no one can
mistake a shrimp-like shell-fish for a cockle-like shell-
fish. The former are Crustaceans and the latter Molluscs.
It is better to reserve the term shell-fish for the Molluses.
Among the most abundant of lower Crustaceans are the
rock-barnacles or acorn shells (Balanus) which are so
MARINE BIOLOGICAL STATION AT PORT ERIN. 87
abundant on rocks round our coast, and which by their
white limy shells closely placed on the dark grey rock of
Bradda Head give at low tide the appearance of a belt of
whitewash encircling the base of the cliff. The ship-
barnacle (Lepas) is closely related to Balanus. Its home
is on the open sea, but specimens are occasionally drifted
Hie, Sle
in to Port Erin. Once we captured a floating ship’s
bucket, which was covered inside and out with adhering
barnacles, some large and some small.
Most of the lower Crustacea (or Hntomostraca), unlike
the barnacles, are free-swimming; and from their small
88 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
size, somewhat insect-like appearance and legs, and their
active movements, some of them are often called “ water-
fleas.”
The most important group of the Entomostraca is the’
Copepoda. These little ‘‘ water-fleas”’ are exceedingly
abundant in the sea, and are of great economic import-
ance. It has been calculated that under each square
metre of the surface of the Baltic there are one million
Copepods, and that these use annually 4,730 millions of
the small Ceratiwm (see before) as food. Herrings feed
largely on Copepoda, and for a square mile of surface
water it has been shown that the annual consumption of
Copepoda is nearly 1,000 billion. Now a billion of Cope-
poda yields not less than 1,500 kilograms of dry organic
substance, and consequently in the 16 square miles of a
_ certain Baltic fishery the German biologists consider there
exists Copepod food for over 530 millions of Herring of an
average weight of 60 grammes.
Two common Copepods are shown in fig. XII.,
Temora longicornis at 9, and Pseudocalanus elongatus at
12. Each of these is about 4 of an inch in length. Myr.
Isaac C. Thompson, Hon. Treasurer of the Committee, is a
well-known authority on the Copepoda, and has written
many reports and papers published in our volumes.
When a fine muslin or silk net is drawn through the
water of Port Erin Bay for a few minutes, at almost any
time of the year, a number of small free-swimming plants
and animals are captured. Such organisms are known
collectively as “ Plankton.” Some of the more minute
and simple of these (Protozoa and Diatoms) were shown in
fig. I., while a number of the commoner and larger
kinds of “ Plankton” are represented in fig. XII. They
are evidently a mixture of young and old belonging to
different groups.
MARINE BIOLOGICAL STATION AT PORT ERIN. 89
peat
. 1s “ Nauplius,’ the larval stage of the lower
Crustacea, such as Copepoda.
. 1s Sagitta bipunctata, the arrow-worm, adult.
is the larval stage of a univalve Mollusc.
i Go no
. is an adult Tomopteris. onisciformis, a curious
transparent worm.
.-1s the larva of a Polyzoon.
. is a larva of a Polychaete worm (Verine).
. 1s the larva of a Star-fish.
s “ Pluteus,” the larva of an Ophiuroid.
tt (eps (On
co
. is an adult Copepod, Temora longicornis.
10. is Sarsia tubulosa, one of the Medusoids derived
from a Zoophyte.
11. is Pleurobrachia pileus, an adult Ctenophore
related to Meduse.
12. is Pseudocalanus elongatus, an adult Copepod:; and
15. is a pelagic fish-egg containing the young fish.
Coming now to rather higher and larger Crustacea,
Price XIII. illustrates the Amphipods or Sand-hoppers,
and figure XIV. the Isopods or Sea-slaters. These two
groups are closely related. In the Amphipods the body is
compressed from side to side, the back is generally curved,
the legs are long, and face some forwards and the others
backwards (see fig. XIII., 1), while a favourite mode of
locomotion is by a series of leaps. The leap is effected by
means of the hindmost or tail legs, which are bent for-
ward under the body, and then suddenly straightened out
so as to toss the body up in the air. The Amphipod shown
at 1 (Orchestia littorea) performs this action. Some kinds
of these Amphipods are extremely common on our sandy
shores, especially under stones or pieces of decaying sea-
weed. Others, like the Corophium grossipes shown at 2,
burrow in the sea-bottom, where some construct tubes and
nests of mud or sea-weeds. The curious skeleton-like
90 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
Caprella linearis (3) creeps up sea-weeds and Zoophytes,
and is sometimes seen in eccentric and acrobatic attitudes,
such as holding on to a branch by one claw or balancing
on one hind leg.
The commonest sand-hopper on Port Erin beach is ~
Orchestia gammarellus, and this sometimes, when a high
1 Orchestia lillorea 2 Corophium grossipes
3 Caprella linearis
Pigs XE.
tide is accompanied by a shower of rain, swarms out of the
sea on to the land in great quantity. On several occasions
during the last ten years these swarms have ascended the
concrete walls and steps from the beach, and have invaded
the Biological Station in great numbers, hopping over the
floor and climbing the walls, so as to get on to tables and
shelves.
MARINE BIOLOGICAL STATION AT PORT ERIN. 91
The Isopods, unlike the Amphipods, have for the
most part broader and flatter bodies (fig. XIV.), are
depressed from above downwards, have the legs shorter
and less conspicuous, and run or creep in place of leaping.
The tail legs which were used for leaping in the Amphi-
pods are in part breathing organs in the Isopods, and these
parts are enclosed within flap-like folding doors. Many of
the Isopods, although true water-breathers, can live the
1 Idothea ballica. 2. Astacilla longicornis 3 Ligia oceanica
Pig. XIV.
greater part of their time on land. JIdothea baltica, shown
at 1 (fig. XIV.), is completely aquatic, and lives on green
and brown sea-weeds, which it generally resembles closely
in colour; while Ligza oceanica (No. 3) is found at or even
above high tide mark, generally hiding in crevices of the
rock or between the stones of a pier during the day and
coming out to run about and feed at night. Astacdlla
longicornis (2) is of a white colour, and can only be
92 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
obtained from the deeper water outside the bay by
dredging. Our authority on the Amphipods and Isopods
and all higher Crustacea is Mr. A. O. Walker, a member
of the Committee. |
_ The highest Crustacea, such as crabs and lobsters, —
shrimps and prawns, are known as Decapoda because they
have 10 large or conspicuous legs or claws, 5 on each side
of the body. There are also about 14 other pairs of much
smaller legs, jaws and feelers which are not so conspicuous.
BiG. AaV..
Figure XV. shows (2) the common shrimp (Crangon.
vulgaris) and (1) one of our common prawns (Pandalus
annulicornis). Shrimps are nocturnal animals, lying for
the most part during the day buried in sand with only the
tips of the stalked eyes and the long delicate feelers pro-
MARINE, BIOLOGICAL STATION AT PORT ERIN. 93
jecting above the surface. Prawns, on the other hand,
are active during the day, prowling about constantly in
search of food. They live amongst rocks and sea-weed.
While alive their bodies are transparent or pale green,
usually beautifully marked with blue, and sometimes
green, yellow and purple lines. It is only after death
that the prawns become opaque, and more or less red in
colour. Shrimps are not so transparent when alive, and
do not become so red when boiled. They are grey, and
are usually speckled and mottled with black and white so
as to be exactly of the same appearance as the sand in
which they live. As the figure shows, the prawn has more
of a hump on its back than the shrimp, and can be easily
distinguished by the long spiny snout or “rostrum ”
between the eyes. ‘here are many other differences, and
it must also be remembered that we have several kinds of
shrimps and several different kinds of prawns in our seas.
The lobster (Homarus vulgaris) and the Norway lobster
(Nephrops norvegicus) are allied forms commonly caught
at Port Erin. The lobster produces from ten to twelve
thousand eggs at a time, which adhere to the legs on the
under surface of the tail of the female for many months
until they are hatched.. Countless millions of embryo
lobsters are lost every year through the “ berried ” females
being sent to market, which might be saved if the eggs
were cut off and reared in hatcheries.
There is one little prawn, Hippolyte (or Vurbsus)
varians, which is found amongst sea-weeds and in pools at
Port Erin, and which is of most varied colour according to
its surroundings. Specimens living amongst green weeds
are bright green in colour, and even the eggs laid by the
prawn are green; when amongst brown weeds, as it often
is, 16 is of a dark brown colour, and when in red and
‘variegated weeds it is red, or speckled with various
94 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
colours. Moreover, individuals can to a considerable
extent change their colour when the environment is
altered. The first Port Erin Annual Report (1893) con-
tained a short account of this animal, with a plate showing
the chief colour variations. Since then Messrs. Gamble
and Keeble have made a number of interesting experi-
ments, and have shown that at night the colour of all
varieties is a deep blue.
The Decapoda or higher Crustacea may be divided
into 3 sets :—
(1) Those that have the tail part or abdomen stretched
out behind the carapace or shield that covers the
head and thorax, as in lobsters, shrimps and
prawns (Macrura).
(2) Those where the abdomen is smaller and is folded
up underneath the carapace, as in_ crabs
(Brachyura).
(3) Those where the abdomen is neither completely
stretched out nor folded up, and is often
anomalous in shape (Anomura).
Figure XV. shows Macrura, fig. XVII. Brachyura, and
fic. XVI. two interesting kinds of Anomura, which we
generally have on view in the Aquarium. No. 2 is
c
Galathea squamifera, the “ squat-lobster,’ of which one
kind, of a blackish colour, is frequently found under
stones at low tide in Port Erin Bay, while another bright
red kind is obtained from deeper water by dredging. The
abdomen, it will be seen, is partially turned under the
body, but can be extended and flapped up and down when
swimming. The other figure (1 in fig. XVI.) shows a
“hermit crab” (Hupagurus prideauaii), with _ its
anomalous abdomen tucked into an old Molluscan spiral
shell, on the outside of which is a special kind of sea-
MARINE BIOLOGICAL STATION AT PORT ERIN. 95
anemone, Adamsia palliata. These two very unlike
animals, the hermit-crab and the sea-anemone, seem to be
mutually helpful; the crab carries about and incidentally
feeds the anemone, while the latter by its stinging threads
_ possibly keeps off fishes and other enemies, and so protects
its partner in this strange assoctation.
Gs Vel.
The highest of Decapod Crustacea are the Brachyura,
or Orabs, which have the abdomen permanently tucked up
under the carapace, so as not to be visible from above
(see fig. XVII.). The 10 conspicuous legs, which give
the name ‘“ Decapoda,” are clearly seen, while smaller
96 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
ones will be found about the mouth on the under side.
The appearance of the edible crab (Cancer pagurus) and of
the common shore crab (Carcinus menas) are well known ;
and the figure shows, at 1 the “ Fiddler” or swimming-
crab (Portunus puber) with flattened paddle-like hind legs,
Fie. XVII.
and at 2 one of the long-legged spider-crabs (Stenorhynchus
phalangium). Some of the spider-crabs are frequently
found to have their shells covered by a dense growth of
small sea-weeds, Zoophytes, and sponges, which to some —
extent conceal the crab from observation when it is in a
MARINE BIOLOGICAL STATION AT PORT ERIN. oF
rock pool or on the sea-shore at low tide. These sea-weeds
are found to be attached to little hooked spines, and
observations have shown that the crab attaches the sea-
weeds to them itself, apparently with a view to its own
disguise. We have generally some specimens of the
spider-crab, Hyas araneus, showing this concealment in
the tanks at Port Erin. Some other kinds of crabs are so
shaped and coloured as to be very hke the stones and other
objects amongst which they live.
All the crabs, as well as lebsters and shrimps, as they
grow larger, periodically throw off or “cast’”’ their hard
shells so as to permit of expansion. This process of
“ecdysis’’ may sometimes be seen taking place in an
aquarium, and it is so complete that not only is the outer
covering of the body shed, but every limb is drawn out of
its hard sheath, and the coverings of the eyes and the
delicate feelers and gills and even the cuticular lining of
the stomach are all cast off. For some time after this the
crab remains in a feeble and defenceless condition, but
swollen up with water, while its new shell is forming and
hardening. Such “soft ’’ crabs generally hide, are rarely
caught, and are recognised as being unfit for eating.
The life-history of the shore crab (Carcinus menas) is
‘interesting, and figure XVIII. shows some of the more
important free stages. The developing eggs are carried
about as an orange or dark brown mass underneath the |
abdomen, and when the young animals hatch out they are
called ‘“‘Zoeas*’ (1) and are quite unlike the old crab.
They have a large jointed abdomen and several long
spines sticking out from the body. They swim freely on
the surface of the sea, and are frequently caught in the
tow-net in summer and autumn. After a time the Zoea
grows larger, casts its skin, and becomes the next stage,
or ““ Megalopa”’ (2), which is much more like a crab, but
H
98 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
has very conspicuous eyes (hence its name), and still uses
the out-stretched abdomen for swimming on the sea-
surface. The older Megalopa begins to haunt the sea-
weedy shores and may be found in rock pools, and so
gradually grows into the smallest size of crab.
BIG. Vy Tee
Several reports upon our Crabs and other Higher
Crustacea, by Mr. A. O. Walker, will be found in our
volumes.
MARINE BIOLOGICAL STATION AT PORT ERIN. 99
MOLLUSCA.
(Figs. XIX. and XX.)
The Molluses, such as cockles and whelks, are the
true “shell-fish.”’ They have no joints or segments, and
no legs, and the soft body is covered by a hard limy shell
which is generally in only one (univalve, such as whelk) or
7
Ja! a
Xa Rm Au i, | i\\ I Ne Te y
SATIN i i a”
LAT : . \
Za im
! mint Lu su
Fre. XIX.
in two (bivalve, as in oyster and cockle) pieces, the valves.
A few Molluscs, the sea-slugs (fig. XX.), have no
shell when adult; while the Cuttlefishes have either no
shell, or a shell of a very special kind unlike that of
common univalves and bivalves. Figure XIX. shows a
100 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
group of representative Mollusca. 1 is the large scallop
(Pecten maavmus) with the rounded valve below and the
flat one above, the hinge where they join being at the
figure 1. Round the opening between the margins of the
valves is seen the soft edge of the body fringed with feelers
and a wonderful row of gleaming eyes. No. 2 is also a
bivalve (dLactra truncata), but 1s one which burrows in
sand by means of the long blade-like “ foot” seen to the
right of the figure (the animal’s anterior end), while at
the opposite (posterior) end is seen a double-barrelled
tubular arrangement by means of which supplies of water
are drawn into the body and ejected. The mussel (J/ytilus
edulis) and various kinds of Venus and Tapes are common
at Port Erin. No. 3 is the curious little slug-like Molluse
Chiton levis, frequently found under stones and in pools,
and quite exceptional! in having the shell represented by a
series of 8 pieces arranged along the back like a serres of
overlapping tiles. This leads to the ordinary univalves
(Gastropoda), of which we have an example in the common
dog-whelk (Purpura lapillus) at 4. These animals have
a broad creeping “ foot,” like that of the garden snail,
with the head and mouth in front and the tail behind.
The spirally coiled univalve shell is balanced on the back,
and all can be drawn up into it when the animal retreats.
In some cases there is a lid (the operculum) upon the tail
which fits the opening of the shell. The yellow egg-
capsules of Purpura are seen at 4a. From 10 to 20 eggs
are as a rule laid in each capsule, but of these only one
reaches maturity and emerges as a young Purpura. That
one is in every sense representative of its brothers and
sisters, as it has eaten all the rest. Various kinds of
periwinkle (Lzttorina) and the only kind of Cowrie (Cyprea
Europea) found in our seas are generally present in the
Aquarium.
MARINE BIOLOGICAL STATION AT PORT ERIN. 101
The two remaining animals shown in fig. XIX. are
Cuttlefishes (Cephalopoda). No. 5 is the common squid
(Loligo vulgaris), with 8 short “arms” and 2 longer
“tentacles ’’ attached to the head, and all of them bearing
suckers. Lo/igo has an internal shell shaped like a
short Roman sword, and made of a flexible transparent
horn-like substance. The remaining Cephalopod (No. 6)
is a kind of “Octopus” called Hledone cirrhosa. It has
only the 8 sucker-bearing arms, the body is shorter and
rounder than in the squid, and there is no shell of any
kind external or internal.
The soft skin of the Cuttlefishes is coloured yellow,
red and brown by little sacks full of pigment grains, and
these sacks can be so varied in shape as to change the tint
of the animal in accordance with its surroundings. In
httle baby cuttlefishes from } to } an inch. in length this
instantaneous change in colour, or “ blushing,’ can be
seen most beautifully as the little animals just hatched
from the egg dart about the tank from darker to lighter
coloured parts. |
Some Gastropods, such as the sea-hare (Aplysia
punctata), found by dredging in the bay, have very small
shells which do not cover the body.
The common limpet (Patella vulgata) is frequent on
the shore, and the beautiful transparent brown Helcion,
with its radiating lines of delicate turquoise blue, is found
at low tide on the blades and stems of the oar-weed.
Reports upon the various groups of Mollusca, by Mr.
R. D. Darbishire, Mr. F. Archer, Mr. W. HE. Hoyle and
Mr. A. Leicester will be found in the volumes of our
“Fauna.”
There is one set of Molluscs related to the ordinary
univalve Gastropods which have lost their shells. These
are the Nudibranchs or sea-slugs, four common kinds of
102 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
which are shown in fig. XX. No. 1 is the large yellow
sea-lemon (Archidoris tuberculata) frequently found in
rock pools during the spring and summer; 2 is the rarer
and smaller Polycera quadrilineata, marked with yellow
spots and found sometimes creeping on the blades of
Laminaria; 3 is Holts tricolor, one of the most graceful
and brilliantly coloured of the sea-slugs; and 4 is the
httle Doto coronata found on colonies of Zoophytes, upon
which it feeds. The brightly-coloured projections on the
back of Zolis have batteries of microscopic stinging
threads which can be discharged instantaneously into any
offending animal. Those sea-slugs which have no sting-
ing organs are for the most part coloured and shaped so as
to closely resemble their natural surroundings, and so
escape the observation of their enemies, while those (like
Holts) with offensive organs are conspicuous and_ bril-
liantly coloured, as if to warn other animals to avoid
them. In losing the shell these Molluscs have lost a pro-
MARINE BIOLOGICAL STATION AT PORT ERIN. 103
tection against injury, and this loss is compensated by the
colours and appearance of the soft bodies, which in some
cases are of a protecting and in other cases of a warning
nature. ‘The spawn of the sea-slugs is deposited in long
ribbon-like or cord-like convoluted white masses on stones
and weeds. A small piece contains many hundreds of
minute embryos which, when hatched, have for a time
ttle cap-like shells. This leads us to believe that the
sea-slugs are descended from ordinary shell-bearing
Molluscs.
Papers and reports upon our Nudibranchs, by
Professor Herdman and Mr. Clubb, will be found in our
volumes.
PUN CAT A :
(Fie. XXL.)
The Ascidians, or sea-squirts, are not so well known
to the public as they deserve to be. They are very
common, very varied and some of them very beautiful.
Most of them when adult stick to stones or sea-weeds, and
they are of two kinds—the Simple Ascidians and the
Compound Ascidians. A Simple Ascidian, such as Ascidia
(fig. XXIJ. 1), is a grey sack-like body from 1 to 6 inches
in length, having a tough skin (the “Tunic,” hence
Tunicata) and 2 openings through one of which the sea-
water is drawn in, while it is squirted out through the
other. When touched incautiously, the animal contracts
and emits sudden jets of sea-water from both apertures,
thus vindicating its title to the popular name “ sea-squirt.”’
The name Ascidian (from the Greek “ Ascos,” a leathern
double-necked bottle) is given in reference to the bag-like
104. TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
shape and the 2 apertures. There are many interesting
and some puzzling points in connection with the structure
and mode of life of Ascedza, but these would require many
figures and a microscopic examination of the animal for
their exposition. Another simple Ascidian which we fre-
quently have in the Aquarium is Styelopsis grossularta (2),
“the red-currant squirter of the sugar-loaf rock,” as it has
been called, because of the myriads which cover with a
red papillated surface many square yards of the cliff in
the beautiful caves near Spanish Head.
Compound Ascidians are colonies each member of
Fie. XX.
which is very much like a simple Ascidian in structure,
but they are all united together by one covering or tunic.
A common and very brightly coloured kind of Compound
Ascidian is Botrylius, shown at 5 in fig. XXI., and com-
monly found under stones about low-water mark. The
colony is marked with bright stars and wheels, each ray of
which is a separate member of the colony, with complete
organisation of its own. There are many other kinds of
Compound Ascidians (such as that shown at 4); they rival
the sponges in their curious shapes and brilliant colours.
MARINE BIOLOGICAL STATION AT PORT ERIN. 105
No. 3 is Clavelina, where beautifully transparent indi-
viduals are united by a creeping root. It is sometimes
found in the deeper pools at Port Erin.
The egg of an Ascidian develops into a minute
tadpole-shaped larva which has a back-bone running along
its tail and a nervous system with a brain, containing an
eyeandanear. In fact, the structure of this Ascidian larva
is very like that of any young vertebrate animal, and if it
remained in this condition for life it would be proper to
classify it along with the lowest fish-like vertebrates. But
it does not so remain. After a brief free-swimming
existence it becomes attached to a rock or sea-weed, and
settles down for the rest of its life. Then degeneration
sets in. The backbone, the brain, the eye and the ear—
all the evidence of its high organisation and active early
life—break up and disappear, and the free tadpole becomes
reduced to the sedentary sack-like Ascidian. This life-
history is a good example of degeneration, but it also
shows us that Ascidians are derived from ancestors which
were once related to the backboned animals.
There is one of the Tunicata which remains free-
swimming all its life, and has a backbone in its tail. It
is called Appendicularia, and we frequently catch it in the
tow-net in Port Erin bay.
The reports upon the Tunicata in our series are by
Professor Herdman, and the first of the L.M.B.C. Memoirs
is on “ Ascidia.”
FISHES.
(Fig. X XIT.)
There are about 150 different kinds of fishes found in
the Irish Sea around the Isle of Man. Some of these are
the well-known edible fish belonging chiefly to the Cod
I
106 ‘TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
family (Cod, Hake, Haddock and Whiting), the Flat-fish
family (Soles, Plaice, Dabs and Flounders), and the
Herring family. Others are rare fishes only occasionally
seen, such as the Sturgeon, Torpedo, Tunny and Thresher.
Others again are the voracious cartilaginous fish, such as
Skates and Rays, Sharks and Dog-fishes. Finally, there
are a very large number of curious and interesting little
=~ Se
6,
Bie. SX:
shore fishes to be found in rock pools and under stones,
some of which are generally to be seen in the Aquarium.
Three of the more common of these are shown in figure
XXII. No.1 is the Bull-head (Cottus scorpius), No. 2 the
common Shanny (Blennius pholis), and No. 3 a little pipe
fish (Nerophis lumbriciformis). The little sucker fishes
(Lepadogaster bimaculatus), the Butter fish (Centronotus
MARINE BIOLOGICAL STATION AT PORT ERIN: 107
gunnellus) and the Conger eel are also usually to be seen
in our tanks. it
Although most of these shore fishes lay their eggs in
spring under stones or in crevices or on old shells in the
sand, the majority of the fish we eat from the sea (with
the exception of the herring) produce in enormous quan-
tities eggs that are very minute and transparent, and
which float freely in the open sea. These are known as
“ pelagic,’ and the eggs of Cod, Haddock, Whiting and
their relations, and of Sole, Plaice, Flounder and other
related flat fish are of this kind. It is these pelagic eggs
of our most important food fishes that can be obtained in
millions at the spawning season and hatched artificially
in sea-fish hatcheries, and so may be kept and protected
during the first few days or weeks of their existence when
they would otherwise be exposed to innumerable enemies
in the surface waters of the ocean.
But it cannot be too emphatically stated, and widely
made known, that sea-fish hatcheries ought not to be
merely for the purpose of hatching young fish and then
setting them free in the sea. Hatching and Rearing of
fish is the end to have in view, and scientific men who
have charge of fish hatcheries will not be content till
they have succeeded in rearing into young fish, at a
reasonable cost, a large proportion of the fry which they
can now hatch from the eggs by the million. Professor
G. O. Sars first showed how the eggs of an edible fish
(the Cod) could be hatched in small numbers as a labora-
tory experiment; Dannevig in Norway and the U.S. Fish
Commission in America have devised the apparatus and
technique by which it has become possible with very slight
mortality to hatch out such eggs on an industrial scale
by hundreds of millions. The next advance must be in
rearing. At present practical difficulties block the way,
108 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
but the Fishery Board for Scotland has had some success
with Plaice, and the French at Concarneau with the Sole,
and we cannot doubt that further investigation and
experience will show us the best methods to pursue. It
is at institutions like this at Port Erin, where a Scientific
Laboratory is combined with the Hatchery, that experi-
ments in feeding and aeration can be carried out which
will eventually lead us to the successful rearing of the |
young fish that we now hatch and distribute as fry.
The Naturalist’s Dredge.
109
Report on the Investigations carried on during 1901 in
connection with the lULancasnire Sua - FIsHEries
Lagsoratory, at University College, Liverpool, and the
Sea-Fisa Hatrcuery at Piel, near Barrow.
Drawn up by Professor W. A. Herpman, F.R.S., Honorary
Director of the Scientific Work; assisted by Mr. ANDREW
Scott, Resident Fisheries Assistant at Piel; Mr. Jamrs
JOHNSTONE, B.Sc., Fisheries Assistant at Liverpool; and
Mr. Frank J. Cour, of University College, Liverpool.
With Eleven Plates.
CONTENTS.
1. Introduction and General Account of the Work ~ - =e LO
2. Sea-Fish Hatching at Piel - - : - - - 122
8. Note on the Physical and Chemical characters of our Sea
Waters - = = - : : = - - =i lS
4, Memoir on the Common Plaice - - = = SMe) ary
INTRODUCTION AND GENERAL ACCOUNT OF THE WORK.
Tue work of the past year has been chiefly :—
(1) The hatching operations and other similar work car-
ried out at Piel by Mr. Andrew Scott ;
(2) Laboratory investigations by Mr. Johnstone at Liver-
pool, chiefly this year upon the Plaice ;
(3) Some investigations upon the chemical and physical
characters of the sea-water of our district ;
(4) The work of the Circulating Fisheries Exhibition ; and
(5) The Practical Laboratory Classes for Fishermen.
Some of these matters which can be treated shortly I
shall remark upon here, the others will be discussed more
fully in the separate sections that follow.
We have aimed at having in each of these Annual
Reports, in addition to a short account of the work of the
K
110 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
year, some more detailed contribution of permanent value
to Fisheries Science. Thus, once we had the work:on the
Chemistry and Pathology of Oysters and other shell-fish,
and their connection with disease in man; once we had
the account of oyster culture on the West Coast of France ;
Mr. Johnstone in one report dealt with the reproduction of
the common mussel, and in another he gave us a very full
account of the cockle ; and last year the report contained a
detailed description of certain very important fish parasites.
This year we have what I suppose is the most complete
account of a single fish that has yet been produced. It is
a memoir on the common Plaice (Pleuronectes platessa), by
Mr. F. J. Cole, of University College, and Mr. James John-
stone. Mr. Cole and Mr. Johnstone have had this work in
hand for the last two years, and the pages and plates that
make up the greater part of this report represent an enor-
mous amount of labour both in the laboratory and the study.
The Plaice is one of our most important British fishes; it is
one of those local and sedentary forms in regard to which
our apprehensions may well be excited in view of the
marked increase of fishing power in recent years. It was
one of the fish to which the attention of the Parliamen-
tary Committees of 1893 and 1900 was specially given, and
in which all the Countries of Northern Europe are at
present interested because of the scheme for an International
Investigation of the North Sea. Under these circumstances
any contribution to our knowledge of the Plaice must be
especially welcome, and all knowledge it must be remem-
bered is of value, and helps us to understand the nature
and life of the fish in its manifold relations. For those
readers, however, who do not feel interested im the details
of structure, I may add that the Introduction, the discussion
of the nature and origin of the asymmetry, and the two
SEA-FISHERIES LABORATORY. Ver
sections of the Economic Appendix, will be found the most
readable and instructive parts. It is only fair to state
that the eleven beautiful plates that illustrate the Structure
and Life-history of the Plaice have been presented to us,
as the cost of their production has been defrayed by a
srant from Victoria University.
Mr. Scott’s account of the Sea-fish Hatching work at
Piel will be found on p. 122. During the past year the
work has been done upon the Flounder, and over 138
millions of young have been hatched and distributed in
suitable waters. Next year we hope to deal largely with
the Plaice, and a supply of spawners, obtained by our
steamer through the courtesy of the Fishery Board for
Scotland from Luce Bay, has already been laid in.
I desire to emphasise what I have pointed out before, that
sea-fish hatcheries ought not to be regarded as merely for
the purpose of hatching young fish and then setting them
free in the sea. The Hatching and Kearimg of fish is the
end to have in view, and scientific men who have charge of
Fish Hatcheries will not be content till they have succeeded
in rearing into young fish, at a reasonable cost, a
sufficiently large proportion of the fry which they can now
hatch from the eggs by the million. Professor G. O. Sars
first showed how the eggs of an edible fish (the Cod) could
be hatched in small numbers as a laboratory experiment.
Capt. Dannevig in Norway and the U.S. Fish Commission
in America have devised the apparatus and technique by
which it has become possible, with very slight mortality, to
hatch out such eggs on an industrial scale by hundreds
of millions. The next advance must be in rearing. . It may
be very useful to turn out large numbers of fry, but it is
not sufficient as an ultimate aim; what we want to do
ultimately is to hatch and rear fish. We must experiment
112 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
in the direction of how best to keep young fish alive at a
moderate cost, till they attain a fair size. At present
practical difficulties in feeding, and possibly in connection
with the movements of the water, block the way, but
Mr. H. Dannevig at the Hatchery of the Fishery Board
for Scotland has had some success with the Plaice, and
MM. Fabre-Domergue and Biétrix at Concarneau with
the Sole, and we can scarcely doubt that further investi-
gation and experience will show us the best methods to
pursue. It is at institutions like ours, where scientific
work is combined with the hatching, that experiments in
feeding and aeration can be carried out which will
eventually lead us to the successful rearing of the young
fish that we now hatch and distribute as fry. The rearing
of young Soles at Concarneau from the ege to a size of
35 mim., with a loss of only 50 per cent., is a striking and
encouraging fact.
The laboratory at Piel has been occupied by several
scientific workers during the year. In addition to Mr.
Scott, who has worked there throughout the year, Mr.
Johnstone has paid several visits, and Mr. Cole, from
University College, Liverpool, spent the greater part of
September at Piel working at the anatomy of the Plaice.
Dr. H. Lyster Jameson, from the Municipal Technical
College at Derby, worked in the laboratory for short periods
during the summer, carrying out some investigations con-
nected with the formation of pearls in marine shell-fish.
Mr. H. C. Chadwick, Curator of the Port Erin Biological
Station, spent a couple of weeks in March studying the
methods of sea-fish hatching.
Amongst the numerous visitors who came to see the ex-
hibition and the work going on in the establishment during
the year were tle following :—
SEA-FISHERIES LABORATORY. 113
_ Mr. Walter EH. Archer, Chief Inspector of Fisheries to the
Board of Trade.
Rev. R. B. Billinge, Furness Rural District Technical
Instruction Committee.
Rey. Dr. Hayman, Aldingham near Baicliff.
Rev. T. Fowler, Flookburgh.
Mr. F. J. Ramsden, Furness Railway Company.
Mr. A. Aslett,
Mr. F. Stileman, i . 5
The Mayor and Members of a Deputation from the Barrow
Free Public Library Committee.
Col. Turner and Members of the Stockport Corporation.
Mr. Fell (twice).
Mr. Ascroft (twice).
Mr. Houldsworth.
Professor Herdman (twice).
” 99 9
The Barrow Teachers, John Graham, B.Sc., P. H. Smith,
B.Se., and J. K. Turner, B.A., who worked in the laboratory
last year, were unable, through pressure of other duties, to
follow up their studies in the laboratory, but hope to be able
to resume them during the coming year.
The travelling Fisheries Exhibition, which was fitted up
in 1897, has during the last four years been on view in
puble institutions in the following Lancashire towns :—
Liverpool, Salford (1898), Preston (1898-99), Bolton (1899),
St. Helens (1900), Piel (1900-01), University College,
Liverpool (1899-1900), and finally Barrow (1901) where it
is at present.
This exhibition was transferred from St. Helens to Piel
in November, 1900. Various repairs to the jars and speci-
mens had to be made, and all the labels attached to the
former had to be renewed, owing to leakage of spirit from
114 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
some of the jars which had been damaged in transit. The
exhibit was thrown open to the inspection of the public
early in 1901, and, with the exception of the periods when
the classes for fishermen were being held, remained on view
until the beginning of September. During the time it was
at Piel the Barrow Town Council completed negotiations
for its removal to their town. The exhibit was removed to
Barrow early in September, and set up in the reference
room of the Free Public Library, where it will remain for
the ‘usual six months. .
The exhibit during its stay at Piel was visited by between
3,000 and 4,000 people, amongst whom were parties of
school children with their teachers from the Barrow
Schools. Everyone appeared much interested in the various
contents of the cases, and the majority went away with
more correct ideas and impressions of the work of the Sea
Fisheries Committee. The exhibit was of great service
during the time the classes for fishermen were held. The
specimens of the fishes, the food of fishes, and the prepara:
tions of shellfish, were removed from the cases and arranged
on the shelves of the laboratory, and referred to from time
to time to illustrate many points which were discussed
during the teaching of the men.
During the summer I gave evidence before the Royal
Commission on Sewage Disposal, as to the effects of sewage
and other materials in effluents upon fish and shellfish ;
and Mr. Scott has been able from time to time to make
certain experiments for me in the tanks at Piel upon this
question, which is of gieat practical importance in con-
nection with some of our estuarine and shore fisheries.
In regard to the Practical Classes for Fishermen which
had been started in Liverpool during the previous year,
three Courses of Instruction, the Third, Fourth and Fifth,
_ SEA-FISHERIES LABORATORY. ~~ 115
have been successfully carried on this year at. Piel, and
Messrs. Scott and Johnstone, who were mainly concerned
in the work report to me as follows :
“The Technical Instruction Commies of the coe
Council having given a further grant of money to enable
Fishermen to obtain instruction in the life histories, &c.,
of the Economic. Marine Animals, from our Scientific
Department, arrangements were made for carrying on the
Practical Classes at Piel, where a supply of living animals
could be obtained easily, and where, during spring, the
hatching of the eggs of Sea Fish could be shown.
“Three Classes, each attended by ten men, were nels
during the year, two in the Fish Hatching Season, and one
in the Summer. A Fourth Class, to follow immediately
after the third, was also proposed, but this was abandoned
owing to the difficulty the men had in coming at that time
of the year. The following are the dates when the
Classes were held, and the names of the men who attended
them :—
“March 18th to 29th—John Wright, Southport; William
Rimmer, Southport; Robert Wilson, Morecambe; David
Willacy, Morecambe; Richard Woodhouse, Morecambe ;
Daniel Hadwin, Flookburgh; Peter Butler, Flookburgh ;
Samuel Bayliff, Baycliff; John Shaw, Baycliff; Robert
Porter, Baycliff. —
“April 15th to 27th—William J. Robinson, Formby ;
Edward Rigby, Southport; Thomas Wright, Southport ;
J. Johnson, Banks; J. Wearing, Banks; Samuel Colley,
Sen., Fleetwood; Thomas Leadbetter, Fleetwood; Daniel
Bell, Morecambe; James Dobson, Morecambe; James
Swain, Morecambe. 3
“July Ist to July 12th—Thomas Hardman, Lytham ;
John Robert Wignall, Lytham; Richard Wright, Fleetwood:
116 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
William Fairclough, Fleetwood; Robert Butler, Flookburgh;
John Inman, Flookburgh ; Edward Robinson, Flookburgh ;
John Hadwin, Bardsea; John Hartley, Bardsea; Thomas |
Sumpton, Bardsea.
‘The classes were carried on by Mr. Johnstone, and the
work was on the same lines as in the laboratory classes
held at Liverpool (University College) in 1900*, each man, as
before, examining everything for himself. As much of the
material dealt with was supplied alive, the interest of the
men was greatly increased by being able to watch the
movements of the animals, in many cases through the
microscope. A further important point in having the classes
at Piel was the advantage of being able to practically
demonstrate to the men how to save and fertilize the ripe
eggs of fish, caught in the trawl, and to trace the develop-
ment of the embryo from the moment the egg was fertilised
until the young fish hatched out as a free-swimming larva.
The study of the developing fish formed part of each day's .
work in the case of the men who attended the first two
classes. ‘This was not possible at the third class owing
to the fish spawning season being over by the end of
May. ‘Two lantern demonstrations were given to each class
—one at the end of each week—and these were practically a
review of the work done on previous days. A special lantern
demonstration was given by Professor Herdman when he
visited the first class, and this was open to the local residents,
and was largely taken advantage of.
‘‘ At the conclusion of each course the senior member of
the class, spontaneously, on behalf of himself and the
other members of his class, expressed their indebtedness:
to the Technical Instruction Committee of ‘the County
Council, and the Sea Fisheries Committee. Some of the
* Vide Fish. Lab. Report for 1900.
SEA-FISHERIES LABORATORY. 117
men have also written long after returning to their homes,
expressing the pleasure they had had in the fortnight’s
work at Piel and their thanks for the practical instruction
they had been given and for the plain way in which things
were put before them.
“ There can be no doubt that these classes are of practical
value to the fishermen. All those who have been with us
freely admitted that many of the views they held regarding
the spawning, development, and rate of growth of fish and
other economic marine animals were erroneous. We are
convinced that it is only by allowing each man to study
the animals for himself, make dissections and examine
material with the microscope that lasting good can be
obtained. A course of instruction such as is given to the
fishermen would be of great help to the Bailiffs when
collecting specimens and tow-nettings for the Laboratories.
‘Various members of the Committee visited the classes
from time to time to see the progress of the work, including
Mr. Fell, Mr. Ascroft, Mr. Houldsworth, Mr. Dawson and
Professor Herdman, all of whom addressed the men on the
objects and work of the classes.”’
We had hoped this year to have hada report from Mr.
kh. L. Aseroft upon the tow-net gatherings taken throughout
the district. The scheme for the periodic collection of
gatherings from the surface of the sea at certain fixed
places was started in 1900, and during that year about 150
samples of material were examined by Mr. Ascrolt and the
results have been tabulated. During 1901 the work has
been carried on, and about the same number of gatherings
have been made, chiefly by Captain Wignall from the
steamer “John Fell,’ by Mr. Eccles in Liverpool Bay, and
by Mr. Wright in Barrow Channel and Morecambe Bay.
Many of these have been examined, but Mr. Ascroft’s recent
118 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
illness has unfortunately stopped—we hope only for a time
—this and other good work in connection with fisheries
investigations in which he was engaged.
The work that has been done of recent years by Scandi-
navian Hydrographers, and the attention that has been
directed to the matter by the International Conferences at
Stockholm and at Christiania, and the appointment by the
Board of Trade of an Ichthyological Research Committee,
all emphasize still further the point that I dealt with in
some detail in my last report, viz.:—the need for more
exact and detailed knowledge of our coastal waters and their
inhabitants. Such knowledge, both scientific and statistical,
can only be obtained by some such scheme as I outlined
last year, and by the use of a special steamer to supple-
ment the information that can be derived from commercial
trawlers. I have thought it important in the meantime to
have some samples of water from different parts of our
district examined as to their physical and chemical
characters by the most recent hydrographical methods and
by a competent chemist (1) with the object of noting what
variations exist in the Irish sea, and still more (2) with a
view of testing the methods as to their relative importance
and practicability for future schemes of work at sea.
Mr. Alfred Holt, Junr., B.A., (Cantab.), has kindly under-
taken this work, and during the last three months has been
examining samples of sea-water in my laboratory. I am
glad to have from him the report which is printed at p. 128.
At the Eleventh Annual Meeting of Representatives of
Fisheries Authorities at the Board of Trade in June, 1901,
the President, the Right Honourable Gerald Balfour, M.P.,
made some interesting observations bearing upon fisheries
research which must carry weight, and, it is to be hoped,
will receive the attention which they deserve. Speaking
SEA-FISHERIES LABORATORY. 119
of the lamented death of Sir Courtenay Boyle, he referred
to communications between them on the subject of the
best means of “ improving and following up that scientific
research into the life and habits of fish, the practical
importance of which is coming to be more and more
recognised.”” Then, in referring to the Report of the Select
Committee on the last Immature Fish Bill, he said, ‘‘ It
came to the conclusion that it would not be expedient to
press forward the Bill in the absence of further information.
It fully recognised the danger we were running of having
our seas depleted of fish. It further recognised that one
cause of such depletion was the capture and destruction of
small, immature fish.’ And then he went on to point out
the recommendations of that Committee, which were briefly
(1) the international regulation of the North Sea, and (2)
the effective pursuit of scientific investigation, and said
‘In the face of the conclusions arrived at by the Select
Committee and of those recommendations, I think it is
absolutely essential now that we should proceed upon the
jines indicated by them before attempting any further
legislation.” He then referred to the action of the Govern-
ment in international negotiations, with the view of arriv-
ing at some agreement as to protected areas, which has not
yet resulted in any definite conclusions; and proceeded as
follows :—
“Next with regard to scientific investigation of the life
and habits of fishes. The Board of Trade are at the
present time arranging for a Departmental Committee, of
which Sir Herbert Maxwell has undertaken to be Chairman,
with the following reference which I will read out. ‘To
inquire and report as to the best means by which the State
or Local Authorities can assist scientific research, as
applied to problems affecting the fisheries of Great
120 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
Britain and Ireland, and in particular whether the object
in view will be best attained by the creation of one
central body or department acting for England, Scotland
and Ireland, or by means of separate departments or
agencies in each of the three countries.’ You will see,
gentlemen, that that is a very wide reference, and I trust
that the deliberations of this Committee, which is now in
course of appointment, will end in some fruitful result.”
So far the President of the Board of Trade, and I think
all who are interested in the advancement of knowledge and
the promotion of fisheries research will agree as to the 1m-
portance of the announcement; but as I have had the
honour of being appointed a member of Sir Herbert Max-
well’s Committee on Ichthyological Research, it would be
highly improper for me to make any comments upon the
work that will be necessary in order to carry out Mr.
Balfour's suggestions, or upon the results that are likely to
follow. But quite apart from the Board of Trade Com-
mittee, it 7s important that I should urge upon Lancashire
my conviction that our local waters of the [Irish Sea ought
to be investigated under the auspices of our local Cominittee.
Whether or not a great national or international scheme of
investigation be entered upon, it is most desirable that
Laneashire, which has obtained credit for an advanced and
enlightened policy in the past, should recognise its obliga-
tions—moral if not legal—and should carry out an adequate
programme of work at sea on similar lines to that of the
Scottish Fishery Board to the North of us, and to that of
the Irish Board on our West. The Fisheries Branch of the
Irish Department of Agriculture has now an _ organised
scientific department, with a well known marine biologist,
Mr. Ernest Holt, as scientific adviser, and an efficient
steamer, ‘‘ The Helga,’ measuring 150 feet in length, which
SEA-FISHERIES LABORATORY. 121
is now working from Dublin as a centre in the Western
part of our own area. If this could be supplemented by a
Lancashire steamer devoted wholly to statistical and scien-
tific work, the two working on a common programme, there
would be a fair prospect that this the most definitely cir-
cumseribed of the British seas * would be adequately in-
vestigated. Itis only now a question of expense. Sufficient
preliminary investigations have been made, we know exactly
what we want to do, and the Irish steamer is now at work.
All that is required is an additional steamer for scientific
work in the Lancashire District and funds to carry out
the scientific programme. In previous reports | have
shown the suitability of the Irish Sea for such work, and
I am interested to see that Dr. Johan Hjort, in a recent
publicationt expresses a somewhat similar opimion in
regard to some of the local sea-areas on the Norwegian
Coast as compared with the North Sea. He says:—‘‘ We
consider that the conditions affecting those srall localities
on our Coast are exceptionally synoptic, and far easier to
crasp than those of the exceptionally complicated and vast
territory of the North Sea, in which the Plaice lives.”
Finally, I should, perhaps, explain here (1) that my
approaching departure for Ceylon, to carry out an
investigation on the Pear] Oyster fishery for the Govern-
ment, has necessitated the issue of the present report a
few weeks earlier than usual, and (2) that although all the
manuscript and the first proofs have passed through my
hands, I have had to leave Mr. Jolinstone to read the
pages for the press.
W. A. Herpman.
Untverstry Couuecr, LivERPoou.
December, 1901.
* The Irish Sea contains about 10,000 square miles, and is about one-
twentieth part of the size of the North Sea.
+Report on Norwegian Fishery and Marine Investigations, Vol. I.,
p. 152; Kristiania, 1900,
122 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
THe Fish Hatrcuery at Pret.
By AnpRew Scort.
In the operations carried on in the hatching season of
1901 only the eggs of the white fluke or flounder (Plewronectes
flesus) were dealt with.
The flounder is a fish which is fairly plentiful in the in-
shore waters of our coast, and with the Plaice. forms the
greater bulk of the fishes taken in the stake nets, especially
in the northern part of the Lancashire area. It is therefore
of considerable money value to the stake net fishermen, as
well as to the small sailing trawlers that fish in the channels
of the various estuaries in the district. Although not held
in high esteem as an article of food by the fishermen them-
selves, the white fluke finds a ready sale in the inland towns.
The fishermen look upon the white fluke with a certain
amount of disrespect, and have applied various uncompli-
mentary namestothisfish. This 1s owing tothe questionable
grounds which it frequents at particular times of the year.
It is said to be more abundant, especially during the
summer months, in areas affected by the discharge of sewage ~
from large towns, than in clean sea water. Thisis true to a
certain extent, but the fish does not frequent sewer outlets
merely for the sake of any food that may be brought
down. It is, more than anvthing, because of the low specific
gravity of the contaminated area, due to the great quantity
of fresh water which finds its way along sewers, that
the flounder frequents such localities. The flounder is
essentially a brackish water fish, and is known to ascend
far up rivers in summer. In some parts of the country it
is known as the fresh water fluke, and is not uncommon in
Jakes which have an unobstructed connection with the sea,
SEA-FISHERIES LABORATORY. 123
On the approach of cold weather the fish migrate towards
the sea. The majority of the sexually mature forms in
time make their way out to sea tospawn. The movements
of the immature flounders are greatly influenced by the
conditions of the weather. When there is littJe or no frost
they remain in the shallows of the estuaries. When frost
of any severity sets in they quickly disappear into the
deeper channels. It mild winters it is probable that even
some of the sexually mature fish remain in the deeper parts
of the channels and spawn there in the spring It is nota
rare thing to find nearly ripe fish and occasionally partly
spent ones in Barrow Channel in February, when the
weather has been favourable.
The food found in the stomachs of flounders varies con-
siderably. Sometimes it is mollusca such as young
mussels ; at other times we find only crustacea, Mysis and
Corophium, and occasionally marine worms.
The incubation of the eggs of the Flounder has formed
the principal part of our hatching work hitherto, for two
reasons: (1) Mature Fish are easily collected in Barrow
Channel during the latter part of the year; and (2) little
difficulty is experienced in transferring them to our tanks
and in keeping them in captivity. |
In future, however, we propose to devote more attention
to the incubation of Plaice eggs, and have already secured
a supply of mature fish for next (1902) season.
Mature Plaice are not plentiful in the Lancashire waters,
and after a week’s search, by the steamer, in the middle of
November, only five were captured. Luce Bay, in the
South of Scotland, was then suggested. This area was
well known in former days for its large Plaice, and was
fished with success by Fleetwood Sailing Trawlers, before
124 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
it was closed against trawling by the Fishing Board for
Scotland. Permission was courteously given by that
Board for our Fisheries Steamer to trawl in the Bay. It
was late in the year for such in-shore waters, when we
made our visit, yet a good number of mature Plaice were
secured in a single day's trawling. The weather was
favourable for the passage to Piel. After a run of nearly
nine hours the fish were landed in good condition and
placed in our tanks. The fact that we have to go to closed
waters for our spawning fish, is a good proof that protected
grounds, in which all trawling is prohibited, are undoubtedly
a benefit to the fisheries. They are the means of preserving
the maturing fish, and so of ensuring that at least some
fish will be left to spawn. With no protection, and the
improved methods for catching fish that are now employed,
the adult fish, especially of sedentary species like the
Plaice, would soon be as scarce as they now are in the
Trish Sea between Lancashire and the Isle of Man, where
they were formerly plentiful.
During the hatching season of 1901 we had upwards of
250 flounders in the tanks. The ratio of sexes, as far as
could be judged by size, was three females to two males.
The males of flat fishes are, as a rule, smaller than the
females; but there is no certain guide from external appear-
ances unless the fish are ready to shed the reproductive
elements. The females are then recognisable by the very
swollen abdomen. Consequently there are usually a num-—
ber of fish amongst the stock that do not reproduce owing
to immaturity. These cannot be detected when the fish.
are collected. ‘The fish were collected in Barrow Channel
by Mr. Wright, as in former years, and kept in tanks till
the spawning season was over, when they were set free,
SEA-FISHERIES LABORATORY. 125
Throughout the whole period the fish were in the tanks
they were fed on lug worm (Arenicola), which is plentiful
in the vicinity of the hatchery. Mussels with the shells
removed were tried at first, but were not eaten by the fish,
and were discontinued after a few days.
The first fertilised eggs were collected on February 28th.
From that date onwards the numbers gradually increased,
‘until the maximum was reached in April. After that the
numbers rapidly decreased, and the spawning was over by
May 10th. During the spawning period nearly fifteen and
a half millions of eggs were collected and placed in the
boxes for incubation. ‘These eggs produced over thirteen
and a half millions of fry, which were set free about the
centre of Morecambe Bay. The period of incubation varied
from eleven days at the beginning to six days at the end of
the season—a reduction of time entirely due to the in-
creasing temperature of the sea water, which is shown by
the table of temperatures and specific gravities given below.
It will be noticed from the table that the specific gravity
during the hatching was satisfactory, and never fell below
1:026 till after the middle of May. The loss of eggs during
incubation from all causes averaged about 11°5 per cent.,
practically the same as last year. A number of attempts
were made to rear flounder larve, but these experiments
failed owing to the difficulty of getting minute natural food
in the waters of the channel.
The following tables show the numbers of eggs collected
and fry set free, and also the specific gravity* and tempera-
ture of the water during the spawning season.
*The figures given are simply the uncorrected readings taken with the
Kiel areometers.
L
126 TRANSACTIONS LIVERPOOL
Eggs Collected.
BIOLOGICAL
Fry set free.
SOCIETY.
Feb. 28 235,500 ~~ - 210,900 March 13
March 4 571,000 : 432,000 em
i 2500). 930,800 es
BR dated] LS00dia tie 416,300 >See
14 392,700 - 349,000 April 1
fSpst AT LOOM. ais 428,000 _,, 1
F6.r B58 000m giz 318,600 1
25 595,500 529,900 9
» 28 614,000 545,000 9
gist 296 yor TOMO hee 702,400 9
April. fal e9985,000 - 876,400 16
5 Sih G28, OU Ory chet 736,700 16
i) 9h6 SALOON MODAL +: 887,000 16
Gs 90000034 += 800;000:. sym
Kid? mx OPRO00" Law 825,000-. 5, 22
pt hing KOOOONG: see 888,000 ,, 26
ey 18/5 4800,0008d" 711,800.) ¢ a ee
11199 «te OOOO »eae 887,500 May 1
1 26. :800,000° .~ 711,900 .° (a
4 20's 1 31S40/000- face 747,400 |. “oan
May 38 600,000 - 533,600 ,, 10
oe baedilis< gO UNG, ae 445,000 .; ame
fel Oi x OOOO Oar fis: 444,800 ,, 20
15,430,300 13,658,000
All the Fry were set free by Mr. Wright, the Chief Bailiff,
from his boat, between Walney and Morecambe Bay Ship.
SEA-FISHERIES LABORATORY. 127
TABLE showing Temperature and Specific Gravity of the sea
water pumped into the store tanks each day during the
spawning season.
=
Date. | Temperature ces Date. | Temperature ae
Feb. 4 42°C 1:0264 Mar.29 3°6° C 1:0268
3) Sikes a 10262 30 Ae 1-0264
6 3°6° ,, 1:0262 31 oO, 1:0268
fh 2) Ome 10264 April 1 D2 5 10266
8 4°2° ,, 1:0264 2 Does 1:0266
9 43° 5, 1:0264 3 ON Sayan 1:0264
10 4-8° ,, 10264 4 Silos 1:0262
ial Bee 1:0264 9) 54° ,, 1:0262
12 BOs, 10264 6 5:4° ,, 1:0264
13 SROr 5 1:0264 7 Gin, 10264
14 DEO, 1-0264 8 Gee 10264
15 a0” 1:0264 9 6°40 ,, 1-0262
16 a0 35 1-0264 10 GrOes, 1-0262
ay, Brae 55 1:0264 11 (GAs 1°0262
18 ele 45 1:0264 12 rho 1:0262
iy obo; 1:0266 13 di 1:0260
20 i ee 1-0266 14 Qe. 10260
21 ee 1:0266 15 6°4° ,, 10260
22 4-4° ,, 1:0266 16 Grhics 1:0260
23 AO), 1:0264 17 HEOo », 10260
24 BO: 5, 10268 18 HOe «5 10260
25 0A Sane 10268. * 19 CAS 1:0260
26 aS. 1-0267 20 ia os, 1:0260
27 Dib 43 1:0267 21 SOs: 10260
28 D075; 1:0267 22 rare: 1:0260
hae aT 54° ,, 1:0268 23 84° ,, 10260
2 5:4° ,, 1:0270 24 Oras 1-0260
3 Cee 1:0268 25 Sion 1:0260
+ o> 4, 1:0268 26 SOR A 1:0260
5 DA, 1:0264 27 8:4° ,, 1-0262
6 Bere, 1:0264 28 ‘Sabre 1-0262
it Dea), 1:0262 29 Sree 1-0262
8 OPDr §, 10262 30 Saat. 1-0262
9 Se ee 1:0262 May 1 Oa 10260
10 oO", 1:0262 2 i oe ee 1:0260
a BOs 1:0262 3 Ea 1:0260
12 ot, 1-02€2 4 SHS Sr 1:0260
13 Br?) 5 10262 5 OBS. 1:0260
14 Oa. ., 10262 6 Soap 1:0260
15 66°, 10262 it O80 3, 1:0260
16 Or 5, 1:0262 8 OSes 1-:0260
17 JO 5, 1:0262 9 HOO 1:0260
18 2 oman 1-0262 10 10°4° ,, 1:0260
19 a0>7,, 1:0262 ach 10:6", 1:0260
20 4°4° ,, . 1:0262 12 10:87 ,; 1:0260
21 ae 1:0262 13 TOFS 1:0260
22 AO y5 1:0264 14 EDs, 5 1:0260
23 DOL. 5; 1:0266 15 a 1:0260
24 w0r";, 10266 16 ba re 1:0260
25 4:4° ,, 1:0266 17 18? 1:0260
26 BOE 5, 1:0268 18 1220" 55 1:0260
27 4:4° ,, 1:0268 19 12°2° ,, 10258
28 Oe 59 1:0268
128 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
THe DETERMINATION OF SOME PHYSICAL AND CHEMICAL
CHARACTERS OF SOME SAMPLES oF WATER FROM THE
IrisH SEA.
By Aurrep Hout, Jun., B.A. (Cantas.)
Having been requested by Prof. Herdman to examine for
him some of the physical and chemical characters of the
water of the Irish Sea, with a view to selecting the most
practical and effective methods for their rapid determina-
tion, I obtained a number of samples from different places,
and estimated. as far as time allowed, the specific
gravity, colour, chlorine, total salinity, alkalinity, carbonic
acid gas in solution, and the lime.
The ratios between these were then determined, in order
to see if they were sufficiently constant to enable one to
calculate from an accurate. determination of one character
the values of the others.
At the same time it was hoped that some knowledge of
the movements of the water of the Irish Sea area might be
obtained from examination of the values obtained. This
will be discussed at the end of this paper. Though every
care has been taken to obtain accuracy, the fact that I had
not always at my disposal a sufficiently accurate balance
forced me to use in the titrations known volumes of solu-
tions instead of known weights of them, which undoubtedly
may cause error. Further, for the same reason, some pro- —
cesses had to be done volumetrically instead of gravimetric- _
ally, which though easier to perform do not produce quite
such good results,
—
M
= <3
SEA-FISHERIES LABORATORY. 129
Very little hydrographical work seems to have been done
in the Irish Sea, though the Clyde sea-area immediately to |
the north of it has received much attention; in fact almost
the only analyses of the water seem to be those done by
Thorpe and Morton in 1870 (J. C. S. xxiv. p. 506), so there
is little past work to comment on.
The working here described has been done mainly by. the
methods employed by Dittmar, Knudsen, Jacobson, &c., and
the working out of many of the results has been performed
with the assistance of Knudsen’s Hydrographical Tables.
The values obtained are given in considerable detail,
which it is hoped may be of some value as showing the
degree of accuracy obtained by different methods.
1.—COLLECTION OF THE SPECIMENS.
These were obtained mainly from the Biological Stations
and from our fisheries steamer, but not on any regular ex-
pedition. For this reason I have not yet been able to obtain
specimens from several desirable places, nor to obtain in all
cases the temperature of the water at the time of collection ;
further, the specimens are all of surface water, as a Mill’s
water bottle which was ordered did not arrive early enough
to be of use. I hope to use it in a further investigation on
a future occasion. The samples consisted each of about a
litre and a half of water, and were kept in glass bottles with
ground glass stoppers till used in the laboratory. This
method has the disadvantage of slightly increasing the
alkalinity owing to the action of the water on the glass, but
this increase is probably very slight since it was seldom
~ that the water was kept more than two or three days before
being used for the determination of this character.
180 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
9.—DETERMINATION OF THE SPECIFIC GRAVITY.
The specific gravity of the water at 17°5° C. (9 17°5) was
determined by means of areometers made by Stegel at Kiel,
a salinometer of Hicks, and in a few cases by a hydrometer
of Negretti and Zambra.
Several observations were made with the Kiel areometers ©
at different temperatures, and these values were then cor-
rected for temperature and the glass of the instrument by
means of Knudsen’s Hydrographical Tables.
The temperature of the water at the time of the observa-
tions was observed by means of a thermometer made by
Stegel of Kiel, and graduated to 0°2° C. .
By means of these determinations at different tempera-
tures it was hoped that some of the errors due to a single
observation would be avoided. The Negretti and Zambra
hydrometer was a small pocket instrument, and it is remark-
able how good are the values obtained by it, but at the same
time it must be noted that all values obtained with it are
about 0°0014 too low. This presumably is due to the scale
not being accurately placed in the stem.
The values of the Kiel areometers are given to five decimal
- places, but the last place is obtained in the correction above
mentioned, and is not read on the instrument except in a
very few cases.
In the annexed table the values obtained with these in-
struments are given, and also, for comparison, that calculated
from the chlorine value. In the case of the areometer read-
ings the maximum and minimum are given so as to show
the error between the readings at different temperatures. ~
The density of the water at 0° C. referred to distilled
water at 4° C. was calculated from the above figures, and is
given in the tables at the end of the paper.
=~]
8.
. Blackpool
SEA-FISHERIES
LABORATORY.
Sprciric GRAVITY TABLE.
LOCALITY.
. Landing Stage (High
Water)
steeper ccscericcce
. Landing Stage (Low
Water)
New Srishton .........
. Crosby Channel (1 hour
CCG) Sah ee
. 1 Mile N. of Bar Ship
(Low Water)............
i i a iy
. Piel (Barrow Channel)
Port Hrin (High Water)
. Port Erin (Low Water)
. Fleshwick(High Water)
. Douglas Bay (Low
Water)
Ce
> 15 Miles S.E.. of
BOWES oe. cece secnesee
. 30 Miles S.E. of
INA ces eies.seeaces
| 45 Miles §.E. of
MOVES 55 eccesssacsenes
5. Near N.W. Light Ship
ey. tient Ship ......
. 2 Miles W. of N.W.
(Clo)
. 24 Miles N.W., 4 W.
of Walney Light ......
9. 10 Miles N.W. by N. 4
N. from Point of Ayre
Light Ship, I.0.M. ...
Sp. Gr. at 17°5
according to Kiel
Areometers.
(1.02312
| 1.02313
(1.01629
( 1.01631
(1.02476
( 1.02478
(1.02334
( 1.02337
(1.02527
{1.02538
1.02388
1.02390
{
(
(1.02516
(1.02517
(1.02584
(1.02585
(
(
1.02588
1.02582
(1.02594
( 1.02594
(1.02568
(1.02572 -
(1.02601
| 1.02603
( 1.02606
| 1.02610
(1.02587
| 1.02591
(1.02441
( 1.02447
(1.02543
| 1.02544
{1.02546
( 1.02546
(1.02549
(1.02551
(1.02575
( 1.02576
Maximum and
Minimum Readings
Difference between
of Kiel Areometers
0-00001
0-00002
0-00002
0-00003
0-00011
0-00002
0-00001
0-00001
0-00006
nil
0)-00004
0:00002
0-00004
0-00004
0-00006
0-00001
nil.
0:00002
0-00001
Sp. Gr. at 17°5
according to Hicks’
Salinometer.
H
e)
iw)
iS)
bo
1:0260
1:0259
1:0259
1:0257
1-0261
1:0259
1:0244
1:0253
1:0252
1:025
1:0258
Sp. Gr. at 17°5
according to Hydro.
meter of Negretti
and Zambra.
1:0239
1-0226
1°0245
1:0245
1:0245
1-0230
131
calculated from
Chlorine
Values
Sp. Gr. at 17°5
1:02315
1-01632
1:02466
1:02333
1-02529
1:02387
1:02520
1:02584
1:02587
1:02593
1:02571
1:02602
1-02608
1:02589
1:02441
1:02546
1:02546
1:02549
1:02576
182 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
3.—CoLOoUR OF THE WATER.
‘This is an unimportant character, but it was fourd to vary
so much that it seemed useful to note it.
The colour was observed by looking down a column of
water about 20 inches high on to a brightly illuminated
white surface. The words used to denote the colour are,
it is hoped, not too vague.
Colour.
1. Landing Stage (high water) - greenish erey.
2. Landing Stage (low water) - greenish orange.
3. New Brighton” - - - greenish brown.
4. Crosby Channel (1 hour
flood) - - - - pale olive green.
5. 1 mile N. of Bar ship (low
water) - - - - yellowish green.
6. Blackpool = - - - - greenish grey.
7. Piel (Barrow Channel) - - greenish grey.
8. Port Erin (high water) - - bluish green.
9. Port Erin (low water) - - pale grey.
10. Fleshwick (high water) - - bluish grey.
11. Douglas Bay (low water) - greenish grey.
12. 15 miles 8.E. of Douglas = -_ greenish blue.
13. 30 miles 8.E. of Douglas - pale bluish green.
14. 45 miles 8... of Douglas - greenish grey.
15. Near N.W. light ship - - pale olive green.
16. N.W. light ship - - bright yellow green.
17. 2 miles W. of N.W. light
ship - - - - - grey green.
18. 24 miles N.W. 4 W. of Wal-
ney light - . - - greenish grey
19. 10 miles N.W. by N. 3 N. from
Poimt of Ayre light house,
I.0.M. - - - - grey green
SEA-FISHERIES LABORATORY. 138
- 4,—SuspenpED MatTTER.
This was not estimated owing to the difficulty of filtering
large volumes of water, and of weighing small amounts of
ash. It was very abundant in the Mersey water at low
tide, but not nearly so abundant at high tide. There
Was quite an appreciable amount of suspended material
in all samples off the Lancashire coast, but in the open
sea, and round the Isle of Man, the water is practically
clear.
For the determination of the specific gravity and other
characters, the sediment was allowed to settle and the
clear water decanted off.
5.—EHstTIMATION OF THE CHLORINE.
This was done with the greatest possible accuracy, both
by Volhard’s method and also by titration with standard
silver nitrate solution, using potassium chromate as
indicator.
The exact process by each method is given and also the
results, for the sake of comparison.
(a..—PREPARATION OF SOLUTIONS.
The silver nitrate solution was prepared by
dissolving the pure fused salt in sufficient water to
make about a decinormal solution. This could then
be diluted to any desired extent.
It was standardised by titration against the sodium
chloride solution (which see), using potassium
chromate as indicator, and also by Volhard’s method
It was restandardised about once a week, in order to be
certain as to its exact strength from time to time.
The sodinm chloride solution was prepared by dis-
solving an accurately determined weight of pure, dry
134
(b
-TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
sodium chloride in a known volume of distilled water.
The sodium chloride was obtained from the ordinary
crude salt by precipitation from a strong aqueous
solution by means of hydrochloric acid. The precipi-
tate was filtered, dried, and finally fused. The actual
strength of the salt solution prepared was nearly <5,
and this could then be diluted as required.
The ammonium sulphocyanide solution was prepared
by dissolving the pure salt in water in such proportions
as to make it approximately decinormal. Its actual
strength was not determined as it was titrated against
the silver nitrate solution only to find the ratio between
their strengths.
Saturated solutions of the two indicators—potassium
chromate and iron alum—were employed, one drop
being sufficient for each titration.
.)—VouHarp’s Merton.
A sample of sea water (about 10°0 cc.) was titrated
as a preliminary, in order to find about the amount of
silver solution required.
The accurate determinations were then done in the
following way :—
10cc. of the sea water was measured from a pipette
into a beaker, and mixed with a little distilled water.
About 2cc. more silver solution was then added than
the preliminary examination had shown to be neces-
sary. The mixture was thoroughly shaken and allowed
to settle, and the nearly clear supernatent liquid was
filtered. The residue in the beaker was twice washed
with distilled water, and the washings were mixed with
the filtrate after they themselves had also been filtered.
All the excess of silver was now found to be in the
SEA-FISHERIES LABORATORY. 135
filtrate. It is to be regretted that the filtering could
not have been done through a Gooch filter, as then the
precipitated silver haloid could have been collected and
weighed, and so would have formed an additional check
on the values obtained by titrating the filtrate.
This filtrate was poured into a porcelain dish, a
drop of iron alum solution added, and titrated drop by
drop with the sulpho-cyanide solution till a red colour
appeared. ‘To this was then added enough silver
nitrate solution to just destroy the colour, and this
process of alternately titrating with the sulpho-cyanide
and the silver solution was irequently repeated in a
zigzag manner till a great number of determinations
of the end point were obtained, the mean of which was
considered accurate.
(c..—Usine Potasstum CHRomatTE as INDICATOR.
As in the previous case a sample of about 10ce. of
the water was first titrated to find about how much
silver solution was required.
In the accurate determinations 10cc. of the sea water
were mixed with some distilled water in a beaker, and
then about 0°5ce. less silver solution than was required
for complete precipitation was added. The mixture
was well mixed and a drop of the chromate solution
added, and then the silver solution was run in drop by
drop till a permanent change of colour was obtained.
The end poimt was obtained repeatedly by zigzag
titrations with the salt and silver nitrate solutions.
A mean of the values obtained was taken as correct.
Considerable errors occur in both methods, but more
especially in this, owing to the difficulty of obtaining a
standard of colour which represents the end of the
reaction.
136
TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
In order to get as much accuracy as possible, a —
sample solution coloured by chromate was used, and
the end point was considered to have been reached as
soon as the tint of the solution being titrated differed
permanently from this sample.
CHLORINE TABLE.
3 A ‘i is n rs
Ao Arm. | 8a3
£423) $88 | 82 ans
Soa | 648 | .ode
euge |) g>3 | se.”
Bad | Bh | ase
3-4 O ae iS,
> >
Landing Stage (High water).................. 16°84 16°79 16°76
Landing Stage (Low water).................. 11°82 11°81 11-80
New Brighton, cc n.eon ue .cscae Oe ee ideal 17°94 17°87 17°95
Crosby Channel (1 hour flood)............... 17°03 | 16°95) Gee
1 mile N. of Bar Ship (Low water)......... 18°38 | 18:33 | 18°32
BlaSk oak Gas «srs chacGiash des caieon Saonbetgoni dad 17-28 |) 17:30) sian
Piel (Garrow /Chanmellr . 135... enc t sei. cone 18°32 18:26 | 18:24
Bort: nun Eliot water) Jac, eoaecean tecsnee re? 18°72 18°73 18°73
Pory fiaciun: (ow weaten):; ceincee- <<< ses care 18-77 | 18°7o0 nee
Fleshwick (High water) .......0.cc0c00 18:85 | 18-79 | 18-80
Douglas Bay (Low water).................660 18°64 18-63 18°63
Lo.aailes SH Of Deum basi acaals dass ya ae ahee 18:90 | 18°86 18°85
30:miles 8:5. ‘of Douglas ...16.2icd see. aee 18°95 18°90 18°89
45 miles 'S.E.. of Douglas. .i2.cc ccs ceaseess 18°80 | 18°76.) eae
Néar oN. We duisht Shipins.cnescd,<ctecomsane 17-65 | 18°69 ie
N.W. Light Ship .........0-.:seseeeeererese | 1842 | 18°45 | 18-43
Fmiles W. of N.W. Light Ship ......ccss0 18°46 | 18°45 | 18°45
24 miles N.W. + W. of Walney Light..... 18°48 18°47 18°47
10 miles N.W. by N. 4 N. from Point of
Ayre Light House; T.0.M.......<cawesess 18°65 18°67 18°66
SEA-FISHERIES LABORATORY 137
6-—ALKALINITY.
The determination of this character gave me a great
deal of difficulty.
Two methods were adopted :—One, by titrating in the
cold with standard acid in the presence of an indicator
unaffected by carbonic acid ; the other, by adding a known
volume of acid, boiling off the carbonic acid, and estimating
the excess of acid by titration with standard alkali.
By neither method could really accurate results be
obtained, owing to the difficulty of finding an indicator
which would give a sharp end point in such a dilute
solution as sea water.
Various indicators were employed — methyl orange
phenolphthalein, and aurine—but constant end points could
not be obtained.
Kach method will now be considered separately.
(a..—Direct TITRATION.
100 ce. of the water was mixed with just enough 1
per cent. solution of methyl orange to have a percep-
tible colour, and standard sulphuric acid (about -3,) was
run in till a distinct pink colour was produced. This
was then titrated back with standard alkali (KOH),
and so by a series of zigzag titrations a number of
end points were obtained. Unfortunately these were
by no means uniform, as each was a trifle higher than
the last, so that at the end of about ten end point
determinations by this method the amount of sulphuric
acid required was found to have increased about 1°0 ee.
I did not continue after this point as the value was be-
coming absurdly high; indeed, I think the first end
point must be more nearly correct than any sub-
sequent one.
138 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
Of course phenolphthalein could not be employed as
an indicator in this case as it is attacked by carbonic
acid.
The values given by this method are what seem to be
most probably correct from titrations with several
different portions of the sea waters. The titrated
solution was found to become alkaline again on
standing for some time, hence the imperfect results
of this method.
(b.).—By Estimation oF Excess or Actp (Tornoe’s
method)*
Whilst the former method seemed to give too high
results, this method when phenolphthalein was em-
ployed as indicator, seemed to err on the side of
lowness, which was probably due to the carbonic acid
not being completely driven off by boiling.
100 ce. of sea water were boiled for about twenty
minutes with excess of standard sulphuric acid (about
==5)- Most other workers so far as I have been able to
find out seem usually to have employed hydrochloric
instead of sulphuric acid, but this latter seemed to me
to possess a great advantage over the former in that
there is practically no lability of the acid itself being
carried away in the steam. Even in very dilute solu-
tion hydrochloric acid is always more susceptible to loss
in this way on boiling than is sulphuric. Sulphuric
acid may have the disadvantage of being dibasic and so
forming two series of salts, whereby the excess of acid
might not be a direct measure of the alkalinity owing
to the formation in unknowh proportions of acid and
normal salts, but as the base with which the carbonic
acid in sea water is almost all combined is lime, this
danger seemed to be almost completely done away with.
*Den Norske Nordhaus-Expedition, 1876-1878, Chemi. Christiania.
bt te A ee
SEA-FISHERIES LABORATORY. 139
When the boiling was finished, a drop of the
phenolphthalein, aurine, or methyl orange solution
was added, and the excess of acid was titrated with
standard alkali (KOH). Several end points were deter-
mined by zigzag titrations with standard sulphuric
acid and alkali, and the mean of the values obtained
was considered to be correct.
The values differed from those obtained by the first
method, but as by using aurine as indicator very ac-
curate and close results were obtained, these were taken
as representing the true value of the alkalinity. This
was confirmed by a test case performed in an exactly
similar manner, only using standard sodium carbonate
solution instead of sea water.
The values obtained by this method always coincided
with one of the many end points determined by direct
titration, but as this was not always the first, that
method may be considered as nearly valueless for
accurate determinations.
As to choice of indicators it was found that aurine
gave far more accurate results than any of the others,
but phenolphthalein was nearly as good. Methyl
orange was on the whole unsatisfactory.
Of course no estimation of the alkalinity by any of
these methods is really accurate, as the amount in the
water is perpetually changing owing to the following
causes :—(t) action of the sea water on the glass of the
bottles in which it was stored; (i) difference in tem-
perature between the water when used in the laboratory
and when first collected, causing loss of carbonic acid ;
(wt) action of microscopic animals in tlie water till
their death.
140
£8.
12.
TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
This method, further, does not estimate the carbonic
acid dissolved in the water as such, so in a very few
cases an attempt was made to estimate this by the
method about to be described. The results are given
in the general table at
the end.
ALKALINITY TaBLE.
Values in mgs.
Values in mgs.
Difference in
mgs. per litre
fate per litre between max-
LOCALITY. obtained by | Obtained by jimum and min-
direct titration pape a ‘i byiPom ree
method.
. Landing Stage (High Water) 57°48 56°12 0-08
. Landing Stage (Low Water) 51°11 48°38 0-10
ENON TIGMGON © occ cccpcecseseese 57°48 58°14 0-16
. Crosby Channel.....ccseseeseeee 55°50 55°32 0:08
. dmuilewN. of Bar Shap s-.2../.: 54:29 - 53°30 0-08
Black MOOk ago casaeeass Jeo aeeatonss 53°04 50°90 0 01
PeGh cine since’ napbiraa ae omasiiadacs 53°04 50°88 0-12
. Port Erin (High Water) ...... 54:97 53°64 0-05
. Port Erin (Low Water) ...... 53°02 51°76 0-09
CSS Wale titted cate ct bie Saeea tes 53°04 50°88 0-08
J Woplas Bay vice. celtscc cen ceces 54°30 54°60 0-09
. 15 miles 8.E. of Douglas...... 52°34 54:86 0°12
. 30 miles S.E. of Douglas...... 54°30 55°44 0-10
. 45 miles S.E. of Douglas...... 55°47 55°28 0-09
. Near N.W. Light Ship ...... 54°30 53°30 0°10
eel TN el Gr fed ci rays 11 9 Bae ra 52°34 50°22 0-08
. 2 miles W. of N.W. Light
ROR conse ae tadiivlelfeaean se anees 53°04 52°50 0:10
24) -xniles\ NOW 9°44 W.. of
Walney Light ............... —— 49°70 0:08
20 smiles NW. by NA: NN:
from Point of Ayre Light
potise, EO CME: |: Cassy << saes = 49°54 0-10
SEA-FISHERIES LABORATORY. 141
7.—ESsTIMATION OF THE CarBonic Actp GAs IN SoLUTION.
100cce. of the sea water was mixed with a slight excess of
barium chloride solution and warmed till the precipitate
had settled. This was then filtered and washed, and
repeatedly treated with known amounts of standard
hydrochloric acid. As the precipitate would consist of
barium carbonate and barium sulphate, it was hoped that
the hydrochloric acid would dissolve the former. The acid
solution was then boiled to drive off the earbonie acid, and the
excess of acid estimated by titration with standard alkali,
using aurine as indicator. The alkalinity, determined by
methodsalready described, was subtracted from the value thus
obtained, when the difference was supposed to represent
the carbonic acid directly dissolved in the water.
This ought to be an accurate method, but probably it is
not, for so many processes have to be gone through that
the accumulated iron due to each probably amounts to
some considerable sum. For this reason it was only
attempted in one or two cases, and as the results seem open
to suspicion, they are not given.
8.—EstIMaTION OF LIME.
Owing to lack of time this was only done in a very few
eases. 100cc. of the sea water were mixed with ammonium
chloride solution and an excess of ammonium oxalate, and
the mixture was warmed till the precipitate settled. It was
then filtered off, washed, dissolved in dilute sulphuric acid,
and the oxalic acid estimated by titration in the heat with
standard potassium permanganate.
The permanganate solution was standardised against
weighed amounts of ferrous-ammonium sulphate. It was
then used at once.
M
142 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
The results will be found in the table at the end.
9.—MINoR CONSTITUENTS OF THE WATER.
These consist of Iron, Bromine, Ammonia, Nitrites, and
Nitrates.
None of these were estimated, though attempts were at
first made to do so, as they are present in such small
quantities that larger volumes of water than I had at my
disposal were found to be necessary for their determination.
Iron.—Attempts were made to estimate this colouri-
metrically with ammonium sulphocyanide and a standard
solution of iron alum, but it was found almost impossible
owing to the extreme paleness of the tint.
BrominE.—No attempt to estimate this was made, but
using the figures given by Dittmar in the Challenger report,
the total Halogen (not ‘Chlorme’) may be obtained by
multiplying the chlorine values given in this paper b
1°001681.
Ammonta.—This appears to be absent, or very nearly so,
as Nessler’s solution produced no visible colouration.
Nirrites.—These do appear to be present to some trifling
extent, especially at inshore stations. Their determination
was attempted colourimetrically by means of a solution of
metaphenylenediamine sulphate, but the tint obtained,
though visible, was so faint that no further trials were
made.
Nirrates.—No attempts to estimate these were made.
It is to be regretted that lack of time and apparatus
prevented me from estimating the magnesium, alkalies,
SEA-FISHERIES LABORATORY. 143
and sulphate, and also the chemical nature of the plankton,
but I hope to return to this work next summer, and take
up these matters.
10.—ConcuLusIoNn.
On considering the results which I have so far deter-
mined it seems that the waters of the Irish Sea consist of
two types :—(z) that at the Isle of Man and in the deeper
parts around, and (77) that along the Lancashire coast.
The former appears to be very little affected by tides, and
to have the salinity of ocean water, whilst the latter alters
very much both according to the tide and to the amount of
water poured out of the Mersey and other rivers. At low
tide the salinity as far out as the N.W. lightship is low,
whilst at high tide the water at the Liverpool Landing
Stage contains more salt than some other less estuarine
localities.
The alkalinity seems very irregular. It is lower round
the coasts of the Isle of Man than in some of the more open
parts, as one might expect, but its height in some places in
Liverpool Bay is remarkable. Why in the Crosby Channel
alniost at low tide it should be higher than at the Landing
Stage or the Isle of Man at high tide is not obvious; or
again, why the highest value is obtained in the Rock
Channel off New Brighton.
No sections of the water of the Irish Sea can yet be given
as too few observations have been made, but the following
table * is a summary of all the results, and will give a fair
idea of the composition of the water in the different parts.
* The .values now given supersede those in my table printed in the
L.M.B.C Annual Report. That table was incomplete and only approxi-
mate, as all the results had not then been worked out.
4 (Tt ’ [ive - .
‘ 4 <4 . ‘* a
; - wh
i bag epee. a | Sn
2: 3S ae
r
ver WE Sef trey ae a ae E
: {
" ae © - i
eed tes se ay. eke '§
~ ete wg ORI 9 annnehhniats
he Pel i o b
wy
’
: ciel
* - * ¥ ; =
18.
13,
. Landing Stage
. Landing Stage
. New Brighton
. 1 Mile N. of Barship
. Blackpool
. Piel (Barrow Channel)
. Port Erin
. Port Erin
. Fleshwick
. Douglas Bay
_ 45 Miles S.E. of Douglas........-...+1.++
. Near N.W. Light Ship
. N.W. Light Ship
- 2 Miles W. of N.W. Light Ship
LOcALITY.
ABDI ROM ICHOORCTOLO BORO WOM EON foi ICA
. Crosby Chammnel..........ssseeseeereseeseeees
wee cserserserseseeere
SOR ae BDO CONCEA OCUOU Oba Co OOTUNOLOOOG |
i
wee eee see ersssesereese
ERIC HOO. CC CnC AC OI OC OTO CCA EERE)
SIO OC OL OCH et SOOO OORT OO LIC
SOTO OIRO OOD COUN I DESO ICI ICT IG COLA) OSs
POO IDO OO OI NC OOOO SCA IC)
_ 15 Miles S.E. of Douglas......-.....-++++ |
- 30 Miles S.E. of Douglas..........-.+++++ |
eee eee eee seeeeeeee
eco censeeeseesaneeseesseasee
sane
24 Miles N.W. + W. of Walney Light
|
10 Miles N.W. by N. 3.N. from Point |
of Ayre Light House, 1.0. Mira haber
Date.
9-11-01
16-11-01
16-10-01
23-10-01
23-10-01
25-10-01
16-10-01
| 17-10-01
10-11-01
10-11-01
fa tener
9-11-01
9-11-01
9-11-01
20-11-01
28-11-01
28-11-01
25-11-01
26-11-01
|
|
|
Srare oF TIDE. -COLOUR.
High :).5 adeno Greenish grey ..
Low. jo Greenish orange.. |
High J... <coceeeeeeeee Greenish brown..
1 hour flood......... Pale olive green... }
LOW 2... cose Yellowish green ..
————— wise sooner Greenish grey ......
|". 5. ee Greenish Orey ....0m
High (after rain)... Bluish green.......
LOW is: cee Pale grey..........0mm
High ois. eee Bluish grey.....-.3m
LOW: .:.:0eeeeee Gicons grey ....am
53 hours ebb.......- Greenish blue
44 hours ebb........ Pale bluish green
33 hours ebb........ Greenish grey......
1 hour flood......... _ Pale olive green...
2 hours ebb....... al Bright yellow green
24 hours ebb.....-. Grey green .......
44 hours ebb......... | Greenish grey ...
2 hours ebb ......... Grey green ......
1:02483 i 16:78 30°32 56:12 Levey Galle ees 54:8 16°40 10°8
1:01713 11°81 91°35 48°38 ROTO) vl sels & 47:6 11.62 37:3
1:02506 17°87 32°29 58°14 SOAR | meee = 563% 17.43 4:8
1:02456 16°91 30°55 55°32 Mi Siiae [heroes 54:05 16°25 9-7
1:02658 18°33 Boe, 53-30 SVEN Nea aene 51:9 17°88 2-4
1:02513 17:30 31°26 50:90 ANG Sle, see 49°7 16°89 8:3
1°02647 18:26 32:99 50:88 OTN) I eeasor 49°6 17°81 5:0
102719 18°73 33°84 53°64 CLOW (dat Mee a3 ae Fo) 18:26 Oni
1:02719 18°75 33:87 51°76 SIO) alli ae en 50:4 18:27 0.4
1:02729 18°79 33°95 50:88 2) 55 1 I a airs 49-6 18°31 nil,
705 18°63 33°66 54:60 *1625 Ova7 yaw) 18:16 | oul
1:02736 18°86 34:07 54°86 PA GYN Oellien eens 53°4 18°38 nil.
1:02742 18:90 34°14 55:44 BOO Gala aes: 54:0 18:42 nil.
1°02723 18°76 33°89 55:28 BUGS ara ho caes. BS 18.28 0:2
1°:02571 17°69 31°96 53°30 AGE WP) anwar 52-0 IAF 49
1.02677 18°45 33°33 50°22 OLS Oo Mall dues exes 48:9 17°98 Do.
1-02678 18°45 Sono 52°50 OM [ESS 7/Ay ed | See 51-2 17°98 2:0
—-1:02681 18-47 33°37 49°70 +1492 0°58 48.4 18.01 1G
1:02709 18°67 Bono 49.54 *1469 0:57 48°3 18°20 1:0
ahs
seen
weaneeeesenenee
epncoerrnsevel
Daverasneheene sas en Se
peeeeeee
sa
3, New Brighton ..-s-ssesersesserersreeneeee
8, Port Wri .ssccsceecsecsnccsrcnseessserserses®
9. Port Erin
10, Fleshwick .....:::0sssscersecsrreceersesesees
11, Douglas Bay ......-cceeceesseseersereeenees
12. 15 Miles §.H. of Douglas.........-..-++-+. 9-11-01 | 54 hours ebb........
z
f 13, 80 Miles S.E. of Douglas...............-+. | 9-11-01 | 44 hours ebb.........
f 14, a Miles S.B. of Douglas.........:.....++- | 9-11-01 | 3} hours ebb........
15, Near N.W. Light Ship ......cceee 90-11-01 | 1 hour flood.........
PENG Wight BHI. sas ch.ssavcsenscosocasers 28-11-01 | 2 hours ebb......... |
17. oa W. of N.W. Light Ship ...... 28-11-01 | 24 hours ebb.......
18. 24 Miles N.W. } W. of Walney Light| 25-11-01
ee
19. 10 Miles N.W. by N. 4 N. from Point | 26-11-01
_of Ayre Light House, a O.M...
es ; 4, Crosby Chhammel..s.s.sevessses reser
6, 1 Mile N. of Barship ..:-s-1sesrrere 23-10-01 | Low
= eh
G, Blackpool --sssescrssecrssseerscersesenssetes
7. Piel (Barrow Channel) ....esserercerseeees 16-10-01 | ——
«CEE REE AEE ROD TONE ROONEY ; 10-11-01 | Low
10-11-01 | High
11-11-01 | Low
r suet
Yellowish green .. | _
Greenish grey
Greenish grey
| Pale olive green....
Bright yellow green
Grey green ......-...
Greenish grey ...---
Grey green ......++-
.| Bluish green........ Ce
Greenish blue ...... 102601
| Pale bluish green ..
Greenish grey......
1-01713
| 102506
1:02456
1-02513 ql A : ‘1631 |) ......
1-02647 18°26 | 32:99 | 50°88 | -1545 | ......
18°73 33°84 | 53°64 WSty WP cons:
1-02719
| 102594
| 102570
6
102575
1:02658 ‘ i Y “Gio lnees
18°86 | 34:07 54°86 G}s(0) | cases
18-90 34-14 55°44 1626 | ......
18-76 33°89 55°28 1633 aa?
17-69 31:96 | 53°30 1670 |. esses.
18-45 33°33 50°22 U5{OR) |) cece
18°45 33°33 52°50 TST || vsnswem
18-47 33°37 49-70 1492 | 0°58
18-67 33°73 49.54 1469 | 0:57
Se aes OM RAS ARNT ee
eee)
‘
4
ie pee el Re a NA | Ie ae ee tet ett le oh eae) gore on im Nap Engeat
- : 4 ;
145
foe, MEMOIRS. .
No. VIII.
PLEURONECTES.
(THE Paice.)
BY
F. J. Coin, Jesus College, Oxford,
Lecturer in the Victoria University, Demonstrator of Zoology,
Unversity College, Liverpool ;
AND
J. JOHNSTONE, B.Sc., Lond.,
Fisheries Assistant, University College, Liverpool.
(AIDED BY A GRANT FROM THE VICTORIA UNIVERSITY.)
CoNTENTS.
INTRODUCTION.
PAGE PAGE
A. EXTERNAL CHARACTERS ... 148 | EH. NERVOUS SYSTEM ............ 247
Asymmetry of Plaice 152 and 328 1. Brain and Spinal Cord... 247
ERR RVIONS 1,0. ioc seecc.cceeesccee 155 2. Cranial Nerves ............ 254
Skull and visceral arches... 155 Component Theory ...... 255
Vertebral column ............ 184 Ve=VIL Complex freciec. 265
ECCS 1 193 INN rotund us We taser. 269
Limb girdles and paired isiGomiplexs sd cescccsies 282
REE Ir komcsan sans 202 oa epimal Nerves” oo sscnesacdes 289
C. Bopy CaAviry AND VISCERA 207 4, Sympathetic .......c:s.c00. 300
1. Coelomic Spaces ......... 207° )|0.: PENSE! ORGANS’ ..jctscccecrerneaes 307
2. Alimentary canal and 1, Lateral Sense Organs ... 307
AMOS es cscnsaceccssssoers 207 ZEN OSE are amnesia a cocstsaee 315
3. Ductless glands........... a QT SIMO Be tects savaR ales sini. 318
4, Renal organs....s......05 221 Discussion of Asymmetry 152
D, BiLoop VAscuLAR SYSTEM... 228 and 328
Structure of Gills ............ 231 As TBA Ts auin aie sajne aa mene ie 334
TP ROUGODEAVICH coe sccecccc versace 940 | G. REPRODUCTIVE ORGANS...... 337
APPENDIX—ECONOMIC,
A. Lirm History Aanp Hapits.— B. PrAIceE FISHERIES .—
Distribution and Regulations and Remedial
SPAWNING ceeeerseavaee 343 MEASUTES crcvsrereecoccceneres 363
N
146 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY,
~
INTRODUCTION.
THE subject of the present Memoir belongs to the old
eroup of fishes known as the “ Teleostei,’ but the dispersal
of the “Ganoid”’ fishes has necessitated a new classifica-
tion, with the result that the familiar word “ Teleost ’ may
in the future be “ missed from its accustomed hill”’ in all
classifications of fishes. The Plaice (Pleuronectes platessa)
is the most familiar example in British seas of a group
having an almost universal geographical distribution. It
is the typical member of this group, which has long been
known as the Pleuronectide, a family of fishes belonging
to the sub-order Anacanthini.. In recent times this
family has itself received sub-ordinal rank, and has been
termed the Heterosomata, being divided into two families
(the Pleuronectide and Soleide) and six sub-families,
containing a large number of genera and species. The
principal diagnostic characters of the group are the torsion
which the anterior region of the skull undergoes during
development, and the modification and use of the left side
as the under side of the body. The lateral compression of
the body is paralleled among other Teleostean fishes, but
the [apparent] presence of both eyes on the right or left
side of the body is a unique feature.
The nearest relatives of the Pleuronectide «among the
Teleosts are the Gadide, and, curiously enough, these two
families afford the major portion of the fishes used as food
by man. The striking differences in general body form
and habits between the Plaice and Cod (typical examples
of the two groups) form a marked instance of how external
differences may coincide with deep seated morphological
similarity. The Plaice is a fish which is sluggish in its
movements, and has a very limited range of migration,
SEA-FISHERIES LABORATORY. 147
It lives, too, permanently cn the sea bottom, often buried
in the sand, feeds almost exclusively on bivalve molluscs,
and in body form departs widely from that usual in fishes.
On the other hand, the Cod is an active fish, which may
migrate over wide sea areas, and although it affects the
bottom, it may be found in any vertical zone of the sea.
Further, it is voracious and even cannibalistic, and,
although it feeds mostly on Crustacea, many marine
eroups of animals contribute to its food, whilst it has the
typical piscine form. Nevertheless, we shall show that
the morphological differences between the two fishes, apart
from the question of symmetry, are comparatively few
and unimportant. 7
The following parasites of the Plaice have come under
our own observation:—(1) Unidentified Sporozoan cysts
imbedded in the wall of the gut, and reducing it to a thin
membrane; (2) unidentified Myxosporidian cysts within
the cartilage of the auditory capsule, and causing a con-
siderable hypertrophy of the same; (3) the Cyclops stage
of Lernea, attached to the gill filaments; (4) Chondra-
canthus cornutus, inside the gill cover; (5) Lepeophthewrus
pectoralis, on the skin under the pectoral and pelvic fins ;
and (6) Bomolochus solew in the nasal chamber. ‘There are
of course others, but these we have seen.
Only seven genera and fourteen species of
Pleuronectide are known to inhabit British seas. The
members of the genus.Pleuronectes are P. platessa (plaice),
P. limanda (dab), P. flesus (flounder), P. cynoglossus
(witch), and P. microcephalus (lemon sole). All these
species are known in the Irish Sea area. The Plaice is
probably the most abundant, and the order of the species
in the above list gives the relative abundance of the others.
All are important edible fishes, and are the objects of an
active fishing industry.
148 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
A.—EXTERNAL CHARACTERS.
The Plaice is not a large fish compared with many
edible fishes, and the largest of which we find a record
was 33 inches long, 21 inches high, and weighed 1lodlbs.T
An average large plaice, however, would have an extreme
measurement of 24 inches long and 14 high. The com-
pression of the body is not from above downwards, as in
the skate, but from side to side, so that when the fish is
lying on the sea bottom its left side is downwards and the
right only is exposed. For the sake of convenience, and
for obvious reasons, we shall follow Traquair in referring to
the right and left sides as the “ ocular’
sides respectively.
’
and “ eyeless ”’
The eyeless side of the Plaice is colourless and flat,
whilst the ocular side is pigmented and convex. The
colour varies very greatly according to the nature of the
sea bottom, and may be anything from grey to dark brown.
The characteristic orange red spots (ocelli) form a row of
about 6 on the dorsal fin, 15 or so on the body, one on the
caudal fin, and another row of about 6 on the anal fin.
Specimens with the eyeless side more or less coloured, and
also reversed examples, are occasionally met with. The
nature of the colouration has been investigated by
Pouchet,f and by Cunningham and MacMunn.* We
follow the latter memoir. Ifa superficial section be made
of the fresh unprepared skin of the ocular side, two struc-
tures only are apparent. These are the colour cells or
chromatophores, situated largely in the dermis, but also
found in the epidermis, and the opaque somewhat
iridescent reflecting bodies or iridocytes. One layer of
+ Thirteenth Annual Report for 1898 of Inspectors of Sea Fisheries
(England and Wales), 1899, p. 10.
t Jour, l’anat. phys., 1877, No, 1. * Phil, Trans., 18938, B, p. 765,
SEA-FISHERIES LABORATORY. 149
chromatophores and iridocytes occurs outside the scales,
and there is another layer of both on the inner surface of
the skin and between it and the muscles. In the skin of
the eyeless side no chromatophores whatever are normally
present, and also only the external layer of iridocytes is
found. Internally, however, there is a “ thin perfectly
opaque layer of material giving a dead-white reflection.
Examined with the microscope, this layer presents only
a minutely granular structure, and is everywhere uniform
and continuous.” On account of its capacity of reflecting
light in such a way as to produce a silvery appearance it
is called the argenteum. It is doubtful whether the
chromatophores, iridocytes or argenteum are cellular
structures. It may be mentioned that Cunningham and
MacMunn were able by experiment to induce a coloura-
tion of the under side of the flounder.
The dorsal fin commences vertically above the left
eye, a short distance behind the left posterior nostril. It
extends back to the root of the tail, and is highest about
two-thirds of its length from the snout. The number of
fin rays varies considerably,t and in six specimens selected
at random ranged from 66 to 74. The anal fin commences
very far forward, immediately behind the so-called “ anal
spine,’ and stretches as far back as the dorsal fin. It is
highest at about its anterior third. In the same six
examples above the fin rays varied from 52 to 57. The
caudal fin belongs to the masked heterocercal or homocercal
type, and has usually about 20 fin rays. The pectoral fin
is situated immediately below the posterior angle of the
operculum. It has usually the same number of fin rays
on both sides (about 10), but on the eyeless side one is
small and may be overlooked. The pelvic fin is jugular
+ See especially Cunningham, Jour. M. Biol, Assoc. N. §., vol. iv., 1897.
150 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
in position, slightly in front of the pectoral, and imme-
diately in front of the anus. As far as we have seen its
fin rays never vary in number, and we have always found
six on both sides. This is very striking when we consider
the variability in the number of fin rays in all the other
fins.
The opercular fold or gill cover of the Plaice is large,
and the branchial cavity opens behind by a wide aperture.
This aperture is bounded on the inner side by the clavicle
and on the outer side by the loose branchiostegal mem-
brane supported by the branchiostegal rays. On lifting
the opercular fold the gill-like pseudobranch is easily
seen in a slight recess on the inner side of the operculum
immediately over the dorsal extremities of the gill arches.
Ventrally the opercular folds are separated by a conical
fleshy mass containing the “ inter-clavicle,’ and known as
the isthmus.
The lateral Lne of systematists commences on the
tail, and courses straight forward at about the middle of
the side of the body for the greater part of its length. It
curves slightly upwards over the pectoral fin, and there-
after becomes buried in the bones of the head. Further
portions, however, of the lateral line system are visible on
the surface, notably the right infraorbital canal under the
right eye, and a portion of the supratemporal canal under
the dorsal fin.
The scales are mostly cycloid, but according to
Cunningham (op. cit.) the so-called ‘‘ ciliated” or
“spinulated scale’’ is found only in mature males, and
may form a conspicuous local peculiarity. The scales of
this character that we have seen had three or four blunt
processes on their posterior border.
Regarding the apertures, the mouth is terminal and
markedly asymmetrical. If the mouth of a plaice be
SEA-FISHERIES LABORATORY. 151
opened, it will be seen that the whole jaw apparatus
swerves towards the eyeless side. The mechanism by
which this is effected is described elsewhere. The expla-
nation of this asymmetry is that the fish must seek its
food on the sea bottom, and the torsion of the jaws towards
the under side is hence a physiological convenience, if
not a necessity. The same consideration explains why the
teeth, which are blunt and flattened, and not pointed like
those of the cod, are situated almost entirely on the eyeless
side. Within the mouth will be seen the maxillary and
6
mandibular breathing valves, or ‘internal lips,” to pre-
vent the regurgitation of water through the mouth on the
fall of the gill cover.t The anus is situated very far
forward in front of the “anal spine,’ and is a large
median opening elongated from before backwards. The
urinary papilla of the female is distinctly on the ocular
side, a little distance above and behind the anus. The
oviducal aperture is large and lies immediately behind the
anus. It is very obvious in the spawning season, but at
other times of the year we have failed to find it, so that
it is either occluded then, or very minute. In the imma-
ture fish we believe it does not exist. In the male the
papilla is in the same position, but is here a urinogenital
papilla. We have failed to find any external distinction
between the two sexes, but the male is smaller than the
female when it first becomes mature. ‘he pair of anterior
and posterior nostrils on each side are on the ocular side
situated between and in front of the two eyes, and on the
eyeless side in front and to the left of the left eye.
Between the two eyes and passing backwards there is
a prominent ridge formed almost entirely by the right
frontal, and in a line continued back from this ridge are
t Dahlgren, Zool. Bull., 1898.
152 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
seen five tuberosities or tubercles. These may vary con-
siderably both in prominence and in number. Sometimes
only four are present, and also any one or all may be in
duplicate. As a rule, however, five occur, situated as
follows:—1 and 2 on the right frontal, 3 on the right
sphenotic, 4 on the right pterotic, and 5 on the right post-
temporal (see figs. 1 and 21).
Tur ASYMMETRY OF THE PLAICE.T
The most striking feature in the external appearance
of the plaice, and also the most interesting in its anatomy,
is the apparent presence of both eyes on the upper, right,
or ocular side. But this is not the only respect in which
the head of the Plaice has undergone torsion. The jaw
apparatus is also very asymmetrical, and in a different
direction, for whilst the eyes are twisted towards the
ocular side, the jaws incline towards the eyeless side.
Now it must be obvious at the outset that the asymmetry
of the jaws has been superimposed on that of the eyes,
and is in fact a special adaptation to an already asym-
metrical fish, living on the sea bottom, and lying on its
left side. We may therefore leave this asymmetry to be
described in its proper place, and confine ourselves to that
of the eyes.
The asymmetry of the Pleuronectide was first cor-
rectly explained by Traquair in 1865. The question is
beset with numerous difficulties, in the form of many
secondary modifications tending to mask the true course
of the original torsion. Traquair, however, in bis now
+ We have no space to refer to the extensive literature on the asymmetry
of the Pleuronectide, especially as the work of Traquair covers most of the
facts. We should like, however, to mention an interesting paper by Holt
on an abnormal sole (P.Z.S,, 1894, p. 432).
SEA-FISHERIES LABORATORY. 153
classic memoir,” the facts and conclusions of which we
can fully confirm, was enabled by an exhaustive examina-
tion of the skull and lateral line system to map out the
exact course followed by the head before it reached its
present remarkable form.
The first difficulty in the solution of the problem is
the position of the anterior extremity of the dorsal fin.
If this occupies the mid-dorsal line of the head, then it is
obvious that the left eye must have actually passed
through the substance of the head to reach the ocular side.
This ‘supposition, absurd as it may seem to us now, was 1n
fact believed by such an observer as Steenstrup. But the
anterior extremity of the dorsal fin is not situated in the
mid-dorsal line of the head. Its skeletal support (fig. 17)
and nervous supply (fig. 27.) prove conclusively, (1) that
morphologically it does not belong to the head at all, and
(2) that it has secondarily passed forwards »ver the
eranium from behind. Further, an examination of the
connection between the dorsal fin skeleton and the skull
(fig. 17) shows us that the fin extends forwards in a
straight line over the cranium without being affected in
any way by the torsion of the head. (Cp. the course of the
fin indicated in fig. 1.) It is therefore certain that the
forward extension of the fin took place after the torsion
was complete. Hence it does not occupy the median line,
but follows what Traquair calls a “ pseudomesial ” course,
and, being a purely secondary character, may be
eliminated from the discussion.
The second difficulty is the mischievous assumption
that the left eye has travelled over the top of the head to
the right side. The fact is that the left eye is not on the
right side at all. Its presence there is purely illusory.
What has happened is that the whole of the
*Trans. Linn, Soc., vol. xxv., p. 263, 1865.
154 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
cranium in the region of the orbit has rotated on its longi-
tudinal axis to the right side, until the two eyes, instead .
of occupying a horizontal plane, have assumed a vertical
one, and the left eye is dorsal to the right. Then the
dorsal fin grew forwards over the roof of the cranium, but
naturally cannot define the morphological right and left
sides of the orbital region. Thus the ocular side com-
prises not only the right side but a portion of the left,
and the true morphological median line lies between the
two eyes and not above them. ‘The relation of the eyes to
the skull is, notwithstanding the rotation of the orbital
region of the latter, exactly the same as in a symmetrical
fish, and the only differences of importance are the atrophy
of the anterior portion of the left frontal, and the purely
secondary junction under the left eye of the left prefrontal
and frontal (fig. 1).
Now whilst the above is a satisfactory answer to the
question how, it does not help us with the question why.
It is to be presumed that the first stimulus to asymmetry
was an increasing tendency of the fish to he on the sea
bottom on one side of its body. Cunningham then in-
vokes the principle of the inheritance of acquired charac-
ters, and believes that the torsion itself was produced by
the action of the eye muscles. We have considered this
point of view very carefully both per se, as a theory, and
also as a supposed explanation of the facts, with the result
that we cannot subscribe to Cunningham’s conclusions.
It is to us simply inconceivable how any action of the eye
muscles, as they are found in fishes, could have pro-
duced the existing torsion of the head, and this quite
apart from the question whether such results, if produced,
would have been inherited. ‘This, however, will be
further referred to in the section on the eye. In the
meantime we prefer to believe that the asymmetry of the
SEA-FISHERIES LABORATORY. 155
_ Pleuronectidz has been produced by the action of natural
selection, z.c., by the accumulated effects of congenital
variations.
B.—THE SKELETON.
This may be divided, as usual, into an axial and an
appendicular skeleton. We shall describe the former
first, but the precise order must to a certain extent depend
on convenience rather than upon strict logical sequence.
We therefore begin with the cranium itself, afterwards
proceeding to the remaining constituents of the skull,
then to the vertebral column and unpaired fins, and finally
to the limb girdles and paired fins.
1.—Craniumt (Figs. 1 to 4).
Owing to the difficulty of making an independent
preparation of the chondrocranium it is, in the following
description, described in the pieces into which it is divided
when the cranium is disarticulated. f
Seen from behind (Pl. IL, fig. 4) the ceciput is
markedly asymmetrical, and a line traversing median
structures would be convex towards the ocular side. This
is observable also in the occipital condyle and in the
paroccipital condyles (O0.C., P.C.), and of the latter, the
eyeless one, as may be assumed from the description of the
atlas, is larger than the ocular. In those two extensions
of the auditory capsule, the epiotic and parotic processes
+ Cp. especially, Traquair, Trans. Linn. Soc., xxv., p. 263. Space
forbids a discussion of the literature in the text, but the following papers
should be consulted :—Schmid-Monnard, Jena. Zeits., xxxix.; 7. J. Parker,
Trans. Zool. Soc., xii., p. 5; Sagemehl, Morph. Jahrb., ix., p.177; x., p.1;
Xvil., p. 489; Shufeldt, Report U. 8. F. C., 1883, p. 747; Alls, Jour.
Morpa., x., p, 487; xiv., p. 425; Zool. Bull.,i., p. 1; Anat. Anz.,xvi.,
p. 49; xvii., p. 433; Cole, Trans. Linn. Soc., ser. ii. vii., p. 115; W. K.
Parker, Phil. Trans., vol. 173, pp. 189 and 443: vol. 163, p.95; MeMurrich,
Proc, Canadian Inst., N. S., ii., p. 270; Brooks, Sci. Proc. R. Soc., Dublin,
Bvim:, 1V., ps 166,
156 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
(fig. 4, Hp.P., Pa.P.), there is a marked difference from
the cod, the former being more prominent than the latter,
instead of vice versa. |
In a dorsal view (fig. 1) the asymmetry is most pro-
nounced in front of the parietal region. In the cod the
frontals completely meet (and indeed fuse) in the mid-
dorsal line. In the Plaice, on the other hand, there is a
very wide separation of the frontals anteriorly, so as to
form a large secondary frontal fontanelle or left orbit.
The asymmetry is, however, more evident on the
ventral surface (fig. 2). This is due to the fact that in
front of the alisphenoids there is no side wall to the
cranium, which, therefore, here consists cf the paras-
phenoid only. In front of the prootic the parasphenoid
turns sharply towards the eyeless side to such an extent
that the head of the vomer was, in the specimen figured,
deflected by about a centimetre from the middle line. As
the parasphenoid is the most prominent feature on the
base of the cranium, the appearance of torsion in this
region is, in a full-sized fish, most striking.
Seen from the side the cranium on the eyeless side
falls more into one plane than on the ocular, but this is
obviously due to the inclination of the parasphenoid and
vomer to that side (cp. fig. 2).
The interior of the brain case is extremely irregular.
Owing to the lateral walls meeting ventrally at a some-
what acute angle a false floor for the brain becomes neces-
sary, and this consists of two distinct parts. In front
there is a rather narrow transverse bridge connecting the
two alisphenoids, a strong sutural union being effected in
the middle line. Behind there is a similar but much
broader bridge joining the two prootics, the two processes
meeting as before in a median suture. The true floor of
the cranium is formed in the former of these cases by the
Bit a 6 a le
SEA-FISHERIES LABORATORY. 157
a
parasphenoid and in the latter partly by the prootic and
partly by the parasphenoid. In both cases there is an
obvious space between the false and true floors, and this
space is the eye muscle canal. At the region of this
posterior bridge the side walls of the cranium are greatly
strengthened internally (and the cranial cavity hence
reduced) by a stout ridge of bone borne on the prootic,
sphenotic and supraoccipital. From the middle of this
ridge there extends backwards another process which be-
comes larger and more complex as it passes backwards.
This is formed mostly by tke sphenotic, supraoccipital,
pterotic, epiotic and exoccipital, and consists of both bone
and cartilage. It is here that the cranial wall is thickest.
The foramen magnum does not open at once into the
eranial cavity, but into a bony canal formed by the
basioccipital and exoccipitals (fig. 4).
Basioccipital (B.0., figs. 2, 3, 4).—A stout bone,
partly cartilaginous in front, and bearing the single con-
cave occipital condyle for the centrum of the atlas. Above
it forms a small portion of the floor of the foramen
magnum. Mid-ventrally it exhibits a deep depression
into which fits the posterior extremity of the parasphenoid.
The basioccipital is bounded above by the exoccipitals,
and laterally by the prootics, opisthotics and exoccipitals.
Exoccipital (Hw.0., figs. 2, 3, 4)—Forms most of the
occipital foramen or foramen magnum (fig. 4, #’.d7.). It
is not completely ossified, and above its cartilage forms
part of the cross-shaped wedge of cartilage appearing on
the surface of the occiput (fig. 4). Each exoccipital bears
a very prominent ridge and concave facet lined with car-
tilage for the corresponding process on the atlas. The
asymmetry of these paroccipital condyles (P.C.) has been
elsewhere noticed. The exoccipital is bounded above by
the epiotic, laterally by the pterotic and opisthotic, below
158 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
by the basi-occipital and opisthotic, and internally by its
fellow of the opposite side. It bears a conspicuous
foramen with a long canal (/.vg., figs. 2, 3) for the exit of
the vagus nerve, and at least one other for the first spinal
nerve.
Supraoccipital (S.O., figs. 1, 4).—A large asymmetri-
cal bone hardly appearing on the occiput, from which it is
excluded by the epiotics, and having only a feeble
occipital spine (Oc.S.), so well marked in the Cod. This
spine and ridge is continued forwards to the left anterior
corner of the bone, where it forms a furrow developed in
connection with the interspinous bones or axonosts of that.
part of the dorsal fin situated over the head, as elsewhere
described. In front the supraoccipital is thin and
laminate, so that the roof of the cranial cavity is here very
slender, but behind the cerebral surface cf the bone is
supported by three strong ridges of bone and cartilage.
The supraoccipital is bounded in front by the frontals,
laterally by the parietals, and behind by the epiotics.
The basi-, ex- and supraoccipitals together form the
occipital segment of the cranium.
The Auditory Capsule of the Plaice is formed by the
following five bones, as in the Cod: —
Sphenotic (Sp.O., figs. 1, 2, 3).—Does not contain
much cartilage. Externally on the dorsal surface a strong
process is sent out and supported by a ridge of bone
coming up from below. The sphenotic forms the external
and upper half of the deep cup for the ball of the
hyomandibular (cp. fig. 5), the prootic half of the same
being more or less separated from it by a strip of the
chondrocranium (cp. the two sides in fig. 25 Hm.f.*).
The cerebral surface of the sphenotic has two large cavities
separated by a thick wall of bone and cartilage. The
sphenotics are not quite symmetrical—that of the ocular
SEA-FISHERIES LABORATORY. 159
side being the larger and more densely calcified. They are
bounded by the frontal, alisphenoid, prootic, pterotic and
parietal.
Prootic or Petrosal (Pr.O., figs. 2, 3)—A stout bone
containing a quantity of cartilage. It is perforated by the
large canal or foramen jugulare (f.jug.), which transmits
the internal jugular vein, the ophthalmic artery and the
truncus hyomandibularis nervi facialis. It also forms
the postero-lateral wall of the trigemino-facial foramen
(f.tr.fa) and the external wall of the carotid foramen
(f.car.), transmitting the internal carotid artery. Further
it forms the internal and lower half of the hyomandibular
cup (Hm./’.*), and its part in forming a false floor to the
cranial cavity by processes of bone and cartilage has been
already mentioned. ‘The prootic has two conical depres-
sions on its cerebral surface, the ventral one being much
the larger. It is bounded by the parasphenoid,
alisphenoid, sphenotic, pterotic and basioccipital.
Epiotic (“p.0., figs. 1, 3, 4)—A dense structure
largely cartilaginous, but having a thin outer shell of
bone, prolonged into the somewhat prominent epiotic
process (p.P., fig. 4). The cerebral surface bears two or
three deep conical pits with a thin bony lining, cne being
much larger than the others. The epiotic provides the
remainder of the cartilage for the occipital cross already
mentioned. It is bounded by the supraoccipital, parietal,
pterotic and exoccipital. |
Pterotic (/t.0., figs. 1, 2, 3)—Forms the greater part
of the parotic process (Pa.P., fig. 4). It is more densely
calcified than the epiotic, and its cerebral surface bears
three deep conical pits, one being partially subdivided
into two. Laterally it bears an imperfect oval bony facet
for the posterior condyle of the hyomandibular (Hm.F.?,
figs. 2, 3, and ep. fig. 5). The left facet is appreciably
160 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
larger than the right (cp. description of the hyomandibu-
lar), in contradistinetion to the hyomandibular cup which
is smaller on this side. The pterotic forms the anterior
boundary of the glosso-pharyngeal foramen as shown in
fig. 2 (f.gl.). It is bounded by the parietal, sphenotiec,
prootic, opisthotic and exoccipital.
Opisthotic or Intercalar (Op.0., figs. 2, 3, 4)—_Forms
the remainder of the parotic process. It is by far the
smallest of the otic bones, consists of a thin flat plate of
irregular shape, and contains no cartilage whatever. Its
development should therefore be studied. It forms the
posterior boundary of the glosso-pharyngeal foramen (f.g/.,
figs. 2, 3), and is bounded by the basioccipital, pterotic
and exoccipital.
There can be no question in forms such as the Cod
and Plaice that the ear bones described as pterotic and
sphenotic are something more than what they seem, 2.¢.,
they have a compound and not a simple origin. Added to
the so-called cartilage bone in each case is a dermal
element, originally developed around that part of the
sensory canal system associated with these bones, and now —
more or less completely fused on to them. In some Fishes
(such as the sphenotic of Amza) the two portions remain
distinct throughout life, and in others the iine of fusion
may be plainly seen, with, however, the bones remaining
separate as an occasional abnormality (such as the pterotic
of the Cod). But as a rule the two portions fuse com-
pletely, so as to be indistinguishable in the adult. Now
in the one case the terms pterotic and squamosal have
been applied indifferently to the compound of the adult.
We may therefore, in those cases where the two parts of
the compound remain separate in the adult, call the car-
tilage pterotic, or ear bone, the true pterotic, and the
dermal pterotic, or lateral line bone, the squamosal. In
SEA-FISHERIES LABORATORY 161
the other case, however, in which the terms sphenotic and
post-frontal are synonyms, we cannot adopt the same plan,
since the term post-frontal cannot be correctly applied to
a membrane bone in Fishes. We must hence distinguish
between the cartilage true sphenotic, or ear bone, and the
dermal sphenotic, or lateral line bone, without giving the
latter a definite name. The subject would repay investi-
gation.
Parietal (Par., figs. 1, 3).—Flat conspicuous bones
containing of course no cartilage. On the dorsal surface
the inner portion is laminate, but the outer portion is
much more densely calcified (cp. fig. 1). The boundary
separating these two parts 1s where the skull begins to
shelve down. The two parietals are markedly asymmetri-
eal, as shown in fig. 1. The parietal is bounded by the
supraoccipital, frontal, sphenotic, pterotic and epiotic. _
Alisphenoid (A/.S., figs. 2, 3)—Forms, as described
above, a false floor to the cranial cavity, separating the
latter from the eye muscle canal. The greater part of the
dorsal portion of the alisphenoid consists of two thin
plates of bone with a layer of cartilage between them.
Behind, the alisphenoid forms the anterior boundary of
the foramen for the fifth and seventh cranial nerves, and
it is at this region that the bone is most densely calcified.
li is bounded by the parasphenoid, prootic, sphenotic, and
frontal. In front a portion of the border is free.
Anterior to the parietal region the asymmetry of the
skull is most emphasized, and its rotation in the direction
of the hands of a watch is quite manifest. ‘The bones of
the two sides therefore differ more or less considerably.
Right Frontal (/0./’r., figs. 1, 2, 3).—Very elongated
from before backwards and narrowed from side to side.
It is the anterior prolongation of the right frontal that
forms the stout bar between the eyes so prominent in the
0)
162 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
undissected fish. The right frontal, lke the left, is
bounded by the frontal of the other side, supraoccipital,
parietal, sphenotic, alisphenoid, the prefrontal of its side
and median ethmoid, except that the left frontal does not
reaeh the median ethmoid.
Left Frontal (Z.F'r., figs. 1, 2, 3)—Takes no part in
forming the interorbital ridge. Compared with the right
frontal it is broad from side to side and shorter from
before backwards. As shown in figs. 1 and 2, it sends out
on the right a strong transverse process which overlaps —
the dorsal surface of the right frontal. The forward
process on the left of the left frontal lying over the left
prefrontal, together with the posterior portion of the latter
bone, are lying apparently in a very anomalous position,
2.e., they are situated under the left eye instead of over it.
This, however, has been produced by the frontal growing
forwards, and the prefrontal growing backwards, after the
torsion of the cranium was an accomplished fact. It is
thus a precisely analogous case to the anomalous position
of the anterior extremity of the dorsal fin.
Prefrontal (/?. and L. P.F'r., figs. 1, 2, 3)—The left
prefrontal is in every respect larger than the right—due
apparently to the circumstance just mentioned. Both
contain in front some cartilage which is continuous with
what we have termed the ethmoid cartilage. Both also
are perforated by a foramen transmitting the olfactory
nerve to the olfactory lamine of the nasal organ, the left
foramen being perceptibly smaller than the right—due
to the lett olfactory nerve being so much smaller than the
right. The left prefrontal fits by means of a long narrow
backward process into a groove on the dorsal surface of the
front end of the parasphenoid—a process entirely absent
on the right side. The articular surface for the lachrymal
is smaller on the left side, and similarly the process
SEA-FISHERIES LAPBORATORY. 1638
bearing it is also the smaller of the two (ep. fig. 1). Above
the olfactory foramen the left prefrontal is prolonged
upwards and backwards to assist the median ethmoid in
forming the anterior boundary of the left orbit. This
process is practically absent on the right side. The pre-
frontal, which is called by other authors ectethmoid,
lateral ethmoid, parethmoid, or paired ethmoid, is bounded
by the lachrymal, vomer, mesethmoid, ethmoid cartilage,
and frontal, the left one further by the parasphenoid.
Mesethmoid (1/./., M.E.', figs. 1, 5)—Presumably
an ossification of the ethmoid cartilage. In front it bears
a prominent beak (J/.H.1), and above this is a depression,
both of which are connected with the motion of the inter-
maxillary cartilage. The marked inclination of the
former to the eyeless side will be noted, thus diverting the
motion of the jaws to that side. Behind, the mesethmoid
is laminate, and takes a sharp turn upwards, forming by
a graceful curve the anterior wall of the left orbit, the
remainder of which is contributed by the left prefrontal.
In front and on each side of the mesethmoid the ethmoid
cartilage appears on the surface of the cranium, whilst
behind and above on the right is an attachment for the
right nasal. The mesethmoid is bounded by the vomer,
ethmoid cartilage, prefrontals, right nasal and right
frontal.
Ethmoid Cartilage (Mth., figs. 1, 2, 3)—An asym-
metrical unpaired cartilage quite separable in the
macerated skull except for those portions embedded in the
prefrontals. It consists of two parts, one a long basal
horizontal rod tapering to a point behind and fitting into
a deep groove on the upper surface of the parasphenoid
alongside the caudal process of the left prefrontal, the
other a vertical plate with a marked deflection to the
ocular side and perforated by a large fenestra. The latter
164 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
transmits the origins of the two right oblique muscles of
the eye. The ethmoid cartilage appears on the surface of
the skull on each side of the mesethmoid immediately
above the vomer. It is bounded by the parasphenoid, the
prefrontals, mesethmoid and vomer.
Vomer (Vo., figs. 1, 2, 3).—A median unpaired bone
consisting of an anterior head and a posterior shaft taper-
ing to a point. The latter is firmly fixed into a long
tapering cavity in the base of the parasphenoid to such an
extent that the extremity of the parasphenoid is brought
very near the anterior end of the vomer. The cavity in
the parasphenoid lodging the vomer is quite distinct from
that immediately above it for the ethmoid cartilage and
the left prefrontal. The head of the vomer is inarkedly
asymmetrical, and has a laminate process on each side, the
right of which is appreciably larger than the teft. In
front the vertical face is inclined towards the eyeless side,
thus further deflecting the motion of the intermaxillary
cartilage, and hence the jaw apparatus, to that side. The
vomer is bounded by the parasphenoid, prefrontals,
etnmoid cartilage and mesethmoid.
Parasphenoid (Pa.8S., figs. 1, 2, 3)—A very long un-—
paired bone with a prominent keel. It is very asymmetri-
cal, taking at the region of the alisphenoids a sharp turn
towards the eyeless side. Behind it fits into a depression
on the base of the basioccipital, and forms a portion of the
floor of the cranial cavity in front of the latter bone, its
dorsal surface being here deeply grooved. Its relations
in front to the ethmoid cartilage, left prefrontal and
vomer have been described above. The parasphenoid is
bounded by the basioccipital, prootics, ahispheias left
prefrontal, ethmoid cartilage and vomer.
Nasal (/?.Va., figs. 1, 2, 3).—Only the right nasal is
present—the left having completely aborted with the
SEA-FISHERIES LABORATORY. 165
almost complete loss of the left supraorbital sensory canal,
the anterior extremity of which it is its main function to
protect.t The existence of the left nasal would cf course
also be jeopardised by the motion of the intermaxiliary
cartilage over the beak of the mesethmoid, which, whiist
not affecting the right nasal, would tend to reduce the left.
It is necessary to assume some co-operative cause such as
this, since the disappearance of a sensory canal does not
necessarily involve the reduction of the true lateral line
bones, or the Plaice would not possess a right lachrymal.
The nasal of the Plaice is a small semilunar bone attached
to the right side of the posterior vertical plate of the
mesethmoid. It supports the anterior extremity of the
right and only supraorbital sensory canal, and bounds the
right nasal sack internally. It is sometimes called the
turbinal.
Lachrymal (/?.Lc., L.Lc., figs. 1, 2, 3)—These have
been modified from the first of the suborbital series or
chain of lateral line ossicles supporting the infraorbital
sensory canal, and may hence be called the first sub-
orbitals. ‘They have also been called the adnasal bones,
on account of their relations to the nasal sack. In the
Plaice they differ from the bones of the same name in
most Teleosts (including the Cod) in being closely
attached to the cranium. They differ in shape as shown
in fig. 1, the left being more concentrated than the right
(the latter best shown in fig. 3). The right lachrymal has
no connection whatever with the right infraorbital sensory
canal. Both lachrymals bound their nasal sack externally,
+ Traquair (loc. cit., p. 284) describes a “minute turbinal [nasal]
ossicle”” on the left side, supporting the ‘‘remnant of the main (supra-
orbital] canal of the eyeless side.’ We have found the latter in our sections
as Traquair describes it (see elsewhere), but not the rudimentary nasal.
Dr. Traquair’s work, however, is so accurate, that he is doubtless correct in
this also.
166 ‘TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
and are both attached to anterior projections from the
prefrontals in the manner described above.
The suborbital and supratemporal chains of lateral.
line ossicles are described with their respective sensory
canals.
2.—TuHEe Parato-PreryGorp ARCADE (Fig. 5).
Ocular Side.
Hyomandibular (/7m.).—This bone articulates with
the skull in two ways. First by a well marked ball and
socket joint situated at the anterior extremity of its
articular surface, and second by a !ong and less con-
spicuous facet behind this. The socket is a deep depres-
sion very obvious in dried skulls and situated between the
sphenotic and prootic. From this depression the other
facet passes upwards and backwards, and is placed mostly
if not entirely on the pterotic. The head of the hyoman-
dibular is cartilaginous in three places, at the two facets
for the skull and at the projection articulating with the
operculum. Parallel with the posterior edge, and at a
short distance from it, is a stout bony ridge (the most
strongly calcified part of the bone) which is closely
attached to the pre-operculum. In front of this a shaft
of cartilage passes downwards and forwards, which bears
a thin cartilaginous cap, and articulates with the inter-
hyal in such a way as to admirably illustrate what is now
a commonplace of vertebrate morphology, that the
hyomandibular is the modified dorsal segment of the hyoid
arch, which has in many forms lost its connection with
the hyoid arch, and has acquired on the one hand a con-
nection with the auditory capsule and on the other with
the jaw suspensorial apparatus. The Plaice is therefore
hyostylic. The remainder of the ventral edge of the
SEA-FISHERIES LABORATORY. 167
hyomandibular articulates with the meta-pterygoid. In
front of the cartilaginous shaft it simply consists of a thin
leafy plate—a part which is absent in the Sole according
to Cunningham.
Symplectic (Sy.).—Consists of a cartilaginous shaft
with a semilunar plate of bone opposed to its anterior
edge. Its head forms with the shaft of the hyomandibu-
lar the cup for the upper end of the inter-hyal, and also
bears a cartilaginous epiphysis. Ventraliy its extremity
hes under the quadrate. Its anterior bony margin is
attached to the metapterygoid and its upper posterior edge
to the pre-operculum.
Quadrate (Qu.).—A laminate bone bearing posteriorly
a strongly calcified ridge and ledge for the pre-operculum.
Dorsally it is prolonged into a spine situated in front of
the pre-operculum and wedged in between that bone and
the symplectic. In front it articulates with the pterygoid,
and below its free extremity bears a stout knob with a
saddle-shaped articulation for the articular.
Meta-pterygoid (1/.Pi.)—A very thin leafy bone
attached to the hyomandibular above, the symplectic
behind, the quadrate below, and the meso-pterygoid in
front below.
Meso- or Ento-pterygoid (J/s.Pi.).—Also a thin leafy
bone very strongly attached to the pterygoid below. Its
lower border in front is more strongly calcified than the
rest.
Pterygoid or Ecto-pterygoid (/%.)—A peculiarly
shaped bone. It consists of a strongly calcified piece
having the shape of an isosceles triangle, the apex point-
ing downwards and forwards. When the jaws are shut it
is opposed in front to the articular of the mandible. From
the posterior angle of its base it sends forwards almost at
right-angles a transparent bony rod which is tightly
168 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
wedged in, and connected by ligament with the meso-
pterygoid and the palatine, as in Sebastolobus.t
Palatine (Pa.).—A curved rod largely of bone, but
partly of cartilage. Its posterior half is partly cartila-
ginous and is closely connected with the meso-pterygoid,
pterygoid, and the anterior angle on the base of the ptery-
goid. Its anterior half is bony except at the extremity,
which bears a cartilaginous cap attached by ligament to a
dorso-posterior elevation on the maxilla. The palatine
sends down opposite the anterior end of the meso-ptery-
goid a rounded process which is strongly attached to the
enlarged anterior extremity of the vomer, and apparently
also to the ventral process of the pre-frontal as described
by Brooks{ in the Haddock. In the natural disposition of
the bones the palatine lies internal to the maxilla.
Eyeless Side.
Hyomandibular.—Much smaller and less densely
calcified, and is altogether an obviously feebler bone,
although the ball and socket articulation with the skull,
whilst slightly smaller, is yet deeper and stronger. The
cartilaginous cap for the inter-hyal is also present on this
side.
Symplectic.—Considerably shorter, but more robust,
and has only a cartilaginous wedge at its upper extremity.
Quadrate.—Slightly shorter but wider antero-
posteriorly and more densely calcified, especially at its
free ventral extremity. Its dorso-anterior margin is,
however, cartilaginous where it articulates with the meta-
pterygoid.
Meta-pterygoid.—Somewhat shorter and narrower,
} Starks, Proc. Californian Acad. Sci., ser. iii., vol. i., 1898.
t Sci. Proc. R. Soc., Dublin, iv., 1884.
SEA-FISHERIES LABORATORY: 169
but the same thin laminate bone. Has only a slight
articulation with the meso-pterygoid in front instead of
the extensive one of the other side.
Meso-pterygoid.—Not attached to the dorsal edge of
the pterygoid but to its inner face. It hence occupies a
different plane to that of the meta- ee It is further
much smaller on this side.
Pterygoid. —This is of a different shape on this side.
The forward thin rod is here thick and in fact stouter
than the remainder of the bone, which is reduced and
apparently merged into the forward portion. The left
pterygoid is both larger and stouter than the right—thus
differing from the left palatine, as will be seen below.
Palatine.—Greatly modified on this side. Its anterior
extremity articulates directly with the upper end of the
maxilla instead of by the intervention of a short igament.
In one specimen there was also a short hgament contain-
ing a sesamoid connecting the same extremity with the
anterior forward process of the pre-frontal. Behind the
anterior end there is a strong dorsal articulation with the
pre-frontal which is not found on the other side. The
ligamentous connection with the vomer also exists on this
side, but is apparently with the vomer only. The articu-
lation with the pterygoid is also different, the posterior
extremity of the palatine being forked and the pterygoid
fitting into the split thus formed, the interstices being
filled with cartilage. The left palatine is much shorter
than the right, but is more robust (cp. the pterygoid).
3d.—THE JAw Apparatus (Fig. 5).
Ocular Side.
Articular (Ar.).—Has a saddle-shaped articular sur-
face for the quadrate, behind which it sends up a promi-
170 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
nent “ post-glenoid”’ process. The bone is stoutest at
this region, but becomes gradually lamelliform forwards,
and its anterior margin is furcate—the lower limb fitting
into the cavity of the dentary. The quadrate facet is
cartilaginous. The outer face of the articular is convex,
the inner concave.
Angular (An.).—A small but perfectly distinet bone
situated at the postero-inferior angle of the articular.
Meckel’s Cartilage. —A long thin rod cf cartilage
embedded in the articular behind, but lying quite freely
for the greater part of its length. It is situated near and
parallel to the ventral border of the inner or concave face
of the articular and projects slightly beyond the anterior
extremity of the ventral limb of the latter, the free end not
being ossified as a mentomeckelian as in Amza. The free
portion of Meckel’s cartilage was 12mm. long in the speci-
men now described, and in a very large fish it attains a ©
diameter of about 2mm.
Dentary (D.).—A thin bone, but well ossified at its
dorsal and ventral borders and strongly attached to the
dentary of the other side. It is strongly and almost
equally forked behind, and contains a iarge triangular
cavity for the reception of the lower limb ef the articular.
Like the latter, its outer face is convex and the inner
concave. Quite near the symphysis it on this side and in
this specimen bore 3 teeth, opposite to which on the ven-
tral border a prominent process was set down. In a very
large specimen examined there were no teeth cn this side,
their position being occupied by a roughened ridge.
Maxilla (d/2.).—Takes no part in the gape. A stout
club-shaped bone, the expanded lower extremity of the
handle or shaft of which overlaps the lower jaw externally
at about the junction of the articular and dentary when
the mouth is closed. The shaft narrows down before ex-
SEA-FISHERIES LABORATORY. 171
panding to form the head, which is capped with cartilage.
The head has 4 articulations: (1) It is closely attached
above to the large unpaired intermaxillary cartilaget
(7.M.C.), to which on its other side the left maxilla is also
attached ; (2) ventrally the maxilla is capped by a move-
able piece of cartilage, much smaller and situated ventral
to the inter-maxillary. This moveable or gliding car-
tilaget works in the groove to the right of the beak-like
mesethmoid prominence (cp. fig. 1), and also over the
large convex facet on the right side of the head of the
vomer. It is connected with the inter-maxillary and is
excavated on both surfaces to receive the head of the
maxilla and the vomerine facet. The latter or free exca-
vation is so contrived as not to interfere with the move-
ment of the cartilage above the vomer. The reader who
consults a dried cranium of the Plaice when reading this
description will understand that the movement permitted
to the maxillary bones by these facets and gliding car-
tilage is an oblique dorse-ventral one in the direction of
the eyeless side (cp. Traquair op. ct.). This explains the
well-known fact that Plaice are able to pick up food lying
on the sea bottom by twisting the mouth towards the lower
or eyeless side. In other Pleuronectide the twisting of
the mouth is towards the ocular side; (3) dorso-posteriorly
the maxilla, as already pointed out, is connected by liga-
ment with the anterior extremity of the palatine; (4)
anteriorly and externally it is deeply excavated for the
reception of the pre-maxilla. The anterior edge of the
maxilla is close to and partly overlaps the pre-maxilla.
Pre-Maxilla (P?.4/v.).—Forms the dorsal part of the
gape and consists of two arms. Its vertical arm forms the
gape and bore 4 teeth in the specimen now described,
{ We follow Traquair in using this term for the cartilage in question.
+ Cp. Traquair, Trans. Linnean Soc., London, xxv., 1865.
172 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
which, however, contrary to those of the opposite side,
were placed nearer the posterior edge of the pre-maxilla
than the anterior. Dorsally this arm is closely connected
with the left pre-maxilla. ‘The posterior arm passes back-
wards over the inter-maxillary, with which it is closely
connected. At the junction of the two arms a process is
sent backwards which is both capped with cartilage and is
covered by a further loose moveable piece. This process
fits into the excavation on the maxilla already described,
and hence the pre-maxilla here overlaps the maxilla.
Inter-Maxillary Cartilage (/.4/.C.)—This cartilage
plays an important part in the movement of the jaws. It
is asymmetrical, blunt in front but more pointed behind,
and forms as it were a pivot on which the two maxillary
bones on each side turn. It fits into the depression very
obvious in the dried cranium above and to the !eft of the
mesethmoid prominence, and glides up and down from
this depression over the prominence itself. Its posterior
surface is obliquely grooved, and in such a way that as it
moves downwards it passes obliquely over the prominence
towards the eyeless side—thus further assisting in the
torsion of the jaws to that side.
Eyeless Side.
Articular, Angular and Meckel’s Cartilage—The two
former are slightly larger than the right, and are also
slightly more densely calcified, but the differences are
small. Meckel’s cartilage was in the specimen now
described 2mm. longer on this side.
Dentary.—<Appreciably larger and more densely calci-
fied, and is strongly curved whilst the right is almost flat.
The forking of the posterior margin is further very
unequal, the lower limb being much the larger (ep. fig. 5).
The depression at about the middle of the outer face of the
SEA-FISHERIES LABORATORY. 173
articular immediately in front of the quadrate articulation
for the M. adductor mandibule is much more marked on
this side, where the muscle is naturally larger and,
further, the distortion of the jaws to the eyeless side 1s
assisted by a tendon from it inserted into the maxilla.
The dentary of this side bore 22 teeth, as against 3 on the
right side.
Maxilla.—Distinctly larger and more curved than the
right but not so robust. At about a third from the head
on the posterior edge is an eminence for the attachment of
a stout tendon arising in connection with the M. adductor
mandibule, and the action of which tends to draw the
jaws towards the eyeless side. This eminence and tendon
are not conspicuous on the ocular side, and indeed in the
Sole, where the ocular is also the right side, the tendon is
stated by Cunningham? to. be absent on the eyeless side,
although the muscle is said to be larger on that side. The
eminence is figured, and the muscle described by Tra-
‘quair,t who calls the latter the Retractor Maxille.* At
the head of the maxilla on the posterior side the bone
articulates directly with the free anterior extremity of the
palatine instead of by the interposition of a short liga-
ment. The cap of cartilage gliding over and above the
head of the vomer is larger and the terminal free facet is
also more extensive. The whole action of-the jaw appa-
ratus is markedly asymmetrical owing to the unpaired
mesethmoid prominence separating the two maxillary
facets being obliquely set towards the right. Hence when
the maxille are depressed they follow an oblique direction
towards the left or eyeless side. The articulation of the
maxilla with the pre-maxilla is also modified on this side.
On account of the motion of the jaws towards the left the
+ The Common Sole. Plymouth, 1890, p. 48. + Op.cit., p. 279, Tab. 30.
* Cp. also. Allis, Jour. Morph., xii., pp, 552 and 576,
174 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
head of the maxilla is brought into closer connection with
the posterior ascending process of the pre-maxilla. Then
again the posterior articular process for the maxilla at the
junction of the two arms of the pre-maxilla is smaller, and
instead of overlapping the maxilla is overlapped by it.
Pre-Maxilla.—Both arms are longer and stouter. The
ascending arm is at right-angles to the oral arm instead
of at an obtuse angle as on the right side, and passes over
the inter-maxillary more to the middle line of that ecar-
tilage. It bore in this specimen 17 teeth as against 4 of
the other side, and set, as already stated, in a different
plane.
The asymmetry of the suspensory and jaw apparatus,
whilst undoubtedly initiated by the torsion cf the
cranium, has also been independently emphasized by the
habits of the fish, as already described. The broad
anatomy of this distortion is as follows: (1) The suspen-
sory apparatus on the right side is mostly longer—thus
thrusting the jaws over to the left; + (2) the motion of the:
maxille at the sides of the mesethmoid prominence and
over the head of the vomer and the course of the inter-
maxillary over the mesethmoid beak itself is an oblique
one with a set towards the left, which the pre-maxille and
mouth must necessarily follow. The jaws themselves and
the bones immediately related to them are naturally more
robust on the left side, since their function is mostly per-
formed on that side. Hence the practical absence of teeth
on the right pre-maxilla and dentary.
4.—Tnr OrEercuLar Bones (Fig. 5).
Ocular Side.
Operculum (Ovp.).—A thin laminate bone containing |
no cartilage: except at the articular cup. It is bifid pos-
+ Cp. Traquair, op. cit., Tab. 30 and pp. 276-7.
SEA-FISHERIES LABORATORY. 175
teriorly, the apex of the lower arm overlapping the sub-
operculum. Its anterior extremity is greatly strength-
ened by a median ridge of bone deeply cupped in front
and forming a strong ball and socket joint with a process
on the posterior margin of the hyomandibular.
Sub-operculum (S.Oy.).—Described in the Sole by J.
T. Cunningham as the “ Inter-opercular.” A leafy bone
thinner than the operculum, sending upwards and back-
wards a long process behind the bifid margin of the
operculum. Ventrally it overlaps a small portion of the
inter-operculum. The operculum and_ sub-operculum
support the posterior free margin of the opercular fold,
and the characteristic posterior process at the base of the
pectoral fin (see fig. 23) is formed by the upper extremity
of the sub-operculum and the upper limb of the oper-
culum. :
- Inter-operculum (/.Op.).—The “ Sub-opercular” of
Cunningham. A thin bone but stouter than the sub-
operculum. It stiffens the ventral free margin of the
opercular fold. The whole of its dorsal edge lies under
the pre-operculum, and at about the middle of this edge
there is a depression (and here, as in the operculum, the
bone is thickest and most strong), providing a ligamentous
articulation with the inter- and epi-hyals at the junction
of the two latter—a somewhat similar condition to that
found in Amia.t The connection of the operculum and
inter-operculum (and especially the latter) with the hyoid
arch, both apparently common in the bony fishes, confirms
_ the view that these elements are modified branchiostegal
rays. ‘The sub-operculum is probably also another.
Pre-operculum (P.O p.).—This is usually considered
to be a modified lateral line bone, 7.e., a bone developed
primarily around a portion of the lateral line system, and
f Allis, Jour. Morph., xii. Cp. also Shufeldt, Report U.S. F. C., 1883,
176 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
is therefore probably not homologous with the other oper-
cular bones. In the Plaice it is L shaped and above over-
laps a portion of the hyomandibular. Its straight anterior
margins are closely connected with the hyomandibular,
symplectic, and quadrate. Opposite the ventral edge of
the hyomandibular it almost completely covers the inter-
hyal. Ventrally it overlaps the posterior edge of the
quadrate. It is the stoutest of the opercular bones—its
anterior surface especially being strongly calcified.
Eyeless Side.
The relations of the bones are precisely the same, but
the following differences in shape, &c., may be noted :—
The operculum is slightly smaller and not quite so
strongly calcified, and the sub-operculum, though smaller,
is somewhat stiffer than the right. The pre- and inter-
opercula are both distinctly smaller and less calcified, and
hence the asymmetry is most marked in the anterior
opercular bones.
The bonest which enter more or less into the forma-
tion of the entire skull of the Plaice may now be pro-
visionally arranged in the following categories according
to their manner of origin : —
A.—Bones formed as ossifications within the primi-
tive cartilaginous brain case of the embryo : —Alisphenoid
(AL.S.), Basioccipital (B.O.), Epiotic (F'p.0.), Exoceipital
(Hx.0.), Mesethmoid (.H., M.H."), Opisthotic (Op.0.),
Prefrontal (P.F'r.), Prootic (Pr.O.), Pterotic (Pt.O.—less
the fused dermal pterotic or squamosal), Sphenotic or
Postfrontal (Sp.O.—less the fused dermal sphenotic),
Supraoccipital (S.O.).
+The only definite cartilages in the Plaice’s skull are the ethmoid
cartilage (Hth.), inter-maxillary cartilage (J.M.C.) and Meckel’s cartilage.
The remaining cartilage is not of an independent character.
SEA-FISHERIES LABORATORY. 7
B.—Membrane bones which have become secondarily
incorporated into the cranium :—
i. Roof of Skull. Frontal (/’r.—less the fused lateral
line bone), Parietal (Par.).
11. Mouth. Ossifications in the mucous membrane—
Parasphenoid (Pa.S.), Vomer (Vo.).
(.—Lateral line ossicles and bones formed by the
modification of such:—Lachrymal (Lc.), Nasal (R.Na.),
Preoperculum (P.Op.), Squamosal (see pterotic—Pt.0.),
Suborbital chain, Supratemporal chain.
D.—Bones formed either within or in immediate con-
nection with the mandibular arch of the embryo:—
Angular (An.), Articular (Ar.—less the fused lateral line
ossicle), Dentary (1.—less the fused lateral line bone),
Maxilla (Mz.), Mesopterygoid (Ms.Pt.), Metapterygoid
(M.Pt.), Palatine (Pa.), Premaxilla (P.d/2.), Pterygoid
(Pt.), Quadrate (Qu.).
E.—Bones formed in connection with the hyoid arch
of the embryo :—
i. By modification of the upper segment of the arch
itself—Hyomandibular (Hm.), Symplectic (Sy.).
ii. By modification of the posterior branchiostegal
rays of the arch—Interoperculum (J.Op.), Operculum
(Op.), Suboperculum (S.O>p.).
F.—Compound bones, 7.e., cranial bones to which
ossicles or bones originally developed in relation to the
system of sensory canals have become secondarily fused to
their superficial surface :—Articular (Ar.), Dentary (D.),
Frontal (F'r.), Pterotic (Pt.O.), Sphenotice (Sp.0.).
We shall now proceed to describe the visceral skere-
ton proper, taking the hyoid arch first and the branchial
arches afterwards.
178 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
5.—Hyor Arcu* (Fig. 6).
3 | Ocular Side. | |
Uro-hyal (U.Hy.).t-—A short bony rod but ecar-
tilaginous in front and behind, and articulating with the
upper hypo-hyals and slightly with the first basi-branchial.
Hypo-hyals (./y.)—Two pieces, as in the Cod,
partly of bone and partly of cartilage and loosely articu-
lating in the middle line with the same elements of the
other side. The upper one is perforated in the middle,
thus giving a false impression as to the whereabouts of the
suture between the two.
Cerato-hyal (C./7y.).—A stout bar traversed in front
(anterior face) by a longitudinal groove, the texture of the
bone on each side of which running in different directions,
thus seeming to indicate that the cerato-hyal, as well as
the hypo- and epi-hyals, is either splitting or has been
formed by fusion. :
Epi-hyals (“p./y.). (eke doubler the lower piece
being entirely cartilaginous and the upper partly so. The
suture between the cerato- and upper epi-hyal is obscured
by an overgrowth of bone as in Micropterus,t but may be
seen on holding the hyoid bar up to the light.
*Tt is here necessary to explain the precise significance of the prefixes
basi- and hypo- as applied to parts of the visceral skeleton. The term basi-
can only be applied to a median unpaired ventral element, and the term
hypo- to the pair (2.e., one on each side), immediately succeeding it. Now
whilst these three elements may, and often do, exist side by side in any one
species, the basi- element may be absent, and a median unpaired ventral
piece formed by the two hypo- elements fusing together, the result being a _
secondary basi-segment. In the latter case the terms basi- and hypo- are
synonyms (and are used indifferently) ; in the former, they are not. -
+ The terms basi-hyal, glosso-hyal, ento-glossal and basi-branchiostegal
have also been applied to this bone in Fishes by different authors, and the
same terms, or some of them, have been applied to other elements in
higher Vertebrates. The synonymy is too complex to be discussed here,
+ Shufeldt, op. cit., p. 819, and fig. 32,
SEA-FISHERIES LABORATORY. 179
Inter-hyal (/.fy., figs. 5 and 6).—Possibly a sesa-
moid bone developed in the inter-hyal ligament and not
homologous with the other segments of the hyoid. This
bone is incorrectly called by some authors the stylo-hyal—
a term really a synonym of the pharyngo-hyal, represented
in most fishes by the hyomandibular. The inter-hyal of
the Plaice consists of a central bony rod with cartilaginous
extremities articulating with the hyoid and symplectic
and inter-operculum, as already indicated. Below the
attachment of the inter-hyal to the upper epi-hyal is seen
the prominence which is also connected with the inter-
operculum.
Branchiostegal Rays (7.F.).—There are the usual 7
of these rays, the first on each side meeting at their free
extremities, and being closely bound together by strong
fibrous connective tissue, appear to fuse. They are not all
attached at the same plane as shown in the figure. The
first 3 articulate with the cerato-hyal, the iast 4 at about
the junction of the 2 epi-hyals. The last, however, is
always attached to the upper or bony epi-hyal. The rays
have cartilaginous extremities, but otherwise consist of a
transparent milky coloured bone. ‘The first two cross and
he under the others in the living state.
Eyeless Side.
The hyoid bar is slightly shorter and not quite so
robust. The first pair of apparently fused rays are drawn
over to the eyeless side as shown in the figure. The most
tonspicuous difference is in the branchiostegal rays, which
are, except the first, uniformly shorter and not so curved.
The length and curve are faithfully represented in the
figure,
180 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
6.—Brancniat Arcuzs (Fig. 7).
Ocular Side.
Basi-branchial I. (2.5r.1)—A triangular bone, with
its apex wedged in between the upper hypo-hyals (see
fig. 6). At its base it articulates with basi-branchial IT.
and with the hypo-branchials of the first arch, but the
latter articulation is not obvious dorsally, the head of the
hypo-branchial fitting into a deep lateral socket formed by
basi-branchials I. and IT. According to Cunningham this
bone is in the Sole completely wedged in between the
upper hypo-hyals and does not articulate with the first
branchial arch at all.
Branchial Arch I.—''he epi-branchial (H.Br.') bears
a prominent tubercle on its anterior surface. The
pharyngo-branchial (P.#r.1) is a ‘slender bone which
articulates with the skull at the ventro-posterior margin
of the jugular foramen in the prootic immediately below
the hyomandibular cup. This somewhat curious connec-
tion with the skull also exists in the Sole according to
Cunningham, and in Sebastolobus according to Starks.
Basi-branchial Il. (B.Br.2).—An hour glass shaped
bone articulating in front with the basi- and hypo-
branchials of the first arch and behind with basi-branchial
IIl. and slightly with the hypo-branchials of its own arch.
Branchial Arch II1—The hypo-branchial is wide but
compressed dorso-ventrally. Where it articulates with
the second basi-branchial it sends down a prominent spine.
Another well-marked spine is borne on its anterior edge.
The cerato-branchial is longitudinally grooved ventrally.
As in the first arch, the epi-branchial bears a tuberosity,
but it is much more prominent on this arch. ‘the first
and last gill rakers are very small. The superior pharyn-
geal bone of the Plaice in medium-sized fish consists of
SEA-FISHERIES LABORATORY. 181
three pieces, which represent the pharyngo-branchials of
the three arches to which they belong. These pieces are,
however (and especially the anterior two), so closely bound
together that they may, as we have known them to do in
other forms, fuse up in old fish. The second pharyngo-
branchial (P.6r.?) is a stout laterally compressed bone
articulating with the third pharyngo-branchial posteriorly.
Tt bore five teeth in one row.
Basi-branchial III. (2.Br.*). A very thin laterally
compressed bone, apparently wedged out of existence by
the large hypo-branchials II. Its posterior extremity lies
under and is covered by the two hypo-branchials ITI.
Branchial Arch III.—The hypo-branchial is smaller
than in arch II., but the ventral spine is both larger and
longer, and articulating strongly with the same spine of
the other side forms a bony arch traversed by the ventral
aorta. ‘The anterior spine in hypo-branchial II. is absent.
The cerato-branchial is grooved ventrally as in arch IL.,
but more deeply. The epi-branchial bears two large
tuberosities at its distal extremity. The posterior of these
articulates with the pharyngo-branchial III. (P.Br.*), the
anterior by two strong ligaments with the epi-branchial
IV. The pharyngo-branchial (P.6r.*) bears a strong
process behind for articulation with the pharyngo-
branchial II., and bears eight teeth in two rows.
- Basi-branchial IY. (B.Br.*)—A very small nodule
of cartilage wedged in between the bases of arches III.
and IV. It is only connected with the fourth arch on the
ocular side, the basal elements of this arch on either side
meeting in the mid-ventral line. The morphological
value of this cartilage cannot be determined on adult
material. It is obvious that the branchial arches have
undergone reduction from behind forwards. Thus there
are only three segments in the fourth arch. Now it is
182. TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
also obvious that the basal segment of this arch (C.Br.*)
is serially homologous with the cerato-branchials, the
missing element therefore being the hypo-branchial.
Hence the fourth basi-branchial may represent either the
two vestigial hypo-segments fused together (a primary
basi-segment being absent) or it may have been formed
by the basi- and two hypo- elements fusing up.
Branchial Arch I¥Y—The cerato-branchial (C.6r. )
is slightly grooved ventrally. The epi-branchial (4.Br.*)
is a stout L-shaped bone, and is strongly connected with
the same segment of the preceding arch. The pharyngo-
branchial (P.Br.*) is small, and bore six teeth.
Branchial Arch ¥.—This is more reduced than any
of the other arches, and consists of a single bone on each
side in which there are practically no traces of asymmetry.
This is the inferior pharyngeal bone of Cuvier, and
appears to represent the cerato-branchial segment only of
the arch.* The inferior pharyngeals (£.Ph.) are stout
triangular-shaped bones separate dorsally but bridged in
front ventrally by a tract of cartilage. Two irregular
rows of teeth are borne on the pharyngeal surface, and in
the specimen now described there were 12 on the ocular
side and 14 on the eyeless. At the side and at the base of
the outer row are situated the replacing teeth, which be-
come functional as their predecessors wear away. |
Gill Rakers.— These diminish both in size and
number from before backwards. Their function is to pro-
vide a rough filtering apparatus for the water passing out
of the pharynx. ‘Their small size and number in the
Plaice is due to the nature of the fishes’ food. In those
fishes where the food might easily escape through the gill
slits (e.g. Clupea), the gill rakers are much longer and more
numerous. They are purely dermal and are not fused
«Cp. Cunningham, op. cit., and W. K. Parker, Phil. Trans., 1873 (Salmo).
SEA-FISHERIES LABORATORY. 183
on to the arches, the only connection between the arches
and the rakers being that in older specimens and in some
places the position of the raker is indicated on the arch by
a faint elevation. Their number and position, however,
was in the few specimens examined remarkably constant
and symmetrical, so that the following formula may apply
to either side of most individuals : —
eat | at) i)
| sie
Hy po-branchial 2 3 0 0 0
Cerato-branchial .... 5 6 7 6 0
Epi-branchial 3 1 0 0 0
Gill Rays.—The gill filaments are supported by series
of very delicate fragile gill rays fused together by their
bases like a comb, which it is hardly practicable to dissect,
but which are quite obvious in sections of the gills. They
radiate out from the branchial arches as usual, and occur
in pairs—one to each demibranch of the arch.
Eyeless SG. a
Branchial Arch I.—A1] segments slightly shorter and
not so robust, the hypo-branchial markedly so, nor is the
latter so deeply socketed into basi-branchials I. and II. as
on. the ocular side. The pharyngo-branchial also articu-
lates with the skull, but the depression in the skull with
which it is connected is deeper and more marked.
Branchial Arch II.—Practically no difference except
that the basi-branchial articulation is stronger on the
ocular side.
Branchial Arch III].—The segments are of the same
length, but are somewhat less robust. The ventral arch
transmitting the ventral aorta has been already described..
184 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
Branchial Arch IV¥.—The cerato-branchial is less
strong on this side, but on the other hand the epi-
branchial is larger. The cerato-branchial does not articu-
late with the fourth basi-branchial but with the corre-
sponding segment of the ocular side.
The Superior and Inferior Pharyngeals.—The asym-
metry in the number of the teeth is so strongly marked in
the mouth, where the ocular side is practically devoid of
them, that it is interesting to enquire whether its effect
has been felt as far back as the pharyngeal bones. In
the inferior pharyngeal the two sides are practically the
same, except that in the. specimen described the ocular
bone bore two less teeth. The left superior pharyngeal,
however, was appreciably the larger, and although it only
possessed an advantage of one in the number of teeth, the
teeth themselves were larger and capable of doing more
work. ‘This is doubtless due to the fact that in an animal
lying on its left side, its food, even in the pharynx,
naturally gravitates to the latter side. f
7.—VERTEBRAL CoLuMN.*
(Bigs 10011 a2 15, 14) ly eo:
The vertebral column of the Plaice may be divided
into a trunk and tail region only, distinguished in the
former by the presence of ribs and in the latter by the
haemal canal. Although the number of vertebre in the
column is subject to variation, it usually happens that the
first caudal vertebra is the fourteenth.
Each vertebra is markedly amphicoelous, the anterior.
and posterior faces being considerably scooped out in the
*The structure and development of the vertebral column of
Teleostean fishes has recently been studied by 8. Ussow (Bull. Soc. Imp.
Nat., Moscou, 1900, p. 175). Also previously in Amia and other fishes, by
O. P. Hay (Field Columbian Museum, Zool. Ser., vol. i., No. 1, 1895).
SEA-FISHERIES LABORATORY. 185
form of a cone, the two cones being connected in each
vertebra by the pin-hole notochordal canal (Canalis
dicentralis). As all these spaces are occupied by the
‘remains’ of the notochord, the latter is absolutely con-
tinuous from one end of the column to the other.
The following description is based mostly on a large
_ specimen of an extreme length of 52cm. In this animal
the neural spines were inclined as follows: 1, shghtly
forwards; 2, 3, 4, 5, almost upright; 6, shghtly forwards;
(-13, all slightly curved (with the convexity forwards)
and project more or less forwards; 14, largest spine (first
caudal) and projects slightly backwards; from 1-14 the
neural spines increase in length; behind 14 they all
incline backwards, the inclination becoming more and
more marked as the extremity of the tail is reached,
and they also decrease in length. With regard to the
haemal spines (of which the anterior ones are very much
longer than the corresponding neurals), the first 5 incline
shghtly forwards ; 4 is vertical; 5 looks backwards, and so
do the remainder, the tendency becoming gradually
exaggerated behind, and at the same time the spines
becoming shorter until they are about the same Jength as
the neural’spines. In the average specimen the posterior
haemals are slightly longer than the neurals (ep.
fig. 19). |
In the posterior third of the body the vertebral
column is situated about half way between its dorsal and
ventral edges. In front of this region, partly owing to
the slight upward curve of the column, but principally
owing to the increased length of the haemal over the
neural spines, the column is situated markedly nearer the
dorsal than the ventral edge. In the anterior third it
begins to bend down again slightly, and this is especially
noticeable in the first 4 or 5 vertebra, the result being
186 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
that the skull when attached to the vertebral column is
directed markedly downwards (see fig. 17).
The anterior notochordal space in most of the trunk
vertebrae (except the atlas) is perceptibly deeper than the
posterior, so that the notochordal canal is situated nearer
the posterior than the anterior face of the centrum. This
is more marked in some vertebre than in others. |
Atlas (figs. 10 and 17).—Body compressed from before
backwards. Notochordal canal (V.C.) much nearer dorsal
than ventral surface. Bears two large cartilage capped
facets (C.F’.) for articulating with the paroccipital con-
dyles, of which the left is perceptibly larger than the ~
right. ‘The anterior face of the centrum also articulates
with the single occipital condyle on the basi-occipital, the
connection of the skull with the vertebral column by
means of 3 condyles being therefore very strong. Unlike
all the other vertebrae, except about the last 5, the neural
arch of the centrum is only perforated by one foramen on
each side for the second spinal nerve. There is no trans-
verse process, and only one rib, which belongs to the series
of accessory ribs or intermuscular bones (A.#.'), and is
attached to its vertebra higher up than any of the others,
articulating at the junction of the neural arch with the
centrum (figs. 10, 17). As in all the other vertebre
(although the tendency is faint in the posterior caudals),
and as first described by Traquair, the atlas is markedly
asymmetrical, the neural spine being directed towards the
eyeless side. The asymmetry here is obviously an adapta-
tion to the habit of the animal in lying on its eyeless side.
Superficially this side is practically flat, whilst the ocular
side is convex. The asymmetry of the vertebre, there-
fore, tends to a flattening of the eyeless side and an arch-
ing of the ocular side (ep. figs. 11 and 13). The neural
spine itself is in the form of a rolled plate forming a hollow
SEA-FISHERIES LABORATORY. 187
eylinder, but the edges do not fuse behind. Except that
the eyeless condylar facet is larger than the ocular one
the asymmetry is not noticeable below the neural spine.
The centrum is overlapped by the large ill-defined anterior
zygapophyses of the 2nd vertebra, and itself bears faint
posterior zygapophyses at the bases of the neural arches,
whilst on the ocular side the latter sends back a
hook-like process which fits outsede the neural arch
of the second vertebra. This is the only trace of
the characteristic method of articulation of the vertebre
of the Cod.
| Second Vertebra (fig. 17, V.?).—The neural arch is
perforated on each side by two foramina for the roots of
the third spinal nerve, but the bridge of ‘bone separating
the right pair is extremely slender. The large irregular
anterior zygapophyses are asymmetrical, that on the eye-
less side being much the larger. The neural spine is also
asymmetrical as in the atlas, but the asymmetry extends
down on to the neural arch. A small pointed transverse
process is present, with a long accessory rib (A.R.?)
strongly attached to its base much lower down than the
attachment of the first intermuscular bone. Both the
centrum and neural arch bear post-zygapophysial facets
not shown on the eyeless side.
Third Vertebra (fig. 17, V.2)—Whole of the vertebra
markedly asymmetrical, being more strongly developed
on the eyeless side in every respect. Neural spine and
spinal canal arch to the left. Anterior and posterior
zygapophyses more strongly marked on the same side.
The centrum not only bears a strengthening ridge (S.R.)
which is much stronger on the eyeless side, but is itself
more bulky on that side, so that the notochordal canal is
eccentric in position. The transverse processes, like all
those succeeding them, and as already described by
188 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
Traquair (pp. 285-6) are asymmetrical—that on the eyeless
side having a more ventral origin and inclination; but
the asymmetry of these processes is not specially marked
in this vertebra, and may indeed be practically confined
to vertebrae 5-12 inclusive. The accessory rib (A.J?.?) is
attached nearer the base of the transverse process on the
eyeless side.
Fourth Vertebra.—Much the same as 3, except: (qa)
two moderate strengthening ridges are present on the eye-
less side, and one on the ocular side with a deep cleft on
each side of it; (6) a true rib is present, and is attached
to the posterior surface of the transverse process half way
between its extremity and the attachment of the accessory.
rib. From this vertebra onwards the transverse ,:rocesses
increase in length and the true ribs (which rapidly in-
crease in length up to the 7th, the longest [see fig. 18],
but rapidly decrease in length after this) gradually
approach the tip of the transverse process, until at about
the 8th or 9th vertebra they are obliquely attached to the
tip. The accessory ribs, which from the 2nd to the 9th
inclusive vary very little in length, are also attached in a
backwardly descending line until about the 10th or 11th
vertebra, after which, just as they begin to decline in size,
they rise rapidly on the vertebra (cp. fig. 18), until pos-
terior to the 14th or Ist caudal vertebra they are doubtless
represented by the serially homologous tubercles situated
on, and fused to, the centrum, and forming pseudo-trans-
verse processes.
Fifth Yertebra.—Neural spine almost flat and only
curved backwards slightly at the lateral edges. Asym-
metry slightly increasing.
Sixth Vertebra.—Only one strengthening ridge on
eyeless side and two on ocular. Asymmetry of centrum
and transverse processes strongly marked, but more so
SEA-FISHERIES LABORATORY. 189
anteriorly than posteriorly. The post-zygapophyses pro-
ject slightly backwards as distinct processes.
Seventh Vertebra.—One strengthening ridge on each
side, but slightly cleft into two. Neural spine more com-
pact and solid. Posterior zygapophyses are now distinct
tubercles projecting backwards from about the mzddle of
the neural arch. The anterior zygapophyses are, as
hitherto, except in the first 3 or 4 vertebra, triangular
processes projecting forwards from the base of the neural
arch. .
Kighth Vertebra (fig. 11)—'wo moderate and one
weak strengthening ridge on the eyeless side and three of
about the same character on ocular side. Posterior
zygapophyses as in 7. Anterior zygapophyses much
stronger on eyeless side. Neural spine for the most part
consists of two hollow tubes placed side by side end con-
nected by a narrow bridge of bone.
Ninth Vertebra.—Two well marked strengthening
ridges and rudiment of another on eyeless side and two on
ocular side. ZAygapophyses getting weaker. Neural arch
slightly, and neural spine markedly, asymmetrical, but
the centrum is almost symmetrical with the notochordal
canal in the centre. |
Tenth Vertebra (fig. 18, V.10)—Two strengthening
ridges on eyeless side and three on ocular. Zygapophyses
somewhat reduced, and not much difference between those
of the two sides. Centrum slightly asymmetrical and
neural and transverse processes still obviously so, but the
tendency is now on the wane. The accessory and true
ribs of this vertebra are the longest of any. Behind both
decline in length.
Eleventh Vertebra (fig. 18)—Three strengthening
ridges on eyeless and two cn ocular side. Asymmetry
slightly less marked than in preceding vertebra. Zygapo-
190 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
physes slightly weaker and more symmetrical. The trans-
verse processes are now increasing in width from before
backwards, and bear a slight elevation to which the
accessory rib is attached.
Twelfth Vertebra (figs. 12 and 18).—Strengthening
ridges as in 1]. Asymmetry slight. Post-zygapophyses
faint and practically symmetrical. Transverse process
proximally very wide from before backwards. Neural
spine more consolidated, but still consists of 2 bony tubes
placed side by side.
Thirteenth Vertebra (fig. 18).—Three strengthening
ridges on eyeless side, and two on centrum and one on
transverse process on ocular side. Symmetry as in 12.
Transverse processes only very slightly asymmetrical.
Accessory rib rudimentary and attached to a prominent
elevation near base of transverse process (A.R.13). Last
vertebra to bear free ribs of either series. Behind the
transverse processes and true ribs are converted into the
haemal arch and spine. This gradual conversion, and the
homology of the parts, is well shown in figure 18. Zygapo-
physes as in 12. ‘Transverse processes very wide from
before backwards.
Fourteenth Vertebra (figs. 13 and 18)—The first
caudal vertebra. Three strengthening ridges on each
side. The neural and haemal spines are the longest of
any, and both incline slightly backwards and towards the
eyeless side. The neural spine, which is only about two-
thirds the length of the haemal spine, is somewhat com-
plex, and contains three longitudinal cavities, all of which
open posteriorly at the top of the spine. The left anterior
zygapophysis is much more prominent than the right,
whilst the post-zygapophyses are feeble and no longer
obvious as projections from the posterior border of the
neural arch, ‘The posterior notochordal space, unlike
SEA-FISHERIES LABORATORY. 191
those of the trunk vertebrae, is deeper than the anterior,
and hence the notochordal canal is thrown further for-
wards. The centrum is markedly asymmetrical, being
larger on the eyeless side. The projection at the side of
the centrum which possibly represents the remains of the
accessory rib and its basal tubercle (A.2.*), with which it
is serially homologous and to its present position on the
centrum it has been gradually ascending from the trans-
verse process, 1s larger and has a more ventral inclination
on the ocular than on the eyeless side. Below the centrum
are situated the haemal arch with its canal and the haemal
spe. The latter is a thin curved laminate bone with the
concavity directed forwards, and strengthened behind by
two thin longitudinal ridges. In front it bears a wide
longitudinal recess (Rec. Awv.') which lodges the large first
axonost of the anal fin.
The following points of interest may be noted in the
caudal vertebre. Behind the fourteenth or first caudal
vertebra the vertebral column has a much more uniform
structure, except that the first few caudals represent inter-
mediate stages between the characters of the 14th and
those of a typical caudal vertebra (cp. figs. 18 and 19).
The asymmetry extends right down to the extremity of
the column, but is only very slightly developed in the last
few caudals and in the epurals and hypurals of the caudal
fin.
Neural and Haemal Spines.—As we pass back the
spines get more simple in structure, shorter, und project
more posteriorly. Both spines are, however, always fur-
rowed longitudinally for the reception,of the large verti-
eal sheet of ligament connecting them with each other.
The structure of the last vertebra will be described in the
section on the caudal fin.
192 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
Foramina of Spinal Nerves.—All the neural arches
except that of the atlas and usually about the last 5 are
perforated by two foramina on each side for the exit of the
spinal nerves (figs. 12, 14, 17, 18, 19). The ventral
foramen is usually situated a little anterior to the dorsal
one. Of the last 5 caudals the last is not perforated at
all, and the preceding 4 have only one perforation on each
side (fig. 19). The last vertebra, as of course in all the
other caudals, has both a neural and a haemal canal.
Zygapophyses.—As shown in fig. 18, the anterior
zygapophyses decline after about the 14th vertebra, and
about the last 7 caudals have practically no zygapophyses
at all. After the 15th the pre-zygapophysis is much re-
duced, and only very slightly overlaps the vertebra in
front or does not do so at all. Hence behind this vertebra
the post-zygapophyses are entirely lacking.
Strengthening Ridges.—These are disposed much the
same as in the trunk vertebrae, except that in the hinder
caudals there is a tendency for the ridges to be collected
into one strong ridge situated mid-laterally on the
centrum. This, however, does not obtain in all the pos-
terior caudals (cp. fig. 19).
Notochord.—All the caudals have a notochordal canal
except occasionally the last. The centra of the most pos-
terior vertebre are always less ossified than those in front,
and hence the notochordal spaces are larger. The urostyle
is deeply excavated also, but the excavation extends
straight backwards and does not turn up.
Accessory Ribs. The tubercles which have been
identified as the remains of the accessory ribs are well
marked on the anterior caudals, but diminish backwards
and are practically absent on about the last 12. In the
anterior caudals they occupy the position of the transverse
processes of the trunk vertebra.
SEA-FISHERIES LABORATORY. 193
8.—CaupaL Fin anp EXTREMITY oF VERTEBRAL COLUMN
(Figs. 14, 15 and 19).
The caudal fin when first dissected appears to be
diphycercal, -but the asymmetrical articulation of the
second hypural bone (Hp.2) at once establishes its
heterocercal character. Nevertheless the caudal fin. of the
adult Plaice is one of the most completely masked hetero-
cercal or homocercal fins on record, and is hence of some
interest. The termination of the vertebral column is
peculiar, as in place of an upturned tapering bony
“urostyle ’ formed by the ossification of the free extremity
of the notochord, there is found an expanded fan-shaped
plate which, with the second hypural, gives articulation to
the greater part of the caudal fin rays. The proximal
stout vertebra-like body articulating with the last true
vertebra may possibly represent another vertebra, but it is
not constricted off in Plaice from 15 mm. upwards, and in
the absence of earlier developmental evidence is here
described as the base of the urostyle. - Dissection of young
plaice of a length of 45mm. shows the vertebral column
terminating as above described, but similar preparations
of still smaller forms of 15-17mm., where the notochord is
yet unossified, prove conclusively that the fan-shaped plate
is formed by the fusion of the upturned extremity of the
notochord with a separate hypural bone (fig. 15, {.3),
and hence the plate (U. + Hp.3) of the adult is a com-
pound bone representing the urostyle and a third hypural
fused together. It will be noticed in fig. 15 that the free
surface for articulation with the fin rays is afforded exclu-
sively by the third hypural—the urostyle taking no part
in it. Apart from the independence of the urostyle and
third hypural the tail of a form of the above length shows
no essential difference from that of an adult, beyond those
Q
194 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
differences incidental to its stage. The above description
should be compared with the apparently similar one in
Sebastolobus (Starks, op. cit.), and with the very dissimilar
one occurring in the herring.*
If the last distinct vertebra (fig. 14, V.43, 19, V.42)
be now examined, it will be seen that the neural spine
(W.S.43, 42) resembles the haemal spine (H.S.30, 29) in
structure, but that both are peculiar. Each consists of a
partly cartilaginous shaft behind and a thin laminate ©
portion in front. The posterior shafts so closely resemble
the succeeding epural and hypural bones respectively as
to suggest that an epural above and an hypural below have -
fused on to the laminate portions, which latter are un-
doubtedly similar to and perhaps represent the neural and
haemal spines in front. As, however, we have no positive
evidence of such a fusion, the spines in question are here
described as simple neural and haemal spines.
Wedged in between U + Hp. 3 and N.S. 43 (fig. 14)
are two partly cartilaginous spines (Yp. 1 and 2) which
are closely connected by ligament with each other and
with the last neural spine, but which are not sufficiently
long proximally to reach the vertebral column. The
gradual increase in length of these spines as the animal
grows older suggests that they may in senile forms become
connected with the vertebral column. That they develop
in the same way as the neural spines seems certain,
although there are no vertebre ostensibly belonging to
them. One is appreciably larger than the other, and there
is a big gap between the second and U. + Hp. 3. They
represent the epural or epiural bones of other authors.
The second hypural bone (Hp. 2) is of the same shape
and structure as the upper piece (U + Hp. 3), both being
cartilaginous distally and strongly ossified proximally.
* Duncan Matthews, Fishery Board, Scotland, Report v., 1886,
SEA-FISHERIES LABORATORY. 195
It articulates as shown in fig. 14 with U + Hp. 3 above
and in front, the latter articulation making the two ex-
panded tail bones unequal. The first ostensible hypural
(Hp. 1) is a wedge-shaped bone of the same structure as
the 2nd, but much smaller. It is closely attached by hga-
ment to the last haemal spine, but proximally does not
reach the vertebral column.
Hach bone in the tail giving articulation to fin rays
bears a thin terminal cartilaginous epiphysis (cp. fig. 14).
As in the other fins there is a pad of sub-cartilaginous
tissue intercalated between the bones of the vertebral
column and the proximal ends of the fin rays. This, as
before, is embraced by the diverging halves of the rays
(Ff.R.). The number of the latter in the caudal fin varied
in the specimens examined around 20—sometimes more
and sometimes less. What possibly may be regarded as
the typical condition both as regards number and places
of articulation is represented as follows (cp. fig. i4):—
Shaft of last neural spine, 1; Epural 1, 1; Epural 2, 2;
Hypural 3, 6; Hypural 2,6; Hypural 1, 3; shaft of last
haemal spine, 1; total, 20.
Hach fin ray is of the same structure as those of the
pectoral and pelvic fins, with the exception that there are
no articular processes connecting the individual rays with
their neighbours, each ray in the caudal fin, therefore,
being independent of those immediately above and below
it. With the exception of about the three most dorsal
and ventral, each ray bifurcates distally, but does not split
up further to form a brush as happens in the caudal fin
rays of the Sole according to Cunningham.
9.—Dorsat Fin (Figs. 17 and 19).
The dorsal fin commences very far forwards in the
pseudo-medial line, and in the specimen on which the
196 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
present description is based, which measured 52cem., the
base of the first dorsal fin ray was only 6mm. from the
posterior narial aperture of the eyeless side, z.e., well in
front of the cavity of the brain. |
As in the paired and caudal fins all the fin rays con-
sist of two pieces. Hach fin ray is connected with two
further skeletal pieces termed by Cope,* Baur,t and
Smith Woodward the baseost and axonost, by T. J.
Parker§ pterygiophores, and by Bridgel| radial elements.
The axonost has hitherto been called ihe interspinous
bone, on account of its position between two neural spines.
The terms baseost and axonost are adopted in this work,
and the precise connections between these two elements and
the two pieces forming a fin ray will be described below. In
the meantime it may be remarked that usually one or two
axonosts are found between two adjacent neural spines in
the dorsal and anal fins of the Plaice, whilst the baseost
is always situated between and attached to the heads of
two adjacent axonosts. The two halves of the fin ray
diverge proximally and tightly clasp the baseost (ep. fig.
16). This mechanism was first described by T. J. Parker in
Regalecus, and has since been described in the Plaice by
Bridge. Each axonost, even in old specimens, consists
usually of a bony cylinder filled with cartilage. The head
is always hollow, and is filled up with a triangular plug
of cartilage (fig. 16). |
The first dorsal fin ray has no baseost, but its halves
diverge as usual and embrace the head of the first axonost
with only a small sub-cartilaginous pad between. It 1s
also asymmetrical, the ocular half being slightly the
longer.
* American Nat., 1890. + Jour. Morph., vol, iii.
t Catalogue Fossil Fishes, British Museum, and Vertebrate
Paleontology.
§ Trans. Zoo], Soc., vol. xii Journ, Linnean Soc., vol, xxv ~
SEA-FISHERIES LABORATORY. 197
‘The axonost lettered 1 + 2 in figure 17 is also asym-
metrical, its head inclining to the eyeless side. As this
bone supports two fin rays (unlike any other in the body,
except the huge axonost 1 of the anal fin), it was carefully
-examined in a very large plaice, and was there seen to
present indications of three pieces, two of which possibly
correspond to what would represent the first and second
axonosts locked together, whilst the third is the partly
cartilaginous proximal shaft wedged in between them and
connecting them with the skull. If this interpretation of
the first apparent axonost be correct, the first baseost
(Bs. 1) will be situated between two axonosts as it should
be, and not present an anomaly only found elsewhere in
the skeleton of the plaice at the anterior extremity of the
anal fin. Posteriorly near the head of axonost 1 + 2 isa
recess into which fits baseost 1 for the second fin ray.
Below this recess is a prominent projection which gives
articulation to baseost 2 for the third fin ray. The second
fin ray is asymmetrical, the ocular half being the longer.
The third -axonost and fin ray are practically sym-
metrical. The head of this axonost forms a cone, the
second baseost articulating in front and the third behind.
Below the head the axcnost bears leafy projections in
front and behind.
In the fourth axonost the leafy projections above are
exaggerated and the shaft is reduced to a median ridge on
each side of the axonost. This form of the axonost, 2.e.,
with a median spine on each side and thin laminz in front
and behind, represents the typical structure of an axonost,
and is admirably adapted for the muscles of the fin ray
inserted into it. As described by Cunningham (pp. 47-48)
in the Sole, each fin ray has six muscles, of which there
is one on each side (the “right and left abductors’) for
deflecting the fin ray to the right and left of the median
198 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
plane and which are not connected with the shafts of the
axonosts, whilst the other four (the “ elevators and depres-
sors’) are arranged 2 on each side, the anterior right and
left pair arising from the anterior surface of the fin ray
and being inserted into the lamina on the shaft of the
axonost in front of the median spine, the posterior pair
arising from the posterior surface of the ray and being
inserted into the posterior lamina. The latter muscles
elevate and depress the fin ray in the median plane.
If the dorsal surface of the cranium cf a plaice be
examined, there will be noticed in the pseudo-mesial plane
a longitudinal trench-like depression which passes back-
wards in a slight sigmoid curve from left to right on the
left frontal and supraoccipital. This depression (see fig.
1) is connected with the extension forwards of the dorsal
fin over the roof of the cranium. Into it fit usually
axonosts 6, 7, 8, whilst the axonosts in front of these,
though too short to actually reach the cranium, are con-
nected with the depression by means of ligaments.
Behind the attachment of the eighth axonost, the ceciput
suddenly shelves down, and in this depression, 7.e.,
bounded in front by the reduced occipital spine and
behind by the first neural spine, are situated the two suc-
ceeding axonosts (9 and 10). Behind the 10th the
axonosts become related to the neural spines as usual.
The posterior extremity of the dorsal fin is only note-
worthy in two respects: (a) in the presence of 4 axonosts
between neural spines 36-37, the largest number found
between any two succeeding neural or haemal spines,
excepting the anterior extremity of the anal fin; (0) the
last fin ray (71) articulates directly with the axonost (70)
without the intervention of a baseost. The last four
vertebre have no connection either with the dorsal or anal
fins. In the specimen on which the above description was
SEA-FISHERIES LABORATORY. 199
founded the last fin ray was characterized by its sigmoid
curve and horizontal position. These features were doubt-
less anomalies.
10.—Awat Fin (Figs. 18 and 19).
The mechanism of the fin rays and their skeletal
supports is the same as in the dorsal fin. The axonosts
are, however, perceptibly longer than those of the latter
fin, and they are sometimes called interhaemal bones to
distinguish them from the interspinous elements. The
structure of the anal axonosts is the same as that of the
dorsal ones.
The anterior extremity of the anal fin is interesting
in many ways. ‘The posterior boundary of the body cavity
is supported by a very stout bone which curves downwards
and forwards from its roof, and terminates in a point
behind the anus. Above it fits into a deep recess borne
on the anterior face of the haemal spine of the first caudal
vertebra (fig. 13, Rec.Av.'). The ventral point, to an
extent indicated in fig. 18 by a ring, is in dead specimens
almost invariably found perforating and projecting freely
through the skin behind the anus. It seems highly im-
probable that such a pathological condition can obtain
during life, but the skin covering the point must be very
thin.* This bone, in the lack of any evidence as to its
development, is here called the first axonost, but it is
certain that it is more than this. In no other part of the
body is a baseost situated anywhere but between two
* We are now certain that the point does not perforate the skin during
life, but that the latter is somewhat easily ruptured when a plaice is
handled_and allows the point to protrude. Also that the protrusion in dead
specimens is due to contraction following on preservation. To make use,
therefore, of this so-called external ‘‘ anal spine’’ in classification, as has
hitherto been done, is absurd. Since this was written, we note that Kyle
arrives at the same conclusion.
200 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
axonosts.- As therefore the first axonost of the anal fin
supports two baseosts completely and another partially, it
follows that it has been formed of at least 5 axonosts fused
together; but, as before remarked, we have no direct
evidence of this.t The first baseost is situated in a de-
pression and the succeeding two on an elevation on the
postero-ventral surface of the first axonost, whilst the
second axonost is closely opposed for its whole length to
the same surface. The axonosts 3 to 7 fit by their tips
into a posterior longitudinal furrow borne on ihe first.
It is obvious that, as the first axonost is situated between
vertebre 13 and 14 and axonost 7 lies in front of the
haemal spine of the latter vertebra, axonosts 1 to 7 and fin
rays 1 to 8 are situated in a space bounded morphologi-
cally by two adjacent vertebre. As previously men-
tioned, in only one other part of the body are as many as
4 axonosts found in a corresponding position.
The posterior extremity of the anal fin presents no
features of special interest except that the last fin ray
articulates with the last axonost without the intervention
of a baseost.
The mechanism of the fin ray has now to be described
(see fig. 16). Each ray consists of two longitudinal
distally segmented pieces (/’.R. a, 6) held together by a
transverse ligament (/’.R. c). Proximally these two
pieces diverge and embrace the baseost (Bs.), and also to
a limited extent the axonost (Aa.). The articular surfaces
bear pads of a peculiar kind of soft cartilage (47.C.). Hach
half of the fin ray is connected with the baseost by a stout
ligament (F.R. d). Now the only connection between the
+ Whatever doubts may arise on this point willbe settled by a reference
to the condition in Solea, as described by Cunningham; and in Rhombus,
as described by Kyle. .
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SEA-FISHERIES LABORATORY. 201
baseost and axonost is a very slight non-ligamentous one,
and hence the fin ray and baseost are only held down in
the soft cartilage cup at the head of the axonost by the
elevator and depressor and right and left abductor muscles
(F.R. e) of the fin ray. The result is that the fin ray and
baseost are capable of being moved on the axonost in any
direction. - The axonosts are held in position by two liga-
ments: (a) by a longitudinal vertical ligament which
keeps the axonosts at their correct distances from each
other and separates the right and left series of the fin-ray
muscles; (b) by transverse ligaments (Aw. a) which keep
the axonost from moving from side to side. The head of
the axonost contains a triangular plug of typical hyaline
cartilage (Aa: b) as before mentioned. The whole appa-
ratus is somewhat asymmetrical as shown in the figure.
The attached table, based on the examination of a
52em. plaice, has been drawn up to show the number,
position, and precise relations. of the ribs, neural and
haemal spines, and skeleton of the dorsal and anal fins.
The specimen had 42 vertebre (cp. figs. 17, 18 and 19).
The division into regions is somewhat arbitrary, since for
example the boundary between the cranial and occipital
regions is along the axis of fin ray 9 and baseost 8, 2.e.,
between axonosts 8 and 9. Jn the anal fin the axonosts 1
to 7 are situated morphologically between vertebre 15 and
14 (ep.. fig. 18), and hence, at this region (as
indicated by the line) the correspondence between the two
regions of the table has no morphological value. Behind
this ambiguous region (ze. behind and including
vertebre 14) it will be noticed that although there is a
very wide disagreement in the disposition of the fin skele-
ton above and below the vertebral column, yet the
numbers of the fin rays are practically the same, 7.e., 45 in
202 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
the dorsal fin and 46 in the anal. Thus, although the
physiological result is the «same, the means by which it
has been arrived at do not exhibit a-serial agreement.
11.—PrctoraL GIRDLE AND Fin (Fig. 8).
Clavicle (C/.).—A large curved bone. The upper part
or handle is the stoutest and bears a thin lamina behind
for the articulation of the post-clavicle. The cuter face
dorsally is flattened for the reception of the supra-clavicle.
Below, the clavicle is connected in the mid-ventral line
with the clavicle of the other side by a long symphysis.
Post-clavicle (P.C/.)—A long thin curved bone
articulating above by its upper enlarged extremity with
the clavicle, and for the rest lying freely in the superficial
muscles under the pectoral fin. Its position is partly indi-
cated externally by a scar on the skin. In one specimen
examined the post-clavicle was double, the two pieces
uniting, however, at the clavicular articulation. Accord-
ing to Cunningham’s figure this bone is not present in the
Sole. .
Supra-clavicle (S.C7.).—A small triangular bone, thin
below but stouter above. Ventrally it overlaps the
clavicle, and above it is overlapped by the post-temporal.
Its upper extremity bears a prominent cartilaginous knob,
which fits into a deep pit on the inner face of the post-
temporal.
Post-temporal (/?.7'y.).—This bone, sometimes called
the ‘“‘ supra-scapula,”’ differs from the usual Teleostean
type in so far as there are only moderate indications of the
forking, and there is only one direct articulation with the
skull. Above and in front there is a prominent articula-
tion (representing the upper or epiotic limb of the post-
temporal) with the pterotic and epiotic. Somewhat below
this, and also in front, is a moderate elevation (represent-
SEA-FISHERIES LABORATORY. 208
ing the lower or parotic limb), which is connected by a
ligament with the skull at the region of the junction of
the pterotic and opisthotic. In the Sole, according to
Cunningham, the forking is more marked, and the lower
limb is connected with the opisthotic only. The post-
temporal in the Plaice is tunnelled by the lateral sensory
canal.
Scapula (Sc.)—A thin plate, which for some time
remains largely cartilaginous, but which is completely
ossified in very large fish, having an oblique shelving
articulation with the clavicle. Almost one-half of its
outer surface lies internal to, and articulates with, the
clavicle. It is perforated by the usual scapular fenestra
for the R. ventralis of the first spinal nerve.
Coracoid (Co.).—Consists of two parts which are, how-
ever, continuous: a dorsal part (corresponding to the
meso-pre-coracoid of W. K. Parker*), which calcifies late,
is thicker than the ventral part, and gives articulation to
fin rays; a ventral thin laminate part (the coracoid of
Parker) which calcifies early and projects downwards for
some distance as a ventral spine. Owing doubtless to the
long articulation with the clavicle the connection between
these two bones is here a simple and not a shelving one as
is the case with the scapula. The ventral part of the
coracoid is absent in the Sole according to Cunningham’s
figure.
Brachial Ossicles.—l'hese are doubtless absent, but
may be represented by three structures: (1) a wedge-
shaped piece of cartilage attached mostly to the coracoid
but partly also to the scapula-(cp. fig. 8)—this is present
in the Sole according to Cunningham’s figure; (2 and 3)
two sub-cartilaginous pads, one of which works over the
free surface of (1), and the other the free surface of the
* « Shoulder Girdle.’’ Ray Society, 1868.
204 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
scapula (cp. fig.). It is these pads that really give articu-
lation to the fin rays, and are in fact interposed between
the extremities of the fin rays and the scapulo-coracoid.
Judging from the analogy of the other fins there may only
be one pad normally present in the pectoral fin (ep. pelvic
and caudal fins).
Fin Rays (/’./.)—There were eleven fin rays in the
pectoral fin of the specimen now described. Hach ray
consists of two pieces enclosing a central core of soft
tissue, as commonly occurs among Teleosts. Hach ray is
completely segmented for the greater part of its length, so
that on maceration it falls into a number of very small
pieces. ‘The two portions of the ray diverge at the
scapulo-coracoid. articulation and embrace its sub-
cartilaginous pad as already described. Tach portion also
sends down an articular process, and the two of each fin
ray clasp the ray immediately below it (ep. fig.), thus
giving a rigidity to the fin it would not have were the fin
rays independent of each other. Three of the rays were
bifurcated at their free extremity in this specimen, and
where this obtains both halves of the ray spht, the bifur-
cation not being due to the two halves diverging.
“Inter clavicle” (/.C7.).—This bone, of questionable
homology. is described last, as it is doubtful what claim |
it has to the name now given it. It is a median V-shaped
bone—one lmb of the V being horizontal and the other
projecting forwards and downwards. It is situated in the
muscular cone.of tissue passing forwards to the hyoid
arch: from the clavicle in the middle line between the
basal portions.of the branchial arches. The horizontal
limb is connected anteriorly by four long stout ligaments
with the inner face of the lower hypo-hyal of each side—
two lgaments passing to each hypo-hyal.: Behind it is
connected with the clavicle. The arms of the V are
SEA-FISHERIES LABORATORY. 205
densely calcified, and so is that portion of the lamina at
the junction of the arms. The remainder or posterior
part of the bone consists of a very thin plate or lamina.
The “ inter-clavicle ” is called by Owen, Huxley and other
anatomists sometimes the uro-hyalt and sometimes the
basi-branchiostegal, and it is asserted by Cunningham
that these names cannot correctly be applied to it. The
term (2.e., “ jugular’) used by Cunningham is, however,
itself inadmissible, since it is liable to be confounded with
the jugal or with the jugular plates of “ Ganoids ’’—with
the former of which it can have no possible connection.
In the Sole, according to this author, it is applied directly
to the clavicle and first basi-branchial, and in this differs
markedly from the Plaice, where it is placed some dis-
tance from both these bones. Its position in the Plaice
relative to that of the clavicle is correctly indicated in
fig. 8, and it is somewhat further removed from the hyoid
arch. Hence, whatever its position in other Teleosts, in
the Plaice it is directly connected neither with the clavicle
nor with the hyoid. In Sebastolobus according to Starks,
and in Micropterus according to Shufeldt, what seems to be
‘
the undoubted homologue of the “ inter-clavicle ” articu-
lates with the hyoid arch and 1s called by these authors the
“uro-hyal.” Cunningham’s objection to this term, how-
ever, seems to be valid, and hence the provisional name of
“inter-clavicle ”"—a bone with which it may not unrea-
sonably be identified. On the other hand its connection
in other forms with the hyoid arch indicates that it may
have been derived from branchiostegal rays, in which case
it may conceivably be homologous with the jugular
+The supposed resemblance to the uro-hyal of the bird doubtless
suggested this homology. Kyle has recently revived this name for the
bone, but does not seem to be aware that the terms uro- and glosso-hyal
are too often used as synonyms to justify any separation now. In any
case, we consider the term uro-hyal quite inadmissible,
206 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
or gular plate of Amia. This, however, is so very
problematical that to prevent confusion, Cunningham’s
term must be rejected.
12.—Pertvic GirDLE anpD Fin (Fig. 9).
Innominate or Pubic Bone (/n.).—Situated just
behind the ventral extremity of the clavicle. It is
strongly connected by its dorsal extremity with the inner
face of the clavicle opposite the upper boundary of the
clavicular symphysis. It is also connected more or less
for the whole of its length, and especially ventrally, with
the innominate of the other side. In medium-sized plaice
it consists of three pieces, but the tendency is for the lower
extremity to calcify. The dorsal piece (1) is the largest
and consists of a fairly strong posterior rod, produced
below into a ventral spine, to which is attached in front a
thin bony plate. Ventrally there is an obvious piece of
cartilage (2) which gives attachment to a terminal car-—
tilaginous epiphysis (3), which in its turn supplies the |
surface over which works the sub-cartilaginous pad giving
articulation to the fin rays.
Fin Rays (/.R.).—Articulate directly with the
innominate except for the intervention of a sub-car-
tilaginous pad as in the case of the pectoral fin. The fin
rays here resemble those of the pectoral fin, and consist
each of two pieces, but the latter diverge more proximally,
and the posterior articular processes are terminal instead
of sub-terminal as in the pectoral fin. The fourth and
fifth of these processes, further, projected backwards and
downwards instead of straight backwards as with the
others (cp. fig.). None of the fin rays bifurcated, and
there were the normal six of them in the pelvic fin of the
specimen now described,
SEA-FISHERIES LABORATORY. 207
C.—THE BODY-CAVITY AND ITS VISCERA.
We propose describing under this section the alimen-
tary canal, the digestive and ductless glands and the renal
organs, leaving the reproductive organs to be described
in Section G.
1.—THE CaLtomic SPACES.
The derivatives of the embryonic celom are (1) the
body cavity, (2) the pericardium, (3) the cavities of the
ovaries (in the female), and (4) the cavity of the ureters.
The body cavity is bounded dorsally by the kidney, which
hes underneath vertebree 2 to 14, anteriorly by the pos-
terior fibrous wall of the pericardium, the lower portions
of the clavicles, the innominate bones and the muscles of
both lmb girdles, and posteriorly by the 1st haemal spine
(7S. 1, fig. 21) and the 1st axonost (1. Az.). It contracts
ventrally, so that only a small region surrounding the
anus is bounded by the ventral body wall. The lateral
body walls are strongly muscular, and the parietal peri-
toneum is deeply pigmented. There is no posterior exten-
sion of the body cavity on either side, such as occurs in
the Sole, and is stated by Kyle to exist also in the Plaice.
The nature of the cavities of the ovaries and renal
organs is best considered with the description of those
organs.
2.—THE ALIMENTARY CANAL AND ITs GLANDS.
The alimentary canal may be conveniently divided
into the following regions: csophagus, stomach, duo-
denum, intestine and rectum. (isophagus and stomach
are distinguished from each other and from the rest
of the alimentary canal by the differentiation of the
mucous membrane, The duodenum is the proximal
908 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
portion of the post-pyloric intestine which bears the
pyloric czeca and receives the bile and pancreatic ducts.
There is no essential difference between intestine and
rectum, but it is convenient to distinguish the terminal
portion of the alimentary canal from that nme
preceding it. ) i oe
The appearance presented i the viscera cn vpening
the body cavity of a large plaice from the ocular side
varies considerably with the condition of the reproductive
organs and with the sex. Fig. 20, pl. V., represents the
relations of the viscera in a “‘ripe’’ and mature female.
The great increase in volume of the ovaries has crowded
the greater portion of the intestine towards the dorsal
part of the body cavity; the duodenum is pressed for-
ward; the rectum being more fixed than the rest cf the
post-pyloric intestine is not much displaced: the stomach
occupies nearly its normal position. Fig. 21 shows the
condition of the viscera in a mature female which has just
spawned. ‘The greater portion of the intestine kas been —
removed, however, in order to display the deeper viscera.
It would form two S-shaped loops overlying and hiding
most of the structures indicated in the figure.
The Gsophagus is very short, and almost immediately
on entering the body cavity expands into the stomach.
Its walls are very thick and are composed almost entirely
of a transversely disposed layer of striated muscle fibres.
The external longitudinal muscle layer is thin, and
appears to consist of unstriated fibres. The mucosa con-
sists of a layer of columnar cells crowded with “ goblet ”
cells. As observed in the dead fish, the lumen of the
cesophagus is greatly reduced, though it is evident from
the nature of the food that it is capable of considerable
expansion.
The layer known as the muscularis mucosze does not
SEA-FISHERIES LABORATORY. 209
appear to be present in the intestine of the plaice. Nor is
the peculiar “stratum compactum”’ of the submucosa
which Oppel has described in some other fishes certainly
present.
The Stomach (fig. 21) is sharply distinguished from
cesophagus and duodenum by the strongly developed
transverse musculature at its proximal and distal ends.
The transverse muscle layer is less strongly and the longi-
tudinal layer more strongly developed than in-~ the
esophagus. At its pyloric end the transverse muscle
layer becomes much thicker and forms the prominent
sphincter pylori, a valve which projects into the cavity
of the duodenum. There is also a very marked differentia-
tion of the mucosa. In the esophagus this consists of a
simple columnar epithelium with goblet cells. In the
stomach the goblet cells disappear and the epithelium is
evaginated to form a closely-set series of gastric glands
over the whole internal surface. Each gland is a tubule,
the internal portion of which is straight and the deeper
portion convoluted. The straight or conducting portion
has a wall consisting of columnar cells with a cement
substance between them, and the lumen is relatively wide.
The deeper or secreting portion has walls made up of large
cubical clear cells, whilst the lumen is narrow. The sub-
mucosa consists of loose areolar tissue containing blood
vessels. The stomach les along the dorsal wall of the
body cavity, and the pylorus is situated at the posterior
end of the kidney.
The Duodenum lies along the posterior wall of the
body cavity towards the eyeless side of the body. Its
proximal end is slightly folded over the distal end of the
stomach. Its wall (and that of the succeeding regions of
the alimentary canal) is thin and consists of an outer longi-
tudinal and an inner transverse layer of unstriated muscle
R
210 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
fibres, of a sub-mucosa lying internal to these, and of a |
mucosa which is a simple columnar or cubical epithelium
containing goblet cells. Four pyloric ceca (Ce. fig. 21)
are present. Day (“ British Fishes,” vol. II., p. 26) states
that only two are present, and Kyle apparently also agrees
with this. When the intestine is distended with food
these ceca may be obscured, but their presence may
always be determined, and in the young fish (of 2 to 4
inches long) they are usually particularly noticeable. One
is present on the dorsal and proximal extremity of the
duodenum, two on the ventral and proximal extremity,
and one on the mid-ventral line about an inch distant (in
large fishes) from the pylorus. This last cecum may be
the largest of the four. They have a wide lumen freely
communicating with that of the duodenum; their wall is
very similar in structure except that the muscle: layers
may not be so distinct. |
The Pyloric Ceca are only seen in Teleostomatous
fishes. The number present is very variable, none being
found in the Sole and 191 having been counted in Scomber.
There has been much discussion as to their morphology
and function. At one time they were regarded as the
homologues of the pancreas—an organ which was then
supposed to be absent in Teleostomi. They Lave been
regarded as absorptive organs and as accessory digestive
glands. Mordecai from observations on Clupea sapidissima
supposed that they served to store up reserve food material.
In the fishes ascending rivers to spawn, when presumably
no food was being taken, the ceca were found distended
with a brownish mucus-like substance which was absent
at other times in the year. Edinger supposed them to
exercise an absorptive function. Wiedersheim also held
this opinion, and correlated their presence with the
absence of a spiral valve (a device for increasing the
SEA-FISHERIES LABORATORY. PAE
absorptive surface of the intestine). Many investigations
have been made on their power of secreting enzymes, and
the results obtained are confusing. Macallum* investi-
gated the structures in Aczpenser, taking particular care
to avoid the entrance of enzymes from the alimentary
canal and pancreas, and found no certain evidence of a
digestive action of their secretion on starch or proteid.
Bonduoyt obtained the opposite results, finding the secre-
tion of the ceca in many Teleosts to behave like trypsin
and to act strongly on starch and proteid. Macallum sup-
poses that they represent the remains of a former series
of digestive diverticula of the alimentary canal. These
became restricted in most vertebrata to certain regions
forming the digestive glands of the canal, but a variable
number, however, persisted in Teleostomi as the pyloric
ceca.
The remaining portion of the intestine hes cn the
ocular side of the body cavity. The duodenum passes
into a tract of intestine which lies along the ventral and
anterior walls of the body cavity to the left of the rectum.
This is thrown into two S-shaped loops which terminate in
the rectum. Near the anus the muscle layer becomes
thicker, and the terminal portion of the rectum is also
connected to the adjacent body wall by strands of connec-
tive tissue.
The Mesenteries are difficult to study on account of
the convolutions of the intestine. They are best examined
in a specimen. well hardened with spirit. Two mesen-
teric sheets appear to .be present, though these may pos-
sibly represent a single structure. One takes crigin from
the dorsal and posterior walls of the body cavity in the
* Jour. Anat. and Phys., vol. xx., pp. 604-636, 1886.
+ Arch. Zool, Exper., vii., pp. 419-460, 1899.
P12, TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
middle lines of the latter, and suspends the stomach and
the greater portion of the intestine, but not the duodenum.
It is curious that the anterior two-thirds of the stomach
are attached to this mesenteric sheet along the mid-dorsal
line, but towards the latter third the attachment is on the
right side, as if the stomach had been longitudinally
rotated from left to right. This mesentery is of course a
double sheet of membrane which encloses the urocyst and
ureter. A second, apparently distinct mesentery takes
origin over the internal surface of the liver, and is
attached to the duodenum and to the greater portion of
the succeeding intestine. The latter is therefore attached
to other parts by means of two mesenteric sheets. The
second mesentery described above covers over the spleen
and bile duct.
The Liver (figs. 20 and 21) is asymmetrical. It con-
sists of two lobes connected by an anterior isthmus of
hepatic tissue. The larger of these lobes forms a flat cake
lying on the eyeless side of the body cavity, and the
smaller lies in the anterior and dorsal corner of the ocular
side, its anterior surface being in contact with the pos-
terior wall of the pericardium (Per. fig. 20). The organ
is suspended to the body cavity wall by the two hepatic
veins (l’. hep. fig. 21) which penetrate the posterior wall
of the pericardium, and by a fibrous sheet passing be-
tween these and attaching the pericardial septum to the
anterior surface of the liver. This anterior surface, as
well as the lateral, is smooth, but the internal surface on
the other hand is thrown into lobules (fig. 21) by deep
furrows in which the factors of the hepatic portal system
run, and along which they can be traced for considerable
distances.
The Gall Bladder (figs. 20 and 21) lies wedged in
between the right hepatic lobe, the right surface of the
SEA-FISHERIES LABORATORY. 918
stomach and the right and dorsal surface of the spleen.
It is a large thin-walled sac about one inch in diameter
in large plaice. It is not imbedded in the liver in any
-way, and is attached to the latter organ by means of the
bile duct only. Its posterior wall is thickened by a little
nodular swelling. Its efferent duct leaves the anterior
and ventral surface, turns back and runs on the internal
surface of the right hepatic lobe partially imbedded in the
tissue of the latter. Three groups of hepatic ducts enter
it: one of these is situated near the proximal end of the
duct, the other two are placed about midway on its course
and enter it from opposite sides. Hach is a group of three
or four ducts. The cystic duct is the portion of the whole
duct between the gall bladder and the opening of the first
hepatic duct, the remaining portion is the common bile
duct. The walls of the bile duct are slightly iridescent,
the distal extremity is thick and swollen, but encloses a
very narrow lumen. It enters the duodenum between the
paired pyloric ceca. Its opening into the duodenum is
extremely small, and is very difficult to observe from the
interior of the latter. The bile is a transparent slightly
greenish fluid. The liver in the plaice, as in all other
vertebrates, has a double blood supply, receiving blood
from the veins of the intestine by the hepatic portal
channels and from the dorsal aorta via the cceliaco-mesen-
teric artery by the very small hepatic artery (A. hep. fig.
22). Of these sources the hepatic portal system of veins
is by far the most important, and the system of intra-
hepatic vessels containing venous blood is exceedingly
striking in sections of the organ. The liver is essentially
a tubular gland, but the hepatic tissue is disposed in
strings of cells in which as a rule the lumen or bile capil-
lary is only apparent from the radiate arrangement of the
hepatic cells in transverse section of the strings. Within
914 ‘'PRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
the liver pancreatic tissue surrounding the bloodvessels
is also present.
The Pancreas is apparently absent in Pleuronectes,
but is really present in a diffuse form. It will be noted
that a perivascular tissue is stated to occur round
all the visceral blood vessels and particularly round the
factors of the hepatic portal system. This tissue appears
on naked eye examination as a band on either side of the
vessel equal to or greater than the diameter of the latter.
It lies of course within the thickness of the mesentery in
which the blood vessels travel. It is particularly abun-
dant round the vessels in the vicinity of the pyloric ceca,
where it forms nodular masses which are also associated
with fatty tissue. This diffuse perivascular tissue is the
pancreas, which nowhere has the massive’ form charac-
teristic of Elasmobranch fishes. It recalls the extended
form of organ characteristic of Mammalia, except that
here the gland acini have a constant association with the
blood vessels, forming an investment round the latter.
No proper pancreatic blood vessels are accordingly present.
Text-fig. 1, B. is a section through a small portion of the
mesentery including two branches of the cceliaco-mesen-
teric artery and a small factor of the hepatic portal system.
Tt will be seen that the mesentery is greatly thickened
round the blood vessels, and this thickening is really due
to a mass of gland acini. No attempt is made in the
figure to represent the structure of these acini, but their
radiate grouping round the portal vein is indicated. Llse-
where in this section they had no definite arrangement.
Nodular masses of pancreatic tissue are also present round
the paired pyloric ceca, and from these some small ducts
enter the ceca. Probably a number of such efferent ducts
are present, but we have not determined this exactly. The
gland acini have the structure characteristic of the
SEA-FISHERIES LABORATORY. 215
Fic. 2.
Longitudinal.
Muscles.
\\
; a Le Dorsal aorta
: A cad
i Rose neo
a by Pacha wits Peoize
Nephrostome- Pye. iy \ ¢A.\.-+--tNephrostome
cat Omen S\ = aan : f
SATS BF i a Pronephric
as mee FT NT
f Sag AT { \ chamber
Segmental es Y ces
pact j Wane ots Segmental
aes rd : s 4 | duct
) has 3 Wee oea M
ATS
A ae “~iOesophagus
Fic 1.A
Hepatic tisSue_........-. y
A % yh
NEESA ANS
%° AON :\
Vy 3758 EA
UN Ags \ Mesenteric
xv Arteries
a
Pancreas
Portal wn
=- Muscle layer \
‘Fic. 1. A. Section of liver, showing pancreas round a vein, x 225.
Fic. 1. B. Section of a part of the mesentery, x 22.
Fig. 2. Part of a transverse section of a 12 days’ old larva.
Fic. 3, Transverse section of ovarian wall, x 26.
216 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
pancreas. A lumen is not generally apparent, but the
presence of such is generally associated with a particular
phase of the activity of the gland which doubtless did not
coincide with the fixation of our material of the organ.
They are small and in a single transverse section are
composed of few polygonal cells.
Not only does the pancreatic tissue form a peri-
vascular investment in the vessels in the body cavity, but
it extends along the portal veins into the interior of the
liver. Text-fig. 1, A. represents a section of a part of the
latter organ, and shews a small portal vein cut in trans-
verse section with two veinules opening out from it and
passing between the hepatic cells. A single layer of
pancreatic gland acini forms an investment for the vessel,
and the whole les within a space in the hepatic tissue
which is probably natural. The acini are elongated per-
pendicularly to the surface of the vessel, and the whole is
surrounded by a fibrous sheath which sends in partitions
between the acini, becoming continuous with the fibrous
wall of the vein. Here also a lumen is generally wanting,
or is only with difhculty apparent in the acini.
In Acipenser, Ama and Lepidosteus Macallum* has
described very similar relations for the pancreas, and the
description of the organ given by Gullandt for Salmo
answers in all essential respects to that stated above.
Macallum#{ has described the pancreas in Amzurus as being
imbedded in the liver round the interlobular veins. The
diffuse condition of the pancreas seems to be characteristic
of most Teleostomatous fishes hitherto investigated, and is
most probably quite general.
* Loc. cit.
+ Life history of the Salmon; Rep. to the Fishery Board of Scotland, 1898,
t Proc. Canadian Institute, N.S. vol. 1., No. 3, pp. 387-417, 1884.
SEA-FISHERIES LABORATORY. 917
3.—TuHE DucriEess GLANDS.
It will be most convenient to consider here a group of
glands (the thyroid, thymus, spleen and _ suprarenal
bodies), though these structures have a widely different
morphological significance and have most probably very
different functions. They agree in being glandular bodies
devoid of efferent ducts, and acting in modifying the com-
position of the blood either by adding to it some sub-
stance (internal secretion), or by withdrawing some por-
tion of its constituents. The lymphatic portion of the
kidney is also supposed to function in some such way, but
this structure will be most conveniently considered
together with the renal organs.
The Thyroid in Plewronectes is not a compact gland,
and is relatively very small in mass. It consists of a
number of separate alveoli situated along the course of
the ventral aorta. It is difficult to find by dissection in
the full-grown specimen, and must be identified in a fish
sufficiently small to section as a whole, or by microscopic
examination of the tissues surrounding the vessel in
question. ‘The separate alveoli of which it is composed are
not bound together in any way, but le loosely in the
connective and fatty tissue in which the ventral aorta is
imbedded. They are most abundant in the immediate
neighbourhood of the origin of the Ist and 2nd efferent
branchial vessels, and lie mostly ventral to the aorta, but
may be found lateral, and even dorsal, to it. In a trans-
verse section through the region indicated in a small fish
15 to 2 inches long there may be about a dozen alveoli
present in a single section. Round the ventral aorta
between the places of origin of the branches referred to
and between the 3rd and 4th vessels few alveoli are pre-
sent, though one or two may be found here and there.
2t8 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
Each alveolus is a small rounded or oval closed sac; the
largest is about 0°‘07/mm. in diameter, but they vary in
diameter within wide limits. The wall is made up of a
single layer of columnar cells outside which a delicate
sheath may often be distinguished. Hach alveolus is filled
with the colloidal substance characteristic of the thyroid,
which usually stains shghtly with eosin. It may be con-
tracted away from the wall in section, but this appearance
is most probably artificial and in life the alveolus is un-
doubtedly filled.
The thyroid originates in Salmo* (and probably in all
Teleosts) as a median evagination of the ventral pharyn-
geal epithelium which has no connection with the gill
clefts. This evagination forms a little vesicle, the cavity
of which at first communicates with that of the pharynx
by a tubular stalk. Later on the stalk becomes solid and
the vesicle separates entirely from the pharyngeal wall.
It then shifts backwards towards the heart, and its wall
begins to form hollow buds, which later on separate and
become closed. These persist as the definitive thyroid
alveoli. Paired rudiments do not, as in higher verte-
brates, contribute to the formation of the adult gland.
The Thymus (7Z'Am. fig. 21) lies internal and shghtly
posterior to the posterior and dorsal corner of the oper-
culum. On dissecting away the skin in this region a sheet
of muscle fibres is seen originating at the cranial ridge
connecting the 4th and 5th tuberosities (70. 4; Tb. 95)
and inserted into the dorsal border of the operculum.
When this is dissected off the thymus is seen lying under-
neath and immediately in front of the supra-clavicle
(S.Cl. fig. 8), between this and a slip of muscle which
originates in the pterotic at the base of the 4th
** Maurer, Schilddriise u. Thymus der Teleostier. Morph. Jahrb., Bd. xi.,
pp. 1380-175, 1885.
SEA-FISHERIES LABORATORY. 919
tuberosity and is inserted into the upper end of the
clavicle. It is a flattened glandular mass occasionally
eovered with black pigment spots. In a fish of about 20
inches in total length it is about lcm. in length, half
that in breadth, and about 2mm. in thickness. It lies
with one edge uppermost. Its artery appears to be a branch
of the subclavian, its vein opens into the superior jugular.
It hes immediately external to the roots of the vagus, and
this association of the gland and nerve appears to be a
constant one in fish of all sizes from the stage at which
the structure is definitely formed. Its histological struc:
ture is that generally characteristic of the thymus gland
of vertebrata. It consists of small rounded cells closely
packed together in a narrow-meshed reticulum of connec-
tive tissue. The cells have large nuclei and attenuated
cell bodies. The whole gland is surrounded by a loose
capsule of connective tissue which is continuous with the
internal reticulum. ‘There is no well marked differentia-
tion into cortical and medullary regions except that in
adult specimens a narrow peripheral zone stains more
intensely than the rest of the gland. Fatty tissue is little
developed, and concentric corpuscles are apparently absent.
The thymus in Salmo* (and probably in all Teleostean
Fishes) develops, like the organ in Elasmobranchs, from
proliferations of the epithelium clothing the dorsal ex-
tremities of all the gill clefts. These originally separate
thymus buds fuse together while still in connection with
the gill clefts, and for a time their cells can be traced
continuously into the epithelium of the cleft. The whole
organ then separates from its parent tissue and undergoes
a backward shifting into its adult position.
_ The Spleen (Sp/. fig. 21) lies on the internal surface
of the left lobe of the liver, usually wedged in between
* Maurer, Loe. cit.
92.0 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
the pylorus, the lower surface of the stomach and the
distended gall bladder. The bile duct (Bd.) lies imme-
diately underneath it. It is covered over or attached by
the mesenteric sheet connecting the duodenum and suc-
ceeding portion of the intestine to the liver. A prominent
branch of the cceliaco-mesenteric artery (A.sp. fig. 22)
supplies it with blood. It is oval in shape, and in a large
fish is about 1 to 2cm. in longest diameter. It is black in
colour, and is very soft and easily torn. Its structure is
the characteristic splenic one. There is a strong fibrous
investment which is continuous with strong trabecule
passing inwards and dividing the whole gland up into
lobules... The reticular formation within the lobules is
filled with the characteristic splenic pulp, and in the
centre of each Icbule is a mass of densely oggregated
lymphoid cells round which the texture of the pulp is
looser. A prominent vessel passes to each of these
nodules. ‘This structure is best seen in the organ of quite
small fish, as in larger specimens it is much more obscure,
and granular masses of black pigment are abundantly
present. These pigment masses are composed of rounded
granules of variable diameter.
The Supra-renal Bodies are situated on the morpho-
logical dorsal (spinal) surface of the kidney on the perpen-
dicular surface which is apposed to the Ist haemal spine
at about 4 of the length of this surface from the extreme
tip of the kidney. To display them the kidney must be
removed from the body, and since this is difficult on
account of the soft pulpy nature of the organ in the fresh
condition, the dissection is most conveniently carried out —
on preserved specimens. ‘he structures in question are
then seen as two oval or rounded bodies lying close
together, one on each side of the middle line to right and
left of the common genital artery (A.gen.) at the point
SEA-FISHERIES LABORATORY. poe
where the latter vessel leaves the kidney. They are
yellow or pink in colour, and contrast strongly with the
pigmented kidney. In a specimen of about 22 inches in
total body length, the largest measured 5°5mm. in longest
diameter. They he in little cavities in the kidney tissue,
but project slightly above the surface of the latter, in the
capsule of which they are enclosed. Their blood supply
is from a twig of the common genital artery, and their
minute structure is somewhat similar to that of a
lymphatic gland. The capsule is continuous with a system
of fibrous trabecule traversing the whole organ. These
trabeculee form the coarser bars of a reticulum the meshes
of which are crowded with small cells which may be
described as lymphoid in appearance. According to
Vincent they are secreting glands affecting the composi-
tion of the blood by furnishing an internal secretion.
Until comparatively recent times it was supposed that
the suprarenal bodies were absent in Teleostean fishes.T
It has, however, been shewn by Vincent* that they are
probably universally present. As is well known, the
suprarenals of mammalia consist of two morphologically
distinct portions—the cortex and medulla. The latter has
been stated to have been derived from certain of the sym-
pathetic ganglia, and concerning the former an interesting
suggestion has been made by Weldon and Grosglik. It is
certain, however, that the most important relations of the
suprarenal bodies are with the vascular, not the nervous
system.
4.—Tur Renat OrGanNSs.
The Kidney (figs. 20 and 21) lies along the whole
dorsal, and part of the posterior wall of the body cavity,
+ Cp. Weldon—Head Kidney in Bdellostoma—Studies Morph. Lab.
Cambridge, vol. ii., pt. 1, 1884.
* Contributions to Anatomy and Histology of the Suprarenal Capsules.
Trans. Zool. Soc., London, vol. xiv., pp. 41-84, 1896-8.
2D, TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
from the 2nd to the 14th vertebrae. Its greater portion is
covered laterally by the transverse processes and ribs of
those vertebre. Its ventral surface forms the roof of the
body cavity. Posteriorly it increases very much in thick-
ness dorso-ventrally and occupies the angle formed by the
vertebral column and the nearly perpendicular 1st haemal
spine and axonost, and laterally by the 7th to 10th ribs.
It is for the greater portion of its length a single un-
divided mass, but anteriorly is produced into two tapering
and diverging horns—the head portions of the kidney,
which lie laterally and dorsally from the esophagus. The
right unpaired cardinal vein runs along the middle line as
far as the thickened portion, and is visible on its ventral
surface. Dorsally the aorta lies in a groove in the middle
line, and this with the cardinal vein separates the
uriniferous tubular tissue into two paired masses. Only
in the thickened posterior portion of the kidney is this
tubular tissue continuous across its whole breadth.
At the dorsal posterior corner of the kidney the caudal
vein enters as a single vessel which almost immediately |
divides into paired portions. © Apparently it does not
become continuous with the cardinal vein, but breaks up
round the uriniferous tubules, though there are doubtless
anastomoses between the two vessels. The extreme
ventral portion of the kidney is produced downwards into
paired tips, and into these the paired genital veins (V.gen.
fig. 21) enter. Along the dorsal surface of the organ other
paired venous trunks (parietal veins) also enter. The
most anterior of these vessels is shewn in fig. 22 entering
the extreme anterior tip of the head portion of the kidney. -
The caudal, genital and parietal veins, with the renal
arteries are the afferent vessels of the kidney. The paired
posterior cardinal veins are its efferent vessels.
The Ureter (Uret. fig. 21) leaves the ventral and pos-
SEA-FISHERIES LABORATORY. 22.3
terior surface of the kidney between the paired. terminal
processes into which the genital veins open. It is a single -
-tube which immediately on entering the kidney divides
to form the paired segmental (or Wolffian) ducts which
traverse the entire length of the organ. ‘The ureter
rapidly expands into the urocyst (urinary bladder), a large
thin walled sac lying between the ovaries (or testes) in
front of and rather to one side of axonost 1. Its most
expanded portion is near the rectum. Its cavity then
rapidly diminishes, and the efferent ureter is a tube with
an extremely contracted lumen. It passes to the right
side and runs forwards in the dense connective tissue of
the body wall, surrounding and posterior to the anus. It
then curves laterally at a sharp angle and opens externally
on to the surface through the urinary papilla. The latter
(Ur. pp.) 1s an unpaired prominent projection of the body
wall to the right side and immediately posterior to the anus.
Detailed observations of the development of the
Teleostean urocyst are few, but it seems most probable
that it is of hypoblastic origin, and that its cavity, unlike
that of the segmental duct, which is ccelomic, is really a
cloacal portion of the hind gut. McIntosh and Prince*
give a description of the early condition of the vesicle in
Molva, though its origin or latter fate is not described.
In the youngest plaice (one week after hatching) of which
we have made serial sections the united segmental ducts
appear to open into the hind gut, which does not yet open
to the exterior. In plaice a fortnight old the hind gut
opens externally, and the urocyst ceases to have any connec-
tion with its cavity, but opens independently in the middle
ventral line of the body immediately behind the anus.
The secretory tissues of the kidney are the uriniferous
* Development and Life Histories of Teleostean Fishes. Trans. Roy.
Soc., Edinburgh, vol. xxxv., pt. 8, No. 19.
294 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
tubules, which are somewhat sparsely distributed in the
‘anterior part of the organ, but are very abundant in the
thickened posterior portion. They are greatly convoluted
tubules of varying diameter opening into the ureters. It
is somewhat remarkable that Malpighian bodies are very
difficult to find, and indeed seem to be absent, in some
parts at least, of the kidney. This condition is connected
with the vascular arrangements of the organ. By far the
greater portion of the blood entering it is venous, and the
arterial supply is very scanty. Two, or at most three, very
small vessels originating directly in the dorsal aorta enter
at the dorsal surface, and the common genital artery
(A. gen., fig. 22) gives off several very fine arterial twigs
which ramify in the posterior portion. The whole arterial
blood supply is very small compared with the amount of
venous blood entering by the renal portal veins.
The lymphoid tissue which is so frequently met with
in the kidneys of fishes is most abundant in the middle
and anterior regions of the plaice kidney. It consists of
very small cells, supported by reticular connective tissue,
and filling up the interspaces between the blood vessels
and the uriniferous tubules. Groups of pigment granules
are scattered throughout this lymphoid tissue and give the
organ its black appearance. ‘They are small rounded
granules of variable diameter, and of a greenish-black
colour. They he freely among the lymphoid cells.
The Pronephros and Head Kidney (Text-fig. 2).—
The kidney in Pleuronectes is a mesonephros, and its
paired ducts are segmental or archinephric ducts. The
most common mode of origin of these structures in
Teleosts is by a longitudinal evagination of somatopleure
forming a groove which afterwards closes by constriction
of its lips, giving rise to a tube. McIntosh and Prince
state, however (loc. cit.), that in Gadoids and Pleuro-
SEA-FISHERIES LABORATORY. 225
nectids the segmental ducts originate as solid rods, which
afterwards acquire a lumen by the radiate arrangement of
their cells. This condition, however, is most probably a
secondary one, and the mode of development as a longi-
tudinal groove seems most primitive. The cavity of the
paired ducts of the adult kidney and that of the tubules is
accordingly ccelomic in its nature. During larval life
these ducts are the efferent channels of the pronephros—
the larval excretory organ.
The Pronephros is probably formed before the larva
hatches from the egg. Text-fig. 2 represents the condi-
tion of the organ in a plaice 12 days old. It is part of a
_ transverse section through the anterior part of the trunk
immediately behind the gill-bearing region. Here the
segmental duct makes two or three convolutions and opens
by a non-ciliated nephrostome into a small chamber.
The right and left pronephric chambers le side by side,
separated by athin septum. The dorsal aorta lies between
them in the dorsal thickened part of the septum. A
vascular tuft, the glomus, projects from the lateral wall
of the aorta into each pronephric chamber opposite the
nephrostome. The whole organ lies between the noto-
chord and the csophagus. It has no connection, at
least in the stage studied, with the body cavity, but
there can be little doubt that the pronephric chamber is
simply an enclosed portion of the general celom. The
whole organ is essentially similar to the pronephros of
Lepidosteus as described by Balfour and Parker, except
that in the latter form the pronephric chamber still com-
municates with the body cavity by a richly ciliated funnel.
The glomus is really a tuft of capillaries in communica-
tion with the aorta. The resemblance of the whole struc-
ture to a Malpighian body of the kidney with its contained
glomerulus will be noted.
S
2926 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
The pronephros degenerates at a variable age. We
have seen it in a plaice of about 4 inch in length, that is
at an age when the metamorphosis of the larva is com-
plete and the adult asymmetry thoroughly established. -
The Head Kidney.—In a continuous series of sections
from a plaice of about one inch long passing through the
whole length of the kidney, the latter organ can be'seen
to be divided into three ill-defined parts. The posterior
or thickened portion of the .kidney is crowded with
uriniferous tubules cut in various planes, Malpighian
corpuscles can be seen, though these are very few, and the
lymphatic tissue is (relatively) not abundant. Anterior to
this, and occupying the thinnest middle portion of the
kidney, is a region where the segmental duct, shghtly
expanded, alone persists, but no uriiferous tubules are
present in the sections. This is the intermediate portion
of the kidney. Anterior to this, and beginning at the
plane of transition of stomach into esophagus, is a region
where the segmental duct becomes thrown into convolu-
tions. Here, too, the kidney divides into the two anterior
horns which lie on either side of the esophagus. This is
the head kidney, and it contains lymphatic tissue. This
tissue is present through all the length of the kidney, but
is more abundant in the anterior portion, and here it
is aggregated into nodules with well-marked blood chan-
nels between: that is, it has characters intermediate be-
tween a true lymphatic and haemolymph gland.
In the oldest specimens investigated this swollen
anterior portion of the kidney has no traces of uriniferous
tubules or segmental duct. It consists only of a modified
form of lymphatic tissue with large blood vessels. In it
are nests of black pigment in the form of irregular
granules, and its wall also is deeply pigmented.
These anterior swollen portions. are the degenerate
SEA-FISHERIES LABORATORY. 2.2.7.
remains of the larval pronephros. This identification is
confirmed by a study of various early stages. In the
youngest forms examined (symmetrical larve one to two
weeks hatched), the mesonephric tubules are absent, or are
only just forming, while the segmental duct extends
anteriorly as a straight line which becomes convoluted in
‘its anterior extremity forming the pronephros. In a later
stage (asymmetrical fish 3/5th inch long) the three regions
of the kidney described above are well marked, the latter
portion presenting all the characters of a mesonephros,
while the nephrostomes and glomi of the pronephros are
still recognisable, though much reduced. In an asym-
metrical form about one inch in length, the intermediate
lymphatic portion is relatively shorter, the mesonephric
portion with its Malpighian corpuscles has extended fur-
ther forward, the pronephric convolutions of the seg-
mental duct are still present, but glomi, pronephric
chambers and nephrostomes have disappeared and lym-
phatic tissue and blood spaces are largely developed.
Finally in the oldest adult specimens examined the head
kidney contains only lymphatic tissue.
The pronephros probably degenerates in all Teleostean
fishes with the exception of one or two specialised forms.
Organs formerly supposed to represent a persisting func-
tional pronephros such as are present in Lophius have
been shewn to be anterior extensions of the mesonephros,
and others such as those present in Anguilla and Hsow are
lymphatic organs with degenerate remains of the
pronephric convolutions. Only in Frerasfer, and perhaps
Zoarces, is the evidence conclusive that a functional
pronephros exists in adult life. In Dactylopterus Calder-
wood* has described an organ which he regards as a func-
tional pronephros, but in this case it is still probable that
* Jour, Mar. Biol. Assoc., vol. ii. (N. S.), pp. 43-46, 1891-2,
2998 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
we have to deal with an anterior extension of the mesone-
phros, and conclusive proof of Calderwood’s hypothesis
would only be afforded by tracing the embryonic
pronephros into the structure so termed in the adult.
Concerning the representative of the lymphatic head
kidney of Teleostean fishes in higher vertebrata, Weldont
put forward the suggestion that they exist in the supra-
renal bodies. But he thought that the latter bodies were
very generally absent among Teleosts, whereas it is now
known that they are present in all forms sufficiently in-
vestigated. It is only the medullary portions which are
present, however, and Grosglkt has suggested that the
homologues of the cortical parts of the suprarenal bodies
of higher vertebrata are present in Teleosts as the
lymphatic portions of the head kidney. According to
Kmery, this lymphatic tissue is to be derived from the
peritoneal epithelium. It is a formative blastema which
remains 2m statu quo on the reduction of the pronephros.
D.—THE BLOOD VASCULAR SYSTEM.
The heart in Plewronectes, as in all fishes, is a respira-
tory one, and consists of a single auricle and ventricle.
The de-oxygenated blood which it contains is propelled
into the gills, and after passing through the respiratory
capillary network in the branchial lamelle reaches a
great loop-shaped vessel—the circulus cephalicus—lying
beneath the base of the skull. From the circulus
cephalicus, which contains oxygenated blood, the carotid
arteries pass forwards to supply the brain and head,
the cceliaco-mesenteric artery enters the body : cavity
and supplies the viscera, while the rest of the body
is suppled by the dorsal aorta. De-oxygenated blood,
+ Loe, cit: t Anat, Anz., Jahrg., viii., pp. 605-611, 1885,
SEA-FISHERIES LABORATORY. 229
after traversing the systemic capillaries, returns
through three main channels. The blood from the
head returns directly to the sinus venosus by the
jugular veins, but two portal circulations are interposed
in the course of the blood returning from the viscera and
_ the body. The caudal vein, the genital veins and other
smaller vessels convey blood returning from the great
muscles of the trunk and from the reproductive organs to
the kidneys, where these afferent veins break up into a
network of capillaries, which are in close association with
the renal tubules. From the kidney the blood 1eaches
the heart again via the two ductis Cuvieri, or precaval
veins; the blood from the stomach, intestine and spleen,
containing the absorbed products of digestion, 1s conveyed
to the liver by several afferent vessels known as the hepatic
portal veins, and after traversing the hepatic capillaries
enters the sinus venosus by the hepatic veins.
The Pericardium and Heart.— The pericardial cavity
(Per. fig. 20) is displayed by dissecting away the pectoral
girdles with their muscle masses, which cover it laterally
and in front; behind, it is bounded by a strong fibrous
septum which separates it from the body cavity. Its walls
contain black pigment. The heart, which nearly fills its
cavity, 1s suspended by the hepatic veins traversing its
posterior wall, by the ductiis Cuvieri above, and by the
bulbus arteriosus in front. I+ lies in a curved position, so
that the sinus and auricle are nearly vertical, the ventricle
oblique and the bulbus nearly horizontal.
The Cuvierian Ducts or precaval veins (V. pe. fig. 22)
are wide thin-walled vessels passing slightly obliquely
over the lateral surfaces of the cesophagus. Their union
beneath the latter forms the sinus venosus (Sin. V. figs.
21 and 22). Sinus and precaval veins together form a
horse-shoe shaped chamber surrounding the cesophagus
230 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
on its lateral and ventral surfaces. In the middle of its
ventral wall is the sinu-auricular orifice through which its
cavity communicates with that of the auricle. This open-
ing is guarded by a rather weak valve consisting of two
membranous flaps, anterior and posterior in position,
which hang down slightly into the cavity of the auricle.
The large vessels opening into the sinus are the paired
precaval veins into which open the paired posterior car-
dinal veins (V. card.), the paired hepatic veins and the
unpaired inferior jugular vein.
The Auricle (Awr.) lies dorsal and anterior to the
ventricle which it partly enfolds. Its external surface is
lobulated, the postero-dorsal portion being produced into
two notable lobes. Its walls are thin, but are strength-
ened internally, especially on their dorsal and ventral por-
tions, by interlacing muscle bands—the musculi pectinati.
A deep auriculo-ventricular groove separates it from the
ventricle. Its cavity communicates with that of the latter
by the auriculo-ventricular orifice, which is guarded by
three semi-lunar valves—pocket-shaped membranous flaps,
the cavities of which face the cavity of the ventricle.
Two of these valves are large, and are nearly anterior and
posterior, whilst the third is much smaller, and is situated
laterally.
The Ventricle (Ven.) lies ventral and posterior to the
auricle. Its walls are very thick, and are produced
internally into ridges—the columne carneex, which
largely reduce its cavity. It is separated by a deep con-
striction from the bulbus arteriosus (B.A.), which is a
flask-shaped dilatation of the proximal end of the ventral
aorta. Its cavity communicates with that of the bulbus
by an opening which is guarded by two strong semi-lunar
valves. The wall of the bulbus is composed of fibrous
connective tissue free from muscle fibres. It is very
SEA-FISHERIES LABORATORY. 231
thick, and its internal surface is produced into longi-
tudinal folds.
The Afferent Branchial Vessels.—The ventral aorta
(do. V.) continues forward the bulbus arteriosus. It
runs forward in the middle line of the body beneath the
cesophagus and the ventral extremities of the gill arches.
Its wall is composed of fibrous connective tissue appa-
rently without muscle fibres. Like all the larger blood
vessels in the plaice, it contains black pigment. Three
afferent branchial vessels are given off at nearly equal
intervals on each side. The first of these almost immedi-
ately divides into two vessels of equal calibre (Af. Br. 4;
Af. Br. 3) which supply the 4th and 38rd holobranchs.
Separate vessels (Af. Br. 2; Af. Br. 1) are given off to
the 2nd and Ist holobranchs. The ventral aorta ter-
minates by dividing to form the Ist afferent branchial
vessels. Hach afferent branchial vessel enters the gill at
about one-third of the length of the latter from the ventral
extremity, and immediately divides into two branches
which traverse the whole length of the gill, running on
the concave surface of the gill arch.
The Structure of the Gills. —It will be convenient to
describe here the minute anatomy of the gills before con-
sidering their vascular arrangements. In the Plaice, as
in most T'eleostean fishes, there are four functional gills.
Hach gill is a holobranch, and consists of two separate
series of gill filaments borne on the same branchial arch,
each of which represents the demibranch or single series
of filaments found on the one side of a gill pouch of an
‘Klasmobranch fish. In the Teleostomi the septum which
in the Klasmobranch separates the two adjacent demi-
branchs has disappeared, with the result that the two series
of filaments borne by the same arch have become closely
opposed.
232 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
Kach branchial arch (Text-fig. 4, A.) consists of several
pieces, and is for the most part a densely calcified tube,
the ends of which are cartilaginous. The interior of the
tube is strengthened by bony trabecule. The gill fila-
ments are borne on the posterior and convex borders of
the gill arches. On first inspection it may appear that
there is only one series, but closer study shews that there
are really two. ‘This is particularly noticeable in the
anterior gills, where the two series of filaments are of
unequal length, so that all the anterior (or external) are
longer than the posterior or internal ones. The bases of
all the filaments borne on one branchial arch are fused
together, but the greater portions of them are free from
each other. In section (Text-fig. 4, B.) each filament is an
isosceles triangle. They are so disposed that the apices
of the triangles are directed towards each other and those
of the one series alternate with those of the other.
Obviously this arrangement secures the greatest economy
of space consistent with the size of the filaments.
Text-figs. 4 are a diagrammatic representation of
the structure of the gill filaments. Fig. A. is a
diagrammatic transverse section of a gill arch, and shews
two filaments belonging to adjacent demibranchs. Hach
filament is supported by a cartilaginous rod—the gill ray
which runs down in its axis. These gill rays are super-
ficially calcified ; their proximal ends are swollen and are
all fused together, but the connecting portions are not
calcified. The skeleton of a demibranch is therefore a
comb-like structure. The rays of the adjacent demi-
branchs are placed alternately, so that the knob-like calei-
fied proximal end of one ray is placed opposite the car-
tilaginous connecting portion of the iwo opposed ones.
Dense ligamentous bands connect the fused heads of the
gill rays with the branchial arch and with each other.
SEA-FISHERIES LABORATORY. 9338
Trext-Fie. 4. Structure of the Gills:
— Gil! Raker. eS
_R.Post-trematicus dorsalis 1X
~ _~Branchial arch.
Zz ?
Pa
a
___-Efferent pranchia! vessel.
_-R.Pre-trematicus primus X.
-
__--R Post-trématicus ventralis IX.
p< ie Afferent branchial vessel.
nar eee- Base of gill ray.
__- Filamentar muscie.
~>s- Afferent-7
filamentar vessel |
oS
2
;
' Capiliary plexus.
Gee er oe eee -Gill ray.
Efferent filamentar vessel:
\
< fi rateete be
Int. : ;
Gill ray. .
ee an a Poe Oe a
i Capillary plexus. —
»
ss
seaed
Vascular lamella.
or
| Dad
A. Diagrammatic transverse section through Branchial arch I. B. Trans-
verse section of a double filament, showing the surfaces of two lamelle.
C. Longitudinal section of a single filament in a plane at right angles to A.
934 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
These structures, the convex surface of the gill arch, the
proximal ends of the gill rays and the ligaments, form a
tunnel through which pass the efferent branchial vessels
and certain of the nerves of the gill. A very definite
httle muscle takes origin in the cartilaginous connecting
portion of every two gill rays, passes obliquely downwards
into the tissues of the opposite gill filament, and is in-
serted into the upper portion of its gill ray. This is part
of an extremely pretty mechanical arrangement. It has
been stated that each half filament is in section an isosceles
triangle, and that the two series dove-tail into each other
on account of their alternate arrangement. Obviously the
contraction of the little muscles described above must have
the effect of approximating the two series and obliterating
the spaces between all the separate filaments; conversely
the relaxation of the muscles and the elastic recoil of the
gill rays must separate all the filaments attached to a
single arch, leaving a space between each two, and this is
effected without any alteration in the total length of the
gill. It seems extremely probable, though we have no
experimental evidence on the point, that these movements
do actually take place in life, and that they aid in the
movement through the gill of the respiratory water.
- Text-fig. 4, C. is a longitudinal section through a gill
filament in a plane at right-angles with that of 4, A. It
shews that each filament consists of a flattened axis which
bears on either side a close-set series of lamelle. The
axis is strengthened by dense connective tissue, and con-
tains the gill ray and the filamentar blood vessels. Text-
fig. 4, B. is a transverse section of a double filament
between the centres of two lamelle. It shews the position
of the axis and the gill ray.
If the branchial blood vessels are injected from the
ventral aorta, a series of vessels become apparent on the
SEA-FISHERIES LABORATORY. 935
internal (with respect to the middle line of the gill arch)
sides of the filaments. These are the afferent filamentar
vessels (4, A. and B.), and they are connected with the
afferent branchial vessels which run in the fused bases of
the filaments outside the tunnel referred to. If, on
the other hand, the system is injected from the dorsal
aorta, a second series of vessels which run down on the
outer surfaces of the filaments becomes visible; these are
the efferent filamentar vessels, and they are vonnected
with the efferent branchial vessels which run in the tunnel
on the convex surface of the arch. At regular intervals
along its course the afferent filamentar vessel gives off an
arterial twig on either side of the axis of the filament
which passes into the respiratory lamellee (4, B).
Text-fig. 4, B. represents a surface view of two
lamelle, the transverse section of the filament passing
through the axis between two such lamelle. In a
fortunate injection of the branchial system it will be seen
that the lamellar branches of the afferent filamentar vessel
on entering the lamelle immediately break up into very
close capillary networks. ‘This capillary network, seen
from the side, is represented by the transverse black lines
connecting the two filamentar vessels in 4, A. Lach
lamella has a wall which at the base is composed of cubical
cells, but which over the flat surfaces is a thin squamous
~ epithelium. Within the space enclosed by this wall is the
capillary network, and no other tissues. According to
Plehn* the blood flows in spaces hollowed out of adjacent
closely-fitting cubical cells. The capillaries have not the
ordinary epithelial wall characteristic of such vessels.
After having traversed this network the blood is received
* Zum feineren Bau der Fischkieme. (Vorl. Mitth.) Zool., Anz, No, 648,
24 Bd., pp. 489-443, 1901.
236 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
by a very short vessel which opens into the efferent
filamentar vessel.
Respiration _is effected by rythmical swallowing
movements of the mouth and co-ordinated liftings of the
opercula. The water swallowed passes from the pharynx
through the gill slits and over the surface of the gill fila-
ments. Probably movements of the latter in the mode
already suggested assist in this circulation of the sea
water. The gaseous interchange between the blood in the
respiratory lamelle and the water takes place through the
extremely thin walls of the latter and the walls of the
capillaries. Only two thin epithelia separate the two
liquids, and through these carbon dioxide passes from the
blood to the sea water, and oxygen from the sea water to
the blood.
_ The respiratory area of the gills can be approximately
calculated. The lengths of the gill filaments vary, and
the greatest number of lamelle counted on any one side
of a filament was 225; probably 150 will represent the
average number to a side of a filament; there are two
series of lamella, of course, on each filament. Therefore
we have :—
| Holobranchs. No. of Filaments.| No. of Lamelle.
|
‘i 83 x 4 99600 |
IL. 78 x 4 93600 |
aie ail 72x 4 86400 | |
locrere “E 58 x 4 69600
Total ... 1164 | 349200 |
SEA-FISHERIES LABORATORY. Daa
Now the area of each lamella can be approximately calcu-
lated, since it is nearly triangular. It is roughly 0°365
square millimetre. But since both the flat surfaces of the |
lamella are in contact with the water, the respiratory sur-
face is double this, and is 0°730 sq. mm. x 349,200 = 254,916 |
sq.mm. That is over { square metre. The total respira-
tory surface of the gills is therefore that of a square, the
length of the side of which is } metre. These calculations
apply to a plaice of about 22 inches long. The area of the
skin of such a fish is approximately 2,340 sq. cm., or
nearly 7 sq. metre. The respiratory surface of the gills is
therefore about equal to the total area of the skin.
The Efferent Branchial Vessels —The blood, after
having passed from the heart and afferent vessels through
the lamellar capillaries, is collected by four trunks on
each side—the efferent branchial vessels. These open
into the epibranchial arteries of each side. Posteriorly
the two epibranchial arteries (A. ep.) unite to form
the dorsal aorta; anteriorly they are connected
together by a short anastomosing vessel (C2. c.).
The loop thus formed is the circulus cephalicus. It is the
reservoir into which the blood, after having undergone
oxygenation in the gills, is poured, and from which it is
distributed over the body. The efferent branchial system
is best injected from the dorsal aorta after tying the
celiaco-mesenteric artery. It can be displayed after
cutting away the greater portion of the operculum of one
side, removing the opercular, sub-opercular and inter-
opercular bones. The remaining dorsal portion of the
operculum is then forced outwards and held in position by
a hook. The gill filaments should be cut away close to
the arches. The vessels themselves are then seen, after
dissecting apart and removing most of the muscles, pass-
ing dorsally from the gill arches, The circulus cephalicus
238 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
and carotid arteries can be dissected by removing the
greater portions of both opercula as indicated above, and ~
then cutting away the gills, having previously divided the
efferent vessels as far away from their attachments to the
epibranchial arteries as possible. The head is then placed
ventral side uppermost, and held in that position by hooks.
The ventral portion of the parasphenoid must be removed
in order to study the course of the internal carotid trunks.
The first and 2nd _ efferent branchial vessels
(Hf. Br. 1, Ef. Br. 2) open separately into the epi-
branchial trunk. The 3rd and 4th (Hf. Br. 3, Hf. Br. 4)
unite together to form a short trunk. On the left side
this opens into the left epibranchial, on the right it opens
into the ccliaco-mesenteric artery (A. em.). It may
appear, however, that the cceliaco-mesenteric, instead of
taking origin from the epibranchial as represented in the
figure, springs from the common trunk of 3rd and 4th
efferent branchials.
Immediately behind the union of the epibranchial
trunks the subclavian arteries are given off from the dorsal
aorta. Hach of these vessels (A. sel.) passes out trans-
versely, then bends down ventrally and runs along the
internal surface of the corresponding pectoral girdle, the
muscles of which it supplies. Behind these vessels trans-
verse arteries are given off from the dorsal aorta on either
side, one to each segment. These vessels are not repre-
sented in the figure.
Several arteries leave the epibranchials to supply the
muscles of the gill arches with blood. The most impor-
tant of these is a paired vessel which leaves the epi-
branchial immediately anterior to the place of entrance of
the 2nd efferent vessel. It passes at first dorsally, then
backwards and downwards over the 3rd and beneath the
4th efferent trunks. Approaching the middle line it runs
SEA-FISHERIES LABORATORY. . 939
ventrally among the muscles on the anterior border of the
pericardium, where it apparently breaks up; a much
smaller vessel takes origin from the dorsal portion of the
lst efferent vessel and runs backwards and downwards
among the muscles of the lst and 2nd gill arches, where
it breaks up. These vessels are represented but not
lettered in fig. 22.
Two fairly large trunks take origin on each side from
the ventral portions of the Ist and 2nd efferent vessels.
Apparently they do not anastomose in Pleuronectes. The
first, which is the hyoidean artery (A. hy.), leaves the
efferent trunk while still within the arch, and efter giving
off a small twig, which breaks up-on the internal surface
of the operculum, turns round dorsally and runs on the
internal surface of the operculum externally to the cerato-
hyal and symplectic bones. At the level of the upper
extremities of the gill arches it breaks up into a number
of branches which end in the filaments of the pseudo-
branch (Ps. Br.).
The Afferent Pseudobranchial Vessel.—The precise
disposition of the afferent pseudobranchial vessels varies
among Teleostean fishes. In the greater number the
afferent vessel is the hyoidean artery, which, moreover,
anastomoses with the circulus cephalicus, so that the blood
in the minute vessels of the pseudobranch may be derived
from that in all the efferent branchial vessels. This is
the arrangement in Gadus. In others, of which Salmo is
an example, the hyoidean artery is the sole afferent vessel,
and does not anastomose with the circulus cephalicus. In
addition to these types of blood supply, Maurer®* has
described another in sow, where the afferent vessel of the
pseudobranch is a twig of the circulus cephalicus and the
* Beitr. zur Kenntniss der Pseudobranchien der Knochenfische, Morph,
Jabhrb., 9 Bd,, pp. 229-252, 1883-4,
240 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
hyoidean artery contributes nothing. In Pleuronectes the
organ is supplied by the hyoidean artery, and there is no
evidence of an anastomosis of the latter with the circulus
cephalicus beyond a doubtful communication between
branches of the hyoidean and external carotid arteries.
The Efferent Pseudobranchial Vessel is the ophthalmic
artery. Blood, after traversing the capillaries in the
pseudobranchial filaments, passes into this vessel (A.op.),
which runs forwards along the roof of the pharynx covered
over by the mucous membrane. The two ophthalmic
arteries approach each other in the middle line of the
body, then separate and perforate the prootics together
with the superior jugular veins, passing through the
jugular foramina (f. jug. fig. 2). Hach vessel accom-
panies the jugular vein and optic nerve of its side, and
reaching the eye perforates the sclerotic and breaks up in
the choroid gland. This peculiar arrangement is common
to all Teleostean fishes, and has not received any satis-
factory explanation. Joh. Miller suggested that the
pseudobranch was a gland furnishing an internal secre-
tion, and that the object of the included capillary system
of the pseudobranch was to equalise the intra-optical
pressure by smoothing down the pulsations of the heart.
But the blood in the ophthalmic artery has already passed
through the branchial capillaries before reaching the
pseudobranch, and there is no evidence of the elaboration
of any internal secretion.
The Pseudobranch.—It will be convenient to give
some account here of the structure of this organ. It is
situated on the inner surface of each operculum in a little
concavity which lies behind the strong transverse muscles
forming the roof of the pharynx, and which is formed by
the abrupt termination of these in a posterior transverse
ridge. It is situated mostly on the hyomandibular, but
SEA-FISHERIES LABORATORY. 241
its ventral extremity les on the preoperculum. It is so
situated that its attached base is exactly opposite to the
dorsal portion of the first branchial arch, and ihe direction
of its filaments is almost exactly that of those of the dorsal
portion of the first holobranch, that is, posterior and
shghtly dorsal. The first branchial cleft is therefore
bounded posteriorly by the anterior demibranch of the Ist
branchial arch and anteriorly by the pseudobranch. The
afferent pseudobranchial vessel or hyoidean artery runs
along the external or deep-seated part of the base of the
pseudobranch, and gives off a vessel to each filament.
The efferent pseudobranchial vessel or ophthalmic artery
runs along the internal or visible part of the base, and
receives a vessel from each filament.
The filaments of which the pseudobranch is composed
are strikingly similar in appearance to those of any one of
the true demibranchs, and their structure is the same in
all essential points. Hach is made up of a flattened axis,
on each side of which are borne a number of lamelle.
The afferent filamentar vessel runs down the internal
(with respect to the attachment of the organ to its arch)
edge of this axis; the efferent vessel runs up the external
edge. Small twigs are given off from the afferent vessel
into each lamella, and in each of the latter they break up
into a capillary plexus, as in the true gills, which empties
its blood into a corresponding twig opening into the
efferent filamentar vessel.
Only about one-half of each filament projects freely
into the opercular cavity. The basal halves are all
attached to each other and to the epithelium clothing the
inner surface of the operculum. The lamelle are mostly
free, but many are attached together by their edges.
They differ from the lamelle of the true gills in that
their wall instead of being a squamous epithelium is made
i
942 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
up of nearly cubical cells and contains numbers of goblet
cells, in this respect resembling the general wall of the
pharyngeal cavity or the epithelium covering the bran-
chial arches. pig
Probably the pseudobranch is not a _ functional
respiratory organ, though its structure is very similar te
that of any demibranch of the posterior series of true gills.
The walls of the vascular lamelle resemble mucous
epithelia rather than membranes through which gaseous
interchange may take place. And the blood reaching the
organ has already passed through respiratory plexuses in
the first holobranch. Undoubtedly it is part of the holo-
branch which was formerly situated on the hyomandibular
arch, and its situation suggests that it is the posterior
demibranch of that gill. There are no traces of the pre-
sence of a vestige of the anterior demibranch of this gill,
and the structure of the organ is exactly that of a demi-
branch, the respiratory surfaces of which are greatly modi-
fied. Since no traces of the afferent vessel originating in
the ventral aorta, which would have supplied a functional
hyomandibular gill, are present, the vascular supply
gives no certain indication of the homology of the
organ.*
The Pelvic Artery.—Hach of the 2nd efferent bran-
chial vessels gives origin to an artery which almost imme-
diately unites with its fellow of the opposite side, and the
azygos trunk so formed runs backwards in the floor of the
pharynx in the middle line of the body. Various small
vessels are given off to the ventral portions of the branchial
arches. This pelvic artery (A. pe.) then gives origin to a
small vessel supplying the pericardium, the pericardial
artery (A. per.), and continues backwards between the
* Cp. the cranial nerves for a discussion of the nerve supply of the
pseudobranch.
SEA-FISHERIES LABORATORY. 243
pelvic arches almost to the musculature of the body wall
surrounding the anus.
The Carotid Arteries—The portion of each epi-
branchial artery anterior to the entrance of the Ist efferent
branchial vessel may be spoken of as the common carotid
artery. It is a very short trunk which divides into two
vessels. The outer of these, the external carotid
(A. Car.*), curves round behind the pharyngo-branchial
segment of the lst branchial arch, and runs forward on
the ventral surface of the skull. Several branches are
given off which break up on the internal surface of the
operculum and on the base of the skull. The internal
branches of the common carotids, the internal carotid
arteries (A. car.), after perforating the skull at the junction
of the prootics and parasphenoid by the carotid foramina
(f. car. fig. 2), communicate by a very short anastomos-
ing vessel (Cz. c.) which completes the circulus
cephalicus. From this transverse anastomosing vessel
three arteries take origin, which run anteriorly in the
trough of the parasphenoid. ‘The two external vessels,
which are the internal carotid arteries, 1un forwards
towards the nasal region of the skull. The internal
median vessel divides, and the two vessels so formed run
forwards in the trough of the parasphenoid, or eye muscle
canal, accompanying the eye muscles. Hach passes out
with the corresponding optic nerve, and runs forwards
towards the eye.
The Visceral Arteries.—The cceliaco-mesenteric artery
(A. cm.) is an unpaired vessel lying entirely to the right
side of the body. After leaving the right epibranchial
artery it passes over the external surface of the right
precaval vein, and gives off a small branch—the cesopha-
geal artery (A. w.), which breaks up on the wall of the
esophagus, It then almost immediately bifurcates, and
244 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
from the point of division the celiac artery (A.ce.) is
given off. From this artery a small vessel arises (A.hep.)
which turns backwards and enters the liver on the pos-
terior surface of that organ. ‘The two celiaco-mesenteric
trunks then pass internally to the right lobe of the liver.
One vessel runs in the mesentery, giving origin to
branches which supply the greater portion of the intestine
from the anus forwards. The other courses in the mesen-
teric sheet connecting the liver with the duodenal
loop, and supplies that portion of the intestine and
the stomach. |
The dorsal aorta gives origin to a pair of arterial
trunks in each segment, which supply the muscles of the
trunk. Towards the posterior extremity of the kidney, a
large median vessel—the common genital artery (A. gen.)
—is given off, and passes downwards through the posterior
portion of the kidney, sending small branches to the
kidney and suprarenal bodies. This divides into two
branches, one of which goes to each ovary or testis and the
adjacent portions of the body wall. The dorsal aorta then
passes backwards to the tail in the tunnel formed by the
haemal arches.
With regard to the venous system, we propose to”
describe the larger venous trunks only. All the blood
from the head‘is returned to the heart via the paired
superior and the unpaired inferior jugular veins.
The Superior Jugular Veins (V. Jug.) are large thin
walled vessels which will have been exposed in dissecting
for the branchial vessels. They receive the blood from
the eyes and adjacent parts, and accompany the eye
muscles in the eye muscle canal, emerging from the latter
through the jugular foramina (/. jug. fig. 2). They then
run backwards on the ventral surface of the skull over the
dorsal extremities of the branchial vessels slightly dorsal
SEA-FISHERIES LABORATORY. DAD
and external to the epibranchial arteries, receiving in
their course vessels conveying blood from the head and
brain, and enter the precaval veins at the dorsal and
anterior extremities of the latter.
The Inferior Jugular Vein (V. Jug.1) is an azygos
trunk running backwards under the ventral wall of the
pharynx immediately above the dorsal aorta. It then
passes upwards on the anterior wall of the pericardium,
and may enter either the right or left side of the sinus
venosus, though its ending on the right side seems to be
the more common one.
The Hepatic Veins (V. Aep.) are short wide trunks
coming from the liver, which penetrate the posterior wall
of the pericardium and enter the posterior part of the
sinus venosus.
The Renal Portal System.— The afferent vessels of this
system are the parietal veins, the caudal vein and the
genital veins. The caudal vein (V. cd.) runs forwards
from the tail in the haemal canal immediately beneath
the dorsal aorta. It enters the kidney at the most dorsal
and posterior angle of the latter organ, and divides into
two vessels which run forwards in the kidney and break
up, but do not apparently anastomose with the cardinal
vein. A short venous trunk comes from each ovary (or
testis) and the adjacent portions of the body. wall, and
enters the kidney on each side near the extreme ventral
tip of the latter organ. A series of veins from the muscles
of the trunk enter the dorsal portion of the kidney on each
side; these are the parietal veins. One such vessel is
represented in fig. 22 as entering the anterior tip of the
head kidney.
The efferent. vessels of the system are the cardinal
veins, which run forward in the kidney. The right car-
dinal vein (V. card.) runs along the middle part of
246 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
the kidney, and is visible on its ventral surface. We have
said that the kidney at its anterior extremity is divided
into two horns, which reach forward towards the heart.
The right cardinal vein emerges from the kidney through
the right horn and enters the posterior side of the right
precaval vein. ‘The left cardinal (as in the Cod) is a short
vessel which begins at about the anterior third of the
kidney, traverses the left horn, and enters the posterior
side of the left precaval vein. The two cardinals do not
apparently anastomose with each other.
The Hepatic Portal System. —The afferent vessels of
this system are the portal veins carrying the blood from
the stomach, intestine and spleen. The smaller factors of
this system have much the same course and distribution
as the branches of the celiac and cceliaco-mesenteric
arteries. They do not, however, unite to form a single
hepatic portal vein, but enter the liver as a variable
number of separate portal veins. Commonly there are
(1) a trunk receiving the blood from the spleen and the
greater portion of the intestine, and anastomosing with
(2) a vein receiving the blood returned from the loops of
the intestine posterior to the pylorus; (3) a smaller vessel
draining the region of the pylorus, and (4) a vein coming
from the stomach. These vessels enter the internal sur-
face of the liver principally on the larger left lobe, and
run for some distance parallel to and immediately beneath
the surface, so that their ramifications can be easily traced.
Their precise number and distribution in the liver varies ;
five such trunks are represented in fig. 21, cut off close to
the liver surface (Vp.) The apparent calibre of the intes-
tinal veins, and to a less extent the arteries also, is
increased by the presence of the perivascular glandular
tissue referred to above. ‘The efferent vessels of the
hepatic portal system are the two large paired hepatic
SEA-FISHERIES LABORATORY. IAT
veins (V. hep.) which enter the lower portion of the sinus
venosus on its posterior side.
E.—THE NERVOUS SYSTEM.
We shall commence our description of the nervous
system with the brain and spinal cord, then proceeding to
the cranial and spinal nerves, and finally to the
sympathetic nervous system.
1.—TuHeE BRAIN AND SPINAL Corp.*
(Figs. 28, 30, 31).
The brain of the Plaice may be conventionally
divided into four regions, including the following
structures : —
A. Hind -Brain-—This comprises the medulla
oblongata, which itself includes many structures that can
only be regarded as the continuations of corresponding
ones in the spinal cord, and the cerebellum. The latter
consists of a body and the anterior valvula cerebelli.
~ 5B. Mid-Brain. —Formed by a base (crura cerebri) and
side wall, and the tectum opticum or tectum mesencephali
(optic lobes). )
C. "Tween-Brain.—lRepresented by three parts: (1)
the epithalamus (epiphysis generally and the ganglia
habenulz); (2) the thalamus (optic thalami—thalamence-
phalon); (3) the hypothalamus (corpus geniculatum,
* The following works will be found to contain references either to the
brain of the Plaice or to allied Pleuronectids :—Cattie, Arch. Biol., ii1.,
p. 150; le Roux, ‘‘ Recherch. Syst. Nerveux Téleostéens,’’ Caen, 1887
Mayne, ‘‘ Optic Nerves,’’ Todd’s Cyclopedia, part xxvi.; Malme, Bihang
K. Svens. vet.-akad Handlingar, xvii.; Mayer, Verhand. K. Leop.-Carol.,
xxx.; and Steiner, ‘‘ Entstehung d. asymmetrischen Baues der Pleuronec-
tiden,” 1886 ; a recent important work, by J. B. Johnston, on the brain of
Acipenser (Zool. Jahrb., Abth. Morph., xv.), may be used as a starting
point in studying the brain of Fishes in detail.:
948 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
corpus mammillare, infundibulum, lobi inferiores, saccus
vasculosus and pituitary body).
D. Fore -Brain.—This may be considered as including
the epistriatum, striatum proper and the membranous )
pallium, together with the bulbus olfactorius.
The roots of the cranial nerves will be described in
the section on the nerves.
In a dorsal view of a well-preserved brain we note the
following characters :—First the relatively small size of
the brain. This is seen also in the Cod and in Teleosts
generally. The small brain lies in the large cerebral
cavity, surrounded by a packing of areolar connective
tissue loaded with fat, and seems to be very dispropor-
tionate to the size of the fish. Then the asymmetry of it
is at once striking. The spinal cord, on entering the
brain case, turns slightly to the left, but opposite the
cerebellum it swerves markedly to the right, so that a
median line would pass through the left striatum instead
of between the two striata.
In the medulla the great reduction of the terminal
bud system that has taken place involves the absence of
the lobi vagi. Also the lateral line system is not suffi-
ciently robust to have produced that exaggeration of the
tuberculum acusticum known as the lobus linez lateralis.
The medulla is therefore smooth, and presents no obvious
traces of its ganglia. On removing the vascular covering
of the fourth ventricle known as the choroid roof, the
ventricle itself is seen to be apparently divided into two
parts by the partial union over its roof of the medio-lateral
portions of the tuberculum acusticum, forming an elliptic- —
| shaped opening behind (calamus scriptorius) and a
triangular one in front, with its apex directed backwards.
The cerebellum, of which the body only is visible in the
undissected brain, is small and globular. This is what
SEA-FISHERIES LABORATORY. QA9
one would expect, seeing that it is connected with the
general activity of the organism, and the Plaice is sluggish
in habits.
The mid-brain is represented on the dorsal surface on
each side by the tectum opticum (optic lobe). These are
very large bodies almost spherical in shape, and charac-
terised in dead and preserved specimens, and doubtless in
life also, by a deep furrow, which extends backwards in a
curve from the anterior margin of each lobe for about half
its antero-posterior diameter.
As is usual in Teleosts, the “tween-brain hardly
appears at all on the dorsal surface of the brain, being
excluded from it by the meeting of the two striata and
optic lobes. However, a small portion of its membranous
roof is visible, and from this there is seen emerging by
the triangular space formed immediately in front of the
median apposition of the two optic lobes, the extremely
fine pineal tube. Im sections it is seen to arise as an
evagination of the roof of the third ventricle almost
behind the ganglia habenul and in front of the posterior
commissure. It then passes forwards over the pallium of
the left striatum and swells into the large pineal gland
lying on the pallium near the anterior extremity of the
left striatum. By pressing apart the optic lobes there
may be seen immediately in front of the exit of the pineal
tube the ganglia habenulew and the plaited choroid roof of
the third ventricle.
In a well-preserved brain the membranous pallium of
the fore-brain is very obvious. It is a large oval sheet,
with its long axis at right-angles to that of the brain, and
almost equal to that of the optic lobes. It is a very thin
membrane, and appears thicker than it really is on account
of the coagulated cerebro-spinal fluid in the ventricle.
The corpora striata are also visible through the pallium.
250 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
On removing the pallium, it will be noted that there are
no lateral ventricles, but a large single median prosocoele.
In the floor of this are raised up the large corpora striata
separated dorsally by a wide fissure, but connected below
by the anterior commissure, and constituting the solid
cerebral hemispheres of older authors. These are con-
siderably smaller than the optic lobes, and the dorsal
surface of each is marked by a somewhat complex furrow
(“sulcus ” of former authors—see fig. 30). In front of
and below the striata are the olfactory bulbs, from which
the olfactory nerves originate. The left is smaller than
the right.
On the ventral surface of the brain the most notice-
able structures are the appendages of the ‘tween-brain.
The lobi inferiores are a pair of large bean-shaped bodies
opposed by their median surfaces. In the middle line
immediately in front of these is the spherical pituitary
body. The apposition of the pituitary body and lobi
inferiores is not complete, and a triangular space is left
by which there emerges on to the ventral surface of the
brain the red thin-walled saccus vasculosus. This is at
its origin a very narrow tube, but it expands and passes
straight backwards in the middle line over the opposed lobi
inferiores. It is dilated behind, and ends blindly slightly
posterior to the hinder border of the lobi inferiores. In
the adult the pituitary body (lypophysis cerebri) and
saccus vasculosus are essentially glandular organs receiv-
ing a marked nervous supply from the infundibulum.
According to most recent authors the saccus at least
“probably forms part of a mechanism for secreting, or
otherwise controlling the pressure of, the cerebro-spinal
fluid. It may affect the heart beat and blood pressure by
way of the vagus’ (J. B. Johnston).
The crossing of the optic nerves is very obvious in the
SEA-FISHUERIES LABORATORY. 951
Plaice, as it is effected some distance in front of the
pituitary body, and is not hidden by the olfactory nerves
on the ventral surface. It is also quite clear that they
merely cross and do not exchange fibres, whilst their
plaited nature is at once revealed by a little simple dissec-
tion. On removing the optic nerves the two small and
asymmetrical olfactory bulbs are well seen lying largely
under the anterior extremities of the two striata. In the
medulla the ventral fissure of the spinal cord is continued
as far forwards as the base of the lobi inferiores, where it
slightly expands.
Regarding the ventricles of the brain, the central
canal of the spinal cord appears in the sections as a pin
hole. It begins to widen rapidly into the fourth ventricle
(myelocoele) at about the posterior region of the auditory
organ. The ventricle is at first very deep from above
downwards and very narrow from side to side. It soon
opens above, and is only closed in by the choroid roof.
The peculiarity of the roof of this ventricle has been
already mentioned. In front of the expanded portion it
becomes completely roofed over by the tuberculum
acusticum, and at the same time is reduced to a very small
size. Opposite the junction of the medulla and cere-
bellum it again expands, but does not communicate with a
cerebellar cavity (metacoele), the cerebellum being solid.
In front of the body of the cerebellum it passes into the
aqueductus Sylvii (mesocoele—iter a tertio ad quartum
ventriculum), roofed over behind by the valvula cerebelli
and communicating on each side and in front with the
large space enclosed by the tectum opticum (optocoele).
In front, the latter opens below into the third ventricle
(thalamocoele), bounded laterally and below by the
thalamus (optic thalami) and above in front by the choroid
roof. ‘he third ventricle is prolonged downwards and
252, TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
somewhat backwards into the hollow infundibulum. If
this be now traced posteriorly, it is found first of all to
communicate with the cavity of the pituitary body.
Almost at the same time, but more dorsally, it is pro-
longed on each side into the large cavities of the lobi
inferiores, whilst finally it communicates with the cavity
of the fine stalk of the saccus vasculosus. The third
ventricle therefore is continuous with the cavities of the
pituitary body, lobi inferiores and saccus vasculosus. The
infundibulum of the Plaice is difficult to delimit, as it is
largely merged into the floor of the thalamus. Inciden-
tally we may draw attention in the latter to the very large
paired nucleus rotundus, which is very striking in sec-
tions. Anteriorly the third ventricle passes into the large
median ventricle of the fore-brain (prosocoele), roofed over
by the pallium. The prosocoele is not prolonged into the
bulbi olfactorii as a rhinocoele, the bulbs being solid.
Cunningham makes two assertions on the brain of the
Sole that appear to us to require confirmation. One is
that the “position of the brain is almost entirely
unaffected by the change which has taken place in the
normal position of the fish,” and the other is that “ the left
olfactory lobe is somewhat larger than the right, a differ-
ence which is related to the great development of the left
olfactory capsule.’ On the other hand, Malme states of
the Sole (op. cit., p. 34) that “ insbesondere
ist der rechte Lobus [striatum] (derjenige der Angeubeaaa
viel grésser als der linke,”’ and again that in Pleuronectids
generally “‘der Bulbus der Augenseite ist stets der
grosste.’”” Malme’s observations agree with ours on the
Plaice. Again, Cunningham apparently overlooks the
work of Rabl-Riickhard on the brain of Teleosts, and
describes what are really the corpora striata as receiving
prolongations from the third ventricle.
SEA-FISHERIES LABORATORY. 253
In the Spinal Cord we wish to direct attention to two
peculiarities only. The first is the giant ganglion cells
that are found in the dorsal fissure. Transverse sections
of the cord will demonstrate these quite easily. They
have been studied especially by J. B. Johnston,* Sargentt
and Dahlgren.t The latter author, who has devoted his
attention particularly to the Pleuronectide, states that
these very peculiar cells are the first ganglion cells to be
differentiated in the embryo flat-fish, and that they become
an important and permanent apparatus in the adult. In
an adult fish they are seen to form a row of very large
nerve cells in the median dorsal fissure, and their neurites
pass backwards to form an isolated fibre tract on the
median side of each dorsal horn. Their exact distribution
and function are unknown, but Dahlgren suggests that
the neurites pass out with the dorsal roots of the spinal
nerves and are connected with the sensory supply of the
unpaired fins. Sargent finds in Ctenolabrus that the giant
cells are connected with a fibre bundle passing forwards
through the cord and medulla, and emerging by the
ventral root of the trigeminus nerve. If this be true then
the fifth nerve of this fish possesses a nerve component not
hitherto recognised, and it would be interesting to study
the giant cell apparatus from the point of view of the
component theory.
The second peculiarity of the cord is one which it
shares with all Teleosts, and that is in the presence of the
very interesting rod or fibre within the lumen of the
central canal known as Reissner’s fibre. This fibre has
been investigated recently by Sargent,§ who finds that it
“ extends through the whole length of the canalis centralis
* Jour. Comp. Neurol., x., p. 375. t Anat. Anz., xv., p. 212.
t Anat. ae. RHigp. 201.
§ Anat, Arz., xvil., p. 33, and Proc. American Acad. Arts and Science,
xxxvi., No. 25.
254 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
of the cord and continues cephalad through the 4th and
3rd ventricles to the anterior end of the optic lobes,”
where it passes into the brain tissues. It is not a single
fibre, but a collection of axis cylinders, and is therefore a
fibre tract. Some of the fibres in the tract originate in
cells situated at the posterior extremity of the central
canal, and pass forwards to the tectum opticum. Others
originate in cells in the tectum opticum and pass back-
wards as far as the “ posterior canal cells.” The tract,
therefore, contains fibres coursing in two opposite direc-
tions. According to Sargent this unique apparatus forms
a “short circuit between the visual organs and the muscu-
lature, and has for its function the transmission of motor
reflexes arising from optical stimuli.” It is most highly
developed in active fish, and is entirely absent in the blind
vertebrates of the cave fauna.
2.—THE Cranial Nerves (Fig. 23).
In spite of the fact that the cranial nerves of Fishes
have been more or less investigated for about two and a
half centuries, it is only within the last few years that our
knowledge of them has assumed a form likely to be at all
lasting. Although these results were made possible as
long ago as 1811 by the enunciation of Bell’s law, and
although this law was very ingeniously developed and
applied to Fishes in 1849 by Stannius, who has never
received due credit for his work, it was only in the
eighties that Gaskell stated his ‘‘ four root theory ” of the
spinal nerves, which showed that there were represented
in each spinal nerve four kinds of fibres instead of the two
assumed by Bell’s law.
The attempt to strictly apply the four root theory to
the cranial nerves of lower vertebrates has not only been
SEA-FISHERIES LABORATORY. 255
unsuccessful, but it has actually retarded knowledge by
diverting the energies of investigators into an unprofitable
channel. The work on the cranial nerves of the frog’s
tadpole, published in 1895 by Strong, distinctly proved
this, for he showed that, for example, there were three
systems of sensory fibres in the cranial nerves of the larval
frog, one of which must be considered characteristic of the
head and not represented in the spinal nerves at all, and
another only partly so.
One of the first results of Strong's work was to show
that the old system of classifying the cranial nerves of
Fishes into ten formal pairs was essentially unsatisfactory,
and that attention should be concentrated rather on the
various definite systems of nerve fibres characterised by
their structure, central origin and peripheral distribution,
than on those heterogeneous collections of nerve rami
“cranial nerves.” We must, however, in
known as the
the meantime adhere to the old classification, until suffi-
cient work has been carried out on the new lines to justify
a revision of the cranial nerves, and to ensure for its
findings some permanent value. |
The new theory of the cranial nerves is lena as the
“component theory.”’ It takes advantage of the fact that
the fibres forming them, and omitting the olfactory and
optic nerves and the sympathetic, which present problems
of an altogether special nature, fall by reason of their
functions and certain structural relations into five fibre
systems, three of which are sensory and two motor. Tach
system is delimited by a uniformity of peripheral ter-
mination and a special and characteristic origin in the
brain, and each system may appear in a variable number
of cranial nerves as a component of those nerves. It is
therefore indispensable, as we have done in the Plaice, to
work out the whole course of the nerves by means of serial
256 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
sections. Microscopic work either on the brain or the
peripheral nerves only is inadequate, and dissection, as a
means of research, has but a very doubtful value. The
only fish which has been thoroughly investigated according
to the component theory is Menzdia—in an important
work published recently by C. J. Herrick, who truly
remarks: ‘‘ Until each component can be isolated and
treated as a morphological unit, and then unravelled in its
peripheral courses through the various nerve roots and
rami—until this is possible, no further great advances
in cranial nerve morphology can be looked for even among
the lower vertebrates, still less in man.”
The five systems of fibres which variously compose
the cranial nerves of the Plaice are as follows :—
1. General Cutaneous or Somatic Afferent System.—
These fibres, which undoubtedly correspond to the
cutaneous fibres of the spinal nerves, are derived from
continuations of the dorsal horns of the spinal cord, which
form two longitudinal bundles in the medulla known as
the spinal vth tracts. These fibres in the Plaice leave the
brain by the roots of two cranial nerves only—the vth and
the xth. In the former case their ganglion is the Gasserian
ganglion, in the latter the jugular ganglion. The
cutaneous fibres in the facial nerve are distinctly derived
from those of the fifth. The fibres of this system are
distributed generally to the skin, and do not end in any
specialised dermal sense organs. Hypertrophy of this
system produces a corresponding hypertrophy of its centre
in the central nervous system, as witness the remarkable
lobes at the anterior extremity of the spinal cord of
Prionotus (Morrill).
2. Somatic Efferent System.—Represented by the
heavily myelinated eye muscle nerves (il1., iv. and vi.).
This system is of course largely present in the so-called
SEA-FISHERIES LABORATORY. 257
“hypoglossal” nerve, or first spinal, but we do not con-
sider this to be a cranial nerve in fishes.
3. Communis (Viscero Afferent?) System. — Partly
synonymous with the fasciculus communis system of
Osborn and Strong. A striking feature about this sensory
system is that it may innervate both ecto- and endo-dermal ~
surfaces, and it may therefore be disputed whether it is a
visceral nerve that has invaded the skin, a somatic nerve
that has invaded the visceral surfaces, or a complex of
more than one component. ‘The latter seems perhaps the
most probable. The fibres of the communis system are
fine and lghtly myelinated, and are distributed
peripherally as follows :—(a) to the special sense organs in
the outer skin called “‘ terminal buds,” 7.e., to all the
definite sense organs of the skin not belonging to the
lateral line system. This part of the component has been
reduced in the plaice; (b) to taste buds in the mouth;
(c) to the general mucous surfaces without the interven-
tion of sense organs at all. The ganglia and cranial
nerves into which the system enters are: (a) the genicu-
late ganglion (vii.), glossopharyngeal ganglion (ix.), and
the intestinal and four branchial ganglia of the vagus (x.).
Any communis fibres in the trigeminus arise from the
communis facialis. The central origin of the component
is the Lobus vagi, and the enormous vagal lobes of
Carpiodes are simply due to the hypertrophy of the com-
munis vagi component in this fish (Herrick), Further the
so-called Lobus trigemini of some fishes (Amzurus) is due
to the hypertrophy of the communis facialis, and hence it
should be called Lobus facialis.
4. Wiscero Efferent System.—This comprises the
motor roots of the vth, viith, ixth and xth cranial nerves.
Each of the first two has its own motor nucleus in the
brain, but the two latter arise from collections of cells
U
258 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
supposed to represent the nucleus ambiguus. The fibres
of this system are heavily myelinated.
5. Acustico Lateral System.—Includes the auditory
and lateral line nerves. Let it be emphasised at once,
what is taking a long time to filter down into the text-
books, that the lateral line nerves can only be associated
with two cranial nerves—the viith and xth. The lateral
line fibres in the fifth nerve are always derived from the
facial, those in the ixth (when present) from the vagus.
The fibres of this system are distributed to the ear, to the
sense organs in the lateral line canals, and to those lateral
line sense organs lying free on the skin, and known as
pit-organs. Its ganglia are the dorsal and ventral lateral
ganglia of the facial, and the lateralis ganglion of the
vagus, and its fibres are very large, being in fact the
coarsest in the body. Its central termination is the tuber-
culum acusticum of the antero-dorsal region of the
medulla—associated with the cerebellum. ‘The hyper-
trophy of the lateral line nerves produces an exaggeration
of the tuberculum acusticum well marked on the surface
of the brain and called by Johnston the Lobus lnez -
lateralis. This lobe has also been called the Lobus trigemin1i
by the older writers, and when associated with lateral line
fibres it may well receive the name given it by Johnston.
Otherwise it should be called the Lobus facialis (see above).
Nervus Olfactorius*—l. (Figs. 25 and 28.)
As considerable asymmetry is exhibited by these
nerves, both sides will be described.
*For the cranial nerves of Teleostean Fishes compare especially the
following works ;—Allis (Amia), Jour. Morph., ii. and xii. ; Cole (Gadus),
Trans. Linn. Soc., ser. 2, vii.; Desmoulins and Magendie (nerves of
Rhombus), Anat. Syst. Nerveux, Paris, 1825; Herrick (Menidia, Gadus,
and Amiurus), Jour. Comp. Neurol., ix., x., and xi.; Juge (Szlurus), Rey,
Suisse Zool., vi; and Stannius (general), Rostock, 1849. The works of
Herrick are most important so far as the Plaice is concerned, and should
certainly be consulted. We have purposely adopted, as far as possible, the
same reference letters, in order that the comparisons maybe facilitated.
SEA-FISHERIES LABORATORY. 259
The right Bulbus olfactoriust lies mostly under the
corpus striatum (the latter is the cerebral hemisphere of
older authors). Behind, it is free, unconnected with the
striatum and ends bluntly, but in front it acquires a firm
connection with the striatum. Anterior to this again it
separates once more from the striatum. So far it has been
increasing in size, but it now begins to taper down, its
ventral portion becomes fibrous, and its dorsal divided
into two. The upper or cerebral portion disappears in
front, and the remainder narrows down into the cylindrical
nervus olfactorius. Both olfactory nerves lie to the right
of the upper or left optic nerve. As the nerve passes
forwards it becomes divided by connective tissue strands
into two or more fasciculi, each of these again being
further subdivided into small bundles of fibres. The
right olfactory passes through the foramen olfactorium in
the right prefrontal, turns up at once and breaks up in
the olfactory laminze of the right nasal chamber.
The left Bulbus olfactorius is not free behind like the
right, but passes imperceptibly into its striatum. Nor is
it situated below the latter, but between the two striata
(see fig. 28). The appearance therefore of this portion of
the brain is very asymmetrical, and suggests a rotation
towards the right side of the ventral axis of the brain
only. The left bulbus is perceptibly smaller than the
right, but the left striatum extends further forwards than
its fellow. The bulbus separates from the striatum in
front, becomes fibrous at its right ventral corner and gives
off the left olfactory nerve, which passes at once to the
right side, so as to lie near the right bulbus. The left
+ This structure is also called by some authors the Tuberculwm
olfactoriwm (Stannius) and Lobus olfactorius. We have no space to discuss
the precise significance of each of these three terms, if indeed they have
any (but see Elliot Smith, Jour. Anat. and Phys., xxxv., 1901).
960 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
bulbus has no direct connection with its nerve in front as
on the right side, nor does it extend as far forwards as the
right one. There is much more difference in the size of
the two olfactory nerves than one would expect from the
sizes of their bulbs; the left being only } the size of the
right. Nor do its fibres take such an intense stain with
the osmic acid. For some distance the two olfactory
nerves course together, but finally the left separates from
the right and passes upwards towards the eyeless side of
the body. It then traverses the olfactory foramen in the
left prefrontal, and at once passes straight upwards to
break up in the olfactory lamine of the left nasal
chamber. The left nasal organ is much smaller than the
right (cp. fig. 25, n. olf., n. olf.1), and hence the small left
nerve. It is also situated somewhat behind the right, and
therefore the left olfactory is the shorter of the two.
Nervus Opticus—Iil.
As in all lower vertebrates, the fibres of the optic
nerve arise mostly from the roof of the mid-brain (tectum
opticum), and as is usual in Teleosts they pass forwards
over the ventricle to collect at the anterior extremity of
the optic lobe, and then course sharply downwards and
forwards to reach the surface of the brain. The optic
chiasma is a simple crossing without any intermingling of
fibres, so that the nerve to the right eye, for example, arises
exclusively from the left side of the brain. As in Menzdira
the nerve to the left eye 1s uppermost at the crossing.
Hach optic nerve, as is usual in Teleosts, consists of a thin
wide ribbon so thrown into longitudinal folds as to form
a round nerve, and each exhibits 34 folds.* If the optic
nerve could be flattened out the width of the ribbon would
* The number of the folds increases with the size of the nerve, judging
from our sections of young plaice at different stages, and also from the
condition in the adult (see fig, 28).
SEA-FISHERIES LABORATORY. 261
be about 2 of the maximum thickness of the body. Fora
time the right optic nerve lies directly under the left, and
both immediately under the right bulbus olfactorius. The
right passes straight out to its eye, but the left curves
over towards the left side. Both reach the eye at about
the same level, perforate the sclerotic and retina, and
spread over the concave surface of the latter in the usual
way.
Owing to the fact that the left eye is situated over the.
right, the optic chiasma is less emphasised in the Plaice
than in a symmetrical fish.
We now proceed to the description of the eye muscle
nerves (fig. 23), taking them in their numerical order.
Nervus Oculomotorius—Ili.
The nucleus of the third nerve (iii.) lies dorsally on
the floor of the mesocoele very near the middle line, and
mostly just over the fasciculus longitudinalis dorsalis.
There is no crossing as in the case of the patheticus. ‘The
fibres of the right oculomotor curve round the fasciculus
and pass backwards and downwards through the brain
substance, to emerge as a large nerve on the ventral
surface of the brain just above the lobi inferiores. Imme-
diately it leaves the brain the nerve takes a sharp turn
forwards, and in due course fuses with the patheticus. It
passes downwards on the outer side of the lobus inferioris
and between this and the v.-vii. complex. After liberating
the patheticus again it courses downwards inside the skull,
passes through the meninges, and enters the cup-shaped
cavity formed by the parasphenoid and known as the eye
muscle canal. Here it divides into a smaller upper and a
larger lower nerve. Now the oculomotor consists mostly
of large and well myelinated fibres, but it also contains
262 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
some small lightly staining fibres. These are for the most
part handed over to the lower nerve, and collect at its
outer side. Finally they pass over into the ciliary
ganglion and hence form the radix brevis (fig. 26, ra. 6.)
of that ganglion.
The upper division of the vdalomatan (r.s.) passes into
the Rectus superior muscle of the eye. Its small fibres
are distributed to the smaller fibres of its muscle.
The lower division soon after leaving the ciliary
ganglion, to which it has been closely opposed, passes
sharply downwards and forwards accompanied at first by
the ramus ciliaris brevis from the ciliary ganglion (fig. 26,
cul. 6.). It splits into three almost equal branches, which
soon take up the following positions in the vertical pas
and are as below: —
(a) Dorsal branch (r. zt.). To rectus internus. Passes
upwards and inwards and reaches the ventral surface of
the [ower or right optic nerve. It subsequently breaks up
in its muscle between and below the two optic nerves.
(6) Intermediate branch (r. zf.). To rectus inferior.
Divides into three principal twigs which enter their
muscle in the order shown in the figure.
(c) Ventral branch (0.2.). To obliquus inferior.
Descends and crosses the palatinus vil. internally and for
some distance lies just below and internal to it. It then
rises, crosses the palatine again, and now lies to the inner
side of the rectus inferior. From this point it courses
almost straight forwards at the right side of the
parasphenoid and ethmoid cartilage, and finally splits up
to enter its muscle in the way shown in the figure.
As regards now the left side, it may be noted at once
that the distribution of the eye muscle nerves, except
those coursing far forwards like the patheticus and the
branch of the third to the inferior oblique, is not much
SEA-FISHERIES LABORATORY. 263
affected by the torsion of the head, since the parasphenoid
and its eye muscle canal are simply rotated en bloc to the
right along their longitudinal axes. The distribution of
the nerves is therefore the same, except that those of the
left side have been swung upwards so as to lie nearer the
dorsal edge of the body, and hence above those of the right
side. In the case of the branch to the inferior oblique
this rotation has caused the left one to be situated at first
much above the right. In front, however, it begins to
turn downwards towards the parasphenoid, and the right
one at the same time rising, they eventually take up cor-
responding positions at the sides of the parasphenoid and
ethmoid cartilage. Finally the left turns upwards to
reach its muscle in which it breaks up in much the same
way as the right. Neither of the long eye muscle nerves
(patheticus and the branch just described) of the left side
reaches, at its final distribution, a much higher transverse
level than that of the right.
If a comparison be made with the eye muscle nerves
of Menidia, as described by Herrick, it will be seen that
in the two forms the relations of the nerves are essentially
the same.
Nervus patheticus s. trochlearis—lV.
The fourth nerve of the right side (iv. 0.s.) consists of
many large and a few small fibres all heavily myelinated.
It has no connection with the communis vil. as described
by Herrick in Menidia. The nucleus of the pathetic is
situated dorsally close behind that of the oculomotor. The
two pathetic nerves cross over the mesocoele as in all
hitherto investigated vertebrates, so that, for example, the
right nerve arises from the left side of the brain. The two
nerves pass first backwards, then rise sharply over the
mesocoele, cross, and leave the brain almost in the same
264 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
section so as to he wedged in between the axis of the brain
and the optic lobe. It at once turns sharply downwards
and forwards, and becomes closely opposed to the dorsum
of the oculomotorius. For some sections the two nerves
can be distinguished, but in front they appear to fuse
completely, and cannot be distinguished even under the
high power. ‘The pathetic is, however, given off again
from the dorsum of the oculomotor, passes forwards and
downwards, pierces the membranous wall of the brain case
obliquely in front, and breaks up in the superior oblique
muscle of the eye as shown in the figure.
On the left side the relations of the nerve to the brain
and for some distance in front are essentially the same as
on the right side. As, however, it approaches the eyes
(section 392 of chart), it begins to pass towards the lower
or right optic nerve) Subsequently it takes up a position
above and to the left of the upper or left optic nerve,
having now crossed over the top of the parasphenoid and
lying distinctly to the right of the morphological middle
line. The two optic nerves having dipped down the left
pathetic crosses over the left optic to its right side. The
left optic now turns upwards towards its eye, so that the
left pathetic lies considerably below it. The latter after-
wards passes upwards to the left side of the frontal bridge,
and is seen below the right pathetic. It finally breaks
up in the left superior oblique in much the same way as
the right.
N-ervus’) abduceéens—VL
The sixth nerve (vi. r.e.), which consists mostly of
large well myelinated fibres together with some small —
ones, arises from the medulla by two small rootlets some
distance from the middle line. Both these rootlets have
apparently a common nucleus situated far from the middle
SEA-FISHERIES LABORATORY. 265
line and not far from the ventral surface of the brain.
Soon after leaving the brain the abducens passes sharply
downwards to reach the floor of the brain case. In front
it passes downwards and forwards, perforates the meninges,
enters the eye muscle canal, and at once reaches the
rectus externus muscle which it supplies. The abducens
is the most posterior of the eye muscle nerves (cp. chart),
and on this account the two nerves exhibit practically no
traces of asymmetry.
Before we can proceed to describe the trigeminal and
facial nerves separately, it is necessary to interpolate an
account of the roots and ganglia of the trigemino-facial
complex as a whole (fig. 23).
As in Teleosts generally the fifth and seventh nerves
at their exit from the brain, and also their ganglia, are
so disposed that it is quite impossible to completely
analyse them by dissection. Examination, however, of a
series of Weigert sections enables us to do this without
much difficulty. Macroscopically there are two roots to
the facial nerve and one to the trigeminal, and three of the
four ganglia of these two nerves are compacted together
into one mass. Analysis by serial sections reveals the
following facts : —
The most anterior root of the complex (r.v.) is that of
the trigeminus. It lies, however, largely internal to and
below the second root, so that it is at first not obvious on
dissection, and emerges from the brain just below the
cerebellum. It is the only root of the trigeminus, and
consists of a general cutaneous and a motor component.
The nucleus of the latter les in the floor of the fourth
ventricle, and the fibres pass right through the Gasserian
ganglion first into the Truncus infraorbitalis (¢.cnf.) and
then into the R. Mandibularis V (man. v.). On account
9266 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
of the fact that the large ventral nerve emerging from the
~Gasserian ganglion contains lateral line and communis
components from the facial, the term 7’. ma«dlo-mandibu-
laris, which refers to the unspht RR. maxillaris and
mandibularis V, cannot strictly be apphed to it. The
cutaneous component of the trigeminus arises from the
spinal v. tract, and its ganglion is the Gasserian ganglion.
Ti is distributed to the skin of the face and operculum.
The second root of the complex (r.1.vw.) belongs
wholly to the facial, and consists of 3 roots so closely
packed together that it is difficult to separate them by
dissection. ‘These roots are the dorsal and ventral lateral
line roots and the communis root. The whole arise
together at the same level high up on the medulla and
much higher than and external to the exit of the
trigeminus. ‘The ganglia of the lateral line roots are
respectively the dorsal and ventral lateral line gangha,
and that of the communis root is the geniculate ganglion.
The dorsal lateral line root splits into the Ramus
ophthalmicus superficialis vil. and the R. buccalis vii.,
whilst the ventral lateral line root is continued into the
Truncus hyomandibularis as the R. mandibularis externus
vu. The communis root splits into the communis v., R.
palatinus vu., the R. Posttrematicus vii. and the R.
mandibularis internus vil. Although the three com-
ponents in this root are very compacted they retain their
individuality under the microscope. ‘The communis root
enters the brain first, and then the other two fuse and
enter together behind and above it. The communis root
in the brain passes at once into the fasciculus communis
tract, and the fused two lateral line roots terminate in the
tuberculum acusticum.
The third root of the complex (r.2.vw.). is also
entirely facial and constitutes its motor root. It arises
SEA-FISHERIES LABORATORY. 267
behind the second root and much ventral to it. Its
nucleus lies in the floor of the fourth ventricle very near
the middle line, and the root below joins the ventral
lateral line root preximal! to its ganglion as in Menzdia.
After leaving the brain the motor root, which consists of
deeply staining heavily myelinated fibres, becomes so
confused with the antericr part of the auditory root that
their separation is difficult even with the microscope. The
auditory nerve, however, passes dorsally into the tuber-
culum acusticum, whilst the motor vii. enters the brain
below and immediately in front of it. The motor vu.
passes into the Truncus hyomandibularis.
Of the four ganglia of the complex (g. v.-vii.) only
one remains distinct macroscopically. This is the
ganglion of the dorsal lateral line root, which in front is
situated just dorsal to the Gasserian ganglion, and behind
overlaps externally the root of the trigeminus. It is
entirely intracranial and is partly shown in the chart as
the cells at the base of the R. buccalis vii. The other
three ganglia are crowded between the brain and the skull
wall and apparently form one mass also entirely intra-
cranial except for the narrowed anterior extremity of the
Gasserian ganglion which extends outside the skull along
the R. ophthalmicus superficialis v. as far forward as sec-
tion 472 (cp. chart). When these three ganglia are
examined in serial sections it is seen that the most
anterior is the Gasserian ganglion. ‘This overlaps exter-
nally the geniculate ganglion situated behind it, which in
its turn overlaps externally the ventral lateral line
ganglion—the most posterior of the three. Although the
three ganglia form a single very compact mass, it is not
difficult to define their boundaries, even where, as in the
ease of the first two, the character of their cells is much
the same. In the ventral lateral line ganglion, the cells,
268 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
as is usual in these ganglia, are very small and not
crowded, being scattered among the nerve fibres.
The dorsal lateral line root, as already described, has
a discrete ganglion, and a reference to the chart will show
that the communis, ventral lateral line and motor roots
enter the ganglionic mass above by two nerve bundles.
The anterior one is the communis root and the posterior
represents the ventral lateral line and motor roots fused
together, the motor fibres of course having no connection
with the ganglion cells. The entry of the trigeminus root
into the Gasserian ganglion is described above.
Leaving the compound ganglionic mass are three
large nerve trunks: (1) the Truncus supraorbitalis; (2)
the Truncus infraorbitalis; and (38) the Truncus hyo-
mandibularis—all compound trunks into which both
trigeminal and facial nerves enter. It will be seen on
reference to the chart that the last is formed by three
nerve bundles from the ganglionic mass uniting together.
The most anterior of these arises from the Gasserian
ganglion and thus forms the trigeminal cutaneous Vil.
component of the hyomandibular trunk. In Menzdia the
cutaneous vil. is extracranial, and is formed by two
bundles from the Gasserian ganglion fusing together. In
the Plaice there are one large and two very small bundles
—all intracranial. The middle of the three nerve bundles
above is the communis root, and the posterior the fused
ventral lateral line and motor roots. The motor vii., as
mentioned above, joins the ventral lateral line root proxi-
mal to the ganglionic mass. At first they remain distinct,
the motor vil. lying on the outer face of the ventral lateral
line ganglion. Before leaving the ganglion, however, the
two roots become almost too intermingled to be
distinguished.
Before proceeding to describe the divisions of the vth
SEA-FISHERIES LABORATORY. 269
and viith nerves, it may be mentioned that the Gasserian
ganglion is the only one to receive a prominent R. com-
municans from the sympathetic. There also arises from
the same ganglion a motor nerve which has traversed the
ganglion and passes to the M. depressor operculi
(m. d. op.). This is the most posterior nerve passing
through the trigemino-facial foramen.
The trigemino-facial foramen (represented by a ring
in the chart) transmits the trigeminal nerve + the dorsal
lateral line root of the facial + a communis vii. com-
ponent. The jugular foramen (the posterior ring in the
chart) transmits the hyomandibular trunk, comprising the
remainder and greater part of the facial + a cutaneous
component from the trigeminus.
The various nerve rami may now be described under
the names of the nerves to which they belong. |
Nervus Trigeminus—yv.
1. Nervus ophthalmicus profundus (fig. 26, 0. pr.).—
The root of this nerve (Radix ophthalmici profundi) arises
on the right side from the root of the trigeminus near the
brain, and proximal to the Gasserian ganglion. It passes
downwards and forwards over the inner face of the latter
ganglion between it and the brain, and enters the pro-
fundus ganglion, which, though closely opposed to the
inner face of the Gasserian, is absolutely distinct from it.
From the profundus ganglion an apparently single nerve
arises which leaves the skull cavity with the rest of the
vth and becomes intimately attached to the sympathetic.
We could not be certain whether a few fibres were not
given off to accompany the R. ophthalmicus superficialis
y., thus constituting a Portio ophthalmici profundi. The
nerve from the profundus ganglion passed with the sym-
pathetic through the skull wall again by a special small
270 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
foramen into the eye muscle canal. The two bundles
separate in front, but for a time the union is so close that
they could not be satisfactorily analysed. However, most
of the profundus fibres proximal to the ciliary ganglion
separate out as the Ramus ciliaris longus (cdl. l.), but a
few of them accompany the sympathetic to the ciliary
ganglion (cil. g.) as its Radix longa (re. U.). The R.
ciliaris longus leaves the eye muscle canal in front and
accompanies the right rectus superior muscle to the eye,
which it enters from above. <A true Ramus ophthalmicus
profundus is therefore absent in the Plaice.
On the left side the profundus nerve only separates
from the root of the trigeminus just before the latter
reaches the Gasserian ganglion. The only other differ-
ences between the two sides are in matters of detail
(ep. the description of the sympathetic).
The only other Teleost which is said to possess a
separate profundus nerve and ganglion is Z7rzgla, in
which, according to Stannius, it is in exactly the same
condition as in the Plaice, except that it leaves the skull
cavity by a special foramen. A vestigial profundus nerve
is also described by Herrick in Menidia. Its occurrence
in the Plaice in the form described above is therefore of
exceptional interest. Stannius missed it altogether in the
Plaice, and hence his statement that the v.-vu. complexes
of Trigla and Pleuronectes only differ in this respect 1s
inaccurate. :
2. Ramus ophthalmicus superficialis (7. oph. sup. v.).
—Arises from the narrowed anterior extremity of the
Gasserian ganglion, and constitutes the trigeminal portion
of the Truncus supraorbitalis. It accompanies the nerve
of the same name from the facial for a considerable dis-
tance, being at different places more or less intermingled
with it. In front, however, it separates from the facial
SEA-FISHERIES LABORATORY. DE:
and is seen as a slender nerve passing forwards over the
eye and somewhat near the skin, which it supplies with
general cutaneous fibres. It is not free from lateral line
fibres, as shown by the little plexus innervating sense
organs 3 to 5 of the supraorbital canal.
The Truncus infraorbitalis (¢. wf.), consisting of the
T. maxillo-mandibularis + lateral line and communis
eomponents from the facial, arises ventrally from the
Gasserian ganglion and passes sharply downwards and
forwards. It soon splits into two large nerves as follows:
3. R.maxillaris superior (or R. maxillaris—mz. v.).—
Closely accompanied by a lateral line component from the
facial, which will be described in its proper place. It
consists largely of general cutaneous fibres, and possibly
also transmits some communis vil. fibres. It passes
straight forwards across the orbit on to the upper jaw,
and gives off a cutaneous twig in front, accompanying the
lateral line component, and is finally distributed mostly
to the skin of the anterior part of the face.
4. R. maxillaris inferior (or R. mandibularis—
man. v.)—May also contain a communis component.
Divides at once into a smaller upper and a larger lower
branch. Both give off some purely motor branches, and
the nerve is thereafter continued obliquely downwards
and forwards across the orbit in two sections—a smaller
upper and a larger lower. The former contains a few
motor fibres, the latter more of the same, the remaining
fibres being of small calibre and staining very faintly.
The upper one bifurcates, each half containing both the
sensory and motor fibres, and terminates in the posterior
region of the orbit. The lower one passes forwards,
following the ventral curve of the orbit, and giving off
several branches on the way, on to the lower jaw, on which
itends. At about the anterior region of the orbit it gives
272 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
off a branch below which follows the R. mandibularis
externus vil. for a bit, but ultimately separates out again.
Some of the fibres of the R. mandibularis are distributed
to the mucous surface, and hence probably represent a
communis vil. component.
Rami 2, 3 and 4 are known as the first, second aud
third divisions of the trigeminus, and hence its name.
The profundus nerve, though associated with the
trigeminus, may be a separate nerve altogether, and its
relations with the fifth purely secondary.
Nervus Facialis—vlIl.
The dorsal lateral line root splits to form the first
five of the following branches :—
1. R. lateralis recurrens facialis (/. rec. va.).—This
is the first branch to arise from the root, and is given off
intracranially from the top of the ganglion. It soon gives
off two twigs behind as shown in the chart, each of which
enters the skull wall by a separate aperture. They unite
in the skull wall, however, and after leaving it, pass back-
wards to reinforce the posterior division of the R. oticus.
The main trunk passes upwards and forwards between the
optic lobe and the skull wall, perforates the frontal at the
place marked with a ring in the chart, and is distributed
to pit organs along its course. ‘The R. lateralis acces-
sorius (=R. lateralis trigemini) is, as pointed out by
Stannius, absent in the Plaice, but the present nerve
undoubtedly corresponds to the lateral line fibres which |
accompany it in the Cod, as described by Herrick. There
are a very few fine fibres in it, which may conceivably be
a vestigial R. lateralis accessorius, but the bulk of its fibres
certainly belong to the lateral line series.
A little distal to the origin of the above, and also
intracranially from the top of the ganglion, at the place
SEA-FISHERIES LABORATORY. ie
indicated by a spot in the chart, the second branch arises.
This is the R. buccalis. It at once splits into a dorsal and
a ventral division. The former itself divides as it passes
through the skull wall above the trigemino-facial foramen
into a posterior R. oticus and an anterior R. buccalis
externus. The latter is the R. buccalis internus, and
leaves the cranial cavity by the trigemino-facial foramen.
2. R. oticus (r. of.).—Passes almost straight upwards
and splits into two, one passing straight forwards and the
other, except for the curious bend at its termination,
straight backwards. ‘The former supplies sense organ 13
of the infraorbital canal, the latter, after being reinforced
as above described, sense organs 14 and 15 (the last two).
3. R. buccalis externus (out. buc.).—Passes down-
wards and forwards, gives off a twig to sense organ 12 of
the infraorbital canal, and then courses as shown in the
chart to supply sense organs 7 to 11 of the same canal.
The first 7 sense organs of this canal were not enclosed at
the stage at which the sections were cut, and were hence
lying freely on the surface. The first three are supplied
by the R. buccalis internus, but no nerves could be traced
to the fourth, fifth and sixth sense organs. This is due to
the fact that the outer buccal nerve, after supplying sense
organ 7, becomes extremely thin, and as it coursed among
the numerous pigment cells on this, the ocular, side, could
not be traced. It is most probable, however, that it sup-
plied sense organs 4, 5 and 6. Comparison with the
eyeless side, where there is no pigment, does not help, as
the canal is shorter and develops more quickly.
4. R. buccalis internus (in. buc.).—Leaves the skull
cavity by the trigemino-facial foramen and accompanies
the superior maxillary nerve. In front, opposite the
infraorbital canal it divides into an upper inner buccal
(up. in. buc.) and a lower inner buccal (low. en. buc.). The
W
274 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
former accompanies the superior maxillary nerve, receives
a bundle of fibres from it as in Menidia, and ultimately
supplies pit organs in the region of the nose, as in Menidia
and Gadus, and also the supposed vestige of the left
supraorbital canal with its single sense organ (sup. c.”).
The latter after a very long course, during which it gave
off no branches at all, was ultimately traced to sense
organs 1, 2, 3 of the infraorbital canal.
0. After giving off the R. buccalis the main trunk
of the dorsal lateral line root is continued forwards as the
R. ophthalmicus superficialis facialis, forming the
remainder of the T. supraorbitalis (r. oph. sup. viz), and
which is closely associated with the nerve of the same
name from the trigeminus. It is connected at its origin
with the Gasserian ganglion, situated below it. Its course
and relations will be seen on reference to the chart, and it
is mostly concerned with supplying the 5 sense organs of
the supraorbital canal.
6. Ramus palatinus facialis (pal.).—Arises intra-
cranially from the geniculate ganglion proximal to the
formation of the Truncus hyomandibularis. It remains
within the skull until it reaches the region of the orbit.
At first it passes forwards and downwards, very closely
attached to the cranial sympathetic from section 536 to
494, and ganglion cells really belonging to the latter have
been described as belonging to the palatinus. Subse-
quently the palatinus passes downwards, and enters the
eye muscle canal. It leaves this canal in front and passes
far in front of the brain straight across the orbit and
above the superior maxillary v. nerve. In the anterior
region of the orbit, where it lies over the roof of the
pharynx, it turns sharply downwards. During its course
across the orbit it gives off branches to the terminal buds
in the roof of the pharynx.
SEA-FISHERIES LABORATORY. PTS
The Truncus hyomandibularis (¢. 4m.) is formed by
the union of three nerve bundles as described above. It
contains the following four components as in Menzdia, but
the second is absent in Gadus :—
1. Cutaneous - - - Ne:
2. Communis
3. Lateral line ventral root | VII.
4. Motor
Just as the Truncus leaves the jugular foramen it
gives off a communis nerve which we have identified as
the
7. Post-trematicus vii. (Yost. viz.)—This nerve after
a short course through 10 sections fuses with the very
large communis nerve from the glossopharyngeus known
as Jacobson’s anastomosis (Jac. anast.).* The post-
trematicus vii. arises considerably ventral to and quite
separately from the palatinus vil. Judging from its blood
vessels and innervation we regard the pseudobranch of the
Plaice as a single hyovdean demibranch, but whether
anterior or posterior we have not been able to determine.
In this we differ from Herrick,t who regards the pseudo-
branch of Menidza as a mandibular demibranch, and hence
our post-trematicus vii = his pre-trematicus vil. We
have, however, no space for a discussion of this question,
and further it may be, as Herrick suggests, that the
pseudobranch is not homologous throughout the Teleostean
series. One of us has formerly maintained that Jacob-
son’s anastomosis is really the palatinus (pharyngeus) 1x.
*The post-trematicus arises from the hyomandibular trunk directly
the latter issues from the jugular foramen. Stannius found it in the
Plaice, and regards it as a sympathetic nerve, but this of course is an
error, as the sympathetic is otherwise accounted for.
t Herrick also states that Jacobson’s anastomosis of Gadus passes from
vii. toix. It is really of course the other way about, as we state above.
See a more recent paper by Herrick (Jour. Comp. Neurol. xi., p. 194).
276 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
‘his it undoubtedly is in many Teleosts, but in the Plaice
it seems to correspond to palatinus and pre-trematicus ix.
tused together. Otherwise there is no pre-trematicus ix.
in the Plaice at all, or the whole of Jacobson’s anastomosis
is that nerve, which is somewhat unlikely.
The result, therefore, of the fusion of these two nerves
is a large bundle formed in greater part of communis 1x.,
but also to a lesser extent of communis vii. And as these
two components consist of exactly similar fibres, the final
course of each component can only be traced by degenera-
tion experiments. The combined nerve (com. vw. + 22.)
passes almost straight downwards on the inner side of the
large pseudobranch and divides into an anterior branch to
the mucosa of the roof and upper lateral wall of the
pharynx, and a posterior branch to the mucosa of the
ventro-lateral wall of the same. Although several of these
branches passed close to the pseudobranch, none could be
traced into it, as, Herrick also finds in Menidia. But the
nerve fibres are of very fine calibre and difficult to follow,
and as the pseudobranch has no other nerve supply it
must derive its innervation from this source, and indeed
dissection shows that it does do so. But whether its fibres
come from communis ix. or vii., or both, must be subse-
anuently determined. The large and _ well-developed
pseudobranch, however, may well explain the size of
Jacobson’s anastomosis.
Near the origin of the post-trematicus some motor
branches are given off from the Truncus hyomandibularis
as in Menizdia and Gadus. The truncus then passes out-
wards and downwards, and enters a canal in the hyoman-
dibular bone, as in Gadus. Soon afterwards it gives off
behind a lateral line nerve known as the :—
8. Ramus opercularis superficialis vii. (07. s. v2.) —
This at once gives off two twigs which supply the last two
SEA-FISHERIES LABORATORY. 277
sense organs (10 and 11) of the hyomandibular canal, and
is then continued at first backwards and then sharply
downwards towards the edge of the operculum, to supply
the opercular line of pit organs.
Below and before it bends forwards the Truncus
hyomandibularis splits into two large nerves—(1) an upper
one turning forwards, the R. mandibularis vil. (man. vit.),
consisting of two components accompanying each other, a
coarse fibred R. mandibularis externus vil. (man. ext. vid.)
and a fine fibred R. mandibularis internus vil. (man. int.
vu.), and (2) a R. hyoideus vii. (r. Ay.) passing straight
downwards.
9. R. hyoideus (r. hy.)—Consists of two components,
a coarse motor and a fine-fibred general cutaneous—just as
in Menidia, but differing from Gadus. As in Menidia
the hyoideus below divides into anterior and posterior
branches. Sense organ 9 of the hyomandibular canal is
suppled from the hyoideus, but this bundle of lateral line
fibres has previously been handed over to it from the
external mandibular.
As the R. mandibularis passes forwards it gives: off
branches to pit organs, especially one long branch above
corresponding to Herrick’s nerve m. vw. 5. It may be
mentioned that the two components forming the R. man-
dibularis are each easily followed by the microscope.
Below a large lateral line branch is given off which sup-
plies sense organs 6, 7 and 8 of the hyomandibular canal.
In front, the two components separate out, and thereafter
pursue independent courses.
10. R. mandibularis internus (man. int. vi.).—A
communis nerve, situated much below the externus.
Passes sharply inwards to the visceral surface, and does not
rejoin the externus again as in Menidia, and as is usual in
Teleosts, with the exception of Cottus according to Stannius.
278 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
11. R. mandibularis externus (man. ext. vii.)—A
coarse-fibred lateral line nerve, but contains some fine
fibres. In front is joined by a fine-fibred nerve from the
R. mandibularis v., but this soon separates out again.
Just opposite sense organ 3, the external mandibular
perforates the dentary and thereafter lies over the roof of
the hyomandibular canal. The anterior free portion of
the external mandibular supplies the first 5 sense organs
of the hyomandibular canal.
We may now refer very briefly to the statements of
Stannius on the trigeminal and facial nerves of the Plaice.
His analysis of the roots of these two nerves is given in
great detail (pp. 23-25), and is remarkably accurate con-
sidering the methods at his disposal. His five roots cor-
respond with ours as follows :—
First Root = our first or trigeminal root (cutaneous +
motor)
Second ,, = the dorsal lateral line root of our
Third) 4. =the -venthal.s.: 2 ; second
Fourth ,, =the communis root eee:
Fifth ,, =our third or the motor vii. root.
His statement that branches of the superior maxillary
anastomose with the palatinus vil., and are distributed to
the mucous membrane of the mouth, points to a communis
component in the former nerve. He describes our nerve
called the R. lateralis recurrens vii., but his statement
that the R. palatinus vii. has a discrete opening in the
skull is of course an error.
Nervus Acusticus—VIIl. (Fig. 24.)
The ear is described with the other sense organs.
All the fibres of the auditory nerve (viil.) arise from
the same region of the brain (tuberculum acusticum) as
the lateral line fibres. The two sets of fibres form a very
SEA-FISHERIES LABORATORY. 279
large complex in the brain easily recognisable by the large
size of the fibres, and the density with which they stain.
There can hardly be said to be a single root to the
acusticus, its fibres becoming associated into at least two
rami just before or on leaving the medulla. As in
Menidia the very minute ganglion cells are not found on
the acusticus until it breaks up into its ramuli. In front, as
above described, the auditory nerve leaves the medulla in
conjunction with the motor vii., and is confused with it.
Its division into an anterior Ramus vestibularis and a
posterior R. cochlearis is not so obvious as in other fishes, ~
on account of the manner in which 1t emerges from the
medulla. Its further divisions or ramuli are therefore
now described.
1. R. acusticus ampulle anterioris (r. a. a.).—Most
anterior branch, and courses forwards.wedged in between
the motor vil. and the utriculus. It then passes upwards
and outwards to the outer wall of the ampulla, the sense
organ of which it enters from the front.
2. R. acusticus recessus utriculi (r. r. u.)—Some-
what diagrammatic in the figure, as it really passes back-.
wards to the floor of the utriculus to reach its sense organ.
3. R.acusticus ampulle externe (7. a. ¢.).—Passes
almost straight outwards underneath the floor of the
‘utriculus towards the outer wall of the external ampulla
direct to its sense organ.
4. R. acusticus sacculi (7. sac.)-—Courses at first
straight downwards at right-angles to the preceding
ramulus, and then backwards and downwards internal to
the sacculus to reach its sense organ. As it passes back-
wards it was connected with a small nerve bundle, the
nature of which was not determined.
The nerve extending backwards to supply the two
posterior sense organs of the ear is separated off from the
280 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
auditory nerve very early, and indeed almost arises sepa-
rately from the brain. It gives off a nerve above, which
is the
5. R. acusticus ampulle posterioris (7. a. p.).—Is at
first opposed to the external surface of the glosso-
pharyngeus, and lies between it and the utriculus, but
exchanges no fibres with it. It turns upwards, crosses the
glossopharyngeus iust as the latter is bending downwards,
and becomes attached to the outer face of the lateralis,
but again does not mingle with it. Still coursing
upwards it crosses the lateralis, curves outwards over the
top of the posterior ampulla behind, and, now lying
externally to the ampulla, bends forwards to reach its
sense organ. |
The remainder of the posterior nerve is the
6. R. acusticus lagene (r. /.)—Passes backwards
over the roof of the sacculus, gives off a bundle to that
part of its sense organ situated there, and then crosses
inwards and downwards to supply that part of the sense
organ situated on the inner wall of the sacculus near the roof.
The Ramulus acusticus neglectus, with its sense
organ, is absent in the Plaice. In other fishes the Ramus
vestibularis, or anterior root=ramuli 1, 2 and 3, whilst
the Ramus cochlearis, or posterior root=4, 5 and 6+the
R. acust. neglectus.
Nervus Glossopharyngeus—lX.
Contrary to the condition found in Gadus and Menedia
the glossopharyngeus leaves the medulla by only one root.
This, however, consists of two large bundles, which, on
being traced into the brain are seen to belong to the
motor and communis systems. There are no cutaneous
fibres in the glossopharyngeus. In the two fishes above,
the motor fibres leave the brain by a separate root.
SEA-FISHERIES LABORATORY. 281
The single root of the ixth (r. zx.) leaves the medulla
much below and somewhat behind the root of the lateralis.
It is situated quite by itself, and distinct from any other
root. It passes almost straight backwards above and
slightly to the inner side of the posterior division of the
acusticus, and becomes related to the R. acust. ampulle
posterioris as above described. It then courses almost
straight outwards and downwards, first between the
sacculus and utriculus, and afterwards between the
sacculus and the skull. It now bends forwards and down-
wards, passes through its foramen (represented by a ring
in the chart), and enters the large ganglion (g. 2a.) lying
just outside the skull.
Before entering the ganglion, and just after leaving
the foramen, the root gives off above a motor branch.
This passes forwards over the top of the ganglion, and
enters the R. post-trematicus, thus accounting for most
of the motor fibres of the glossopharyngeus.
The peculiar course of the root first backwards and
then forwards is due to the position of the ear. ‘That is
to say it passes straight backwards until it can escape
outwards through the fissure between the sacculus and the
utriculus behind.
The nerve arising from the ganglion is very flattened
and ribbon-like, and soon splits into two large nerves—an
upper R. post-trematicus and a lower Jacobson’s
anastomosis (Jac. anast.). ‘The latter passes forwards,
gives off a motor branch below, the fibres of which have
previously traversed the ganglion to reach it, and finally
anastomoses with the post-trematicus vii., which see for
its subsequent course. The relations of the sympathetic
to the glossopharyngeus are described with the former
system.
R. post-trematicus (post. wx.)—Courses forwards
282, TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
above Jacobson’s anastomosis, then bends sharply down,
crossing the latter externally, and passes backwards and
downwards until it reaches the first branchial arch, where
it divides into two almost equal branches. One now
passes straight downwards on to the anterior or concave
aspect of the arch. ‘This is the uppermost and smaller of
the two, and may be called, like the similar divisions of
the RR. post-trematici of the vagus, the R. post-trematicus
dorsalis (text-fig. 4). It courses forwards in this position
giving off branches until it became too inconspicuous to
be followed, which happened before the arch joined the
first and second basibranchials. The other division (R.
post-trematicus ventralis), the lower and larger of the two,
after continuing backwards for a bit, bent downwards and
forwards to reach the posterior or convex aspect of the
arch, curving externally round the elbow formed by the
junction of the epi- and cerato-branchials. It then follows
the arch forwards in the same position, gives off a branch
above, and ultimately reaches the junction of the first
branchial arch with the basi-branchials. Thereafter it
arrives at the lateral edge of the branchial isthmus, cross-
ing forwards under the hypobranchial. In front of the
latter, it turns sharply upwards, and reaches the dorsal
surface of the isthmus near the lateral edge, and lying
just under the mucous membrane at the side of and above
the first basi-branchial. Just over the cerato-hyal it
anastomoses with the first branchial division of the vagus.
It is now on the tongue, and tapers down and is lost under
the mucous membrane of its dorsal surface, thus reaching
much further forwards than the dorsal division.
We now proceed to describe the vagus complex, and
we find that this is formed by the Ramus lateralis vagi,
belonging to the lateral line system, and having only a
ee Rae ene 8
>
ee
ote
SEA-FISHERIES LABORATORY. 283
secondary and unimportant connection with the vagus,
and the N. vagus sensu stricto. There are no intracranial
branches from the vagus - complex, as_ stated by
Stannius.
R. lateralis vagi (r. lat. x.).—Arises from the tuber-
culum acusticum, like the auditory nerve and other lateral
line nerves, but appreciably below the exit of the latter
and considerably above and somewhat in front of the root
of the glossopharyngeus. It also arises considerably in
front of the roots of the true vagus. The root (7. lat. x.+)
passes downwards and backwards, lying immediately
external to that of the vagus proper, and for a time
between it and the posterior division of the acusticus, as
above described. It has, however, no connection with
either, and passes out of the same foramen (indicated by
a ring in the chart) as the rest of the vagus, but external
to the latter. As in Menidza the lateralis consists mostly
of the large strongly myelinated nerve fibres, but also has
many smaller ones.
Immediately on leaving the skull the lateralis gives
off the R. supratemporalis vagi (7. st. w.), at the base of
which is a small ganglion distinct from the main lateralis
ganglion. The supratemporal branch, as shown in the
chart, is distributed on the ocular side to the 4 sense
organs so far developed in the supratemporal portion of
the lateral canal, and also to the first two sense organs in
the main portion of the same, 2z.e., sense organs 1 to 6.
After giving off this branch the lateralis expands into the
lateralis ganglion (/. g. w.). The nerve arising from the
ganglion passes upwards, and divides, as in the Cod, into
the R. lateralis superficialis vagi (7. lat. swp. x.), coursing
just under the skin in the neighbourhood of the main
portion of the lateral canal the sense organs of the anterior
half of which it supplies, and the R. lateralis profundus
284 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
vagi* (r. lat. prof. #.), coursing below the above, and
between the dorsal and lateral musculature, far from the
surface. The latter gives off no branches until it passes
upwards and outwards to supply the sense organs of the
posterior half of the main portion of the lateral canal. It
is at intervals very closely connected with branches from
spinal nerves, but no fibres are exchanged as far as we
could see. The superficialis division, besides supplying
its portion of the lateral canal, gives off in front and above,
in fact as its first branch, the R. lateralis recurrens vagi
(2. rec. #.). This is also a true lateral line nerve distri-
buted to pit organs, and must therefore not be confounded
with the R. lateralis accessorius (trigemini), although in
some fishes its homologue appears to accompany the latter.
Its course, which is very extensive and just under the skin,
is shown in the chart, and it corresponds precisely to the
similar branch arising from the facial, and called the R.
lateralis recurrens facialis (/. ree. viz.).
Nervus Vagus—x.
Arises by a single large root, which is, however,
formed by several large bundles (Stannius says 5) uniting
just on the surface of the medulla, and which is further
reinforced by two very small bundles in front, as shown
in the chart. This root (r. x.) is quite distinct both from
the roots of the glossopharyngeus and lateralis,t and in
fact the roots of these three nerves are more distinct and
clear in the Plaice than in most Teleosts. The vagus root
* These nerves must not be confused with the R. lateralis trigemini of
the Cod (cp. Parker’s ‘‘ Zootomy’’), which is not represented in the Plaice
at all. The latter is a communis nerve supplying its own, and not
lateral, sense organs. It has no connection typically with the trigeminal
nerve, and should be called the R. lateralis accessorius.
+Stannius states that fibres pass from this root to the root of the
lateralis in the Plaice, but this is not the case.
SEA-FISHERIES LABORATORY. 285
consists very largely of communis fibres from the Lobus
vagi, but also contains motor and cutaneous components.
In its intracranial course it is almost entirely covered by
the root of the lateralis, and before it reaches its foramen
in the skull, and whilst passing through it proximally, it
bears a smallish ganglion distinctly separated from the
other vagus ganglia. This is the jugular ganglion (Jug. g.),
also found by Herrick in Gadus and Menidia. It is the
ganglion of the cutaneous fibres of the vagus, and forms
typically the R. cutaneus dorsalis vagi, and the R. oper-
cularis vagi.
R. opercularis vagi (r. op. «.)—This is given off
directly the vagus leaves the skull, and at its origin is
very closely opposed to the base of the R. supratemporalis
vagi (see chart), but it does not fuse peripherally with it,
as in Gadus according to Herrick. It passes forwards,
and divides into antero-dorsal and postero-ventral branches
supplying the skin of the opercular and supra-opercular
regions. It contains both hght and heavily myelinated
fibres. After giving off this ramus, the vagus swells into
the large ganglionic complex (g. #. 2-5), of which only the
first ganglion (g. w. 1) is completely distinct.
1.—Truncus branchialis primus Vagi (¢. «. 1).
Arises from the dorsal aspect of the vagus on
its inner surface. It passes inwards and backwards
towards the first spinal sympathetic ganglion, to which
it becomes closely opposed. It then bends forwards
and downwards, and at once swells into its large
ganglion (g. #. 1), which is quite distinct from the other
vagus ganglia, as is general among Teleosts. ‘lhe motor
component of the truncus passes over the external surface
of the ganglion. Distal to the latter the truncus passes
downwards and forwards and divides into an upper pre-
286 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
trematic + pharyngeal branch, and a lower R. post-
trematicus. ‘The former passes forwards, and divides imto
two rami, both of which at once turn downwards and back-
wards. ‘These are the R. pharyngeus (ph. x. 1) and the R.
pre-trematicus (pre. 1). The pharyngeus courses down-
wards and immediately breaks up in the mucous mem-
brane of the roof of the mouth. The pre-trematicus
reaches the first branchial arch, lying just internal to the
undivided post-trematicus ix. When the latter divides it
thereafter accompanies the ventral division of it, but
curves round the inner aspect of the elbow formed by the
epi- and cerato-branchials.
The R. post-trematicus (vost. 1.) gives off below just
at its origin a motor branch, and shortly afterwards curves
downwards, outwards and backwards to reach the second
branchial arch. There it divides into two branches, just
as in the ixth, and these bend externally round the epi-
and cerato-branchial elbow, one lying above the cerato-
branchial and the other below it. Thereafter their course
resembles that of the post-trematicus 1x.
2.—T. branchialis secundus Vagi (¢. a. 2).
The ganglion of this division is more or less massed
with the remaining vagus ganglia (g. #. 2-5), and their
boundaries are difficult to determine. The truncus arises
from the internal surface of the ganglionic mass, like the
first. A small mixed plexus of communis and motor
fibres, not shown in the chart, may be described here. It
arises by 3 roots—one from the second branchial ganglion,
and two from the third. These three roots form a plexus
from: which 3 nerves arise, two of which pass forwards and
inwards and break up in the roof of the pharynx, whilst
the third also passes forwards as a purely motor
nerve,
SEA-FISHERIES LABORATORY. 287
The truncus now courses downwards and forwards,
and almost at once divides into an upper palatine + pre-
trematic branch and a lower R. post-trematicus (post. 2).
The former gives off 3 RR. pharyngei (ph. w. 2) to the roof
of the mouth, and is then continued downwards on to the
second branchial arch as the R. pre-trematicus (pre. 2).
The latter, as it passes forwards, gives off from its upper
border two motor twigs not shown in the chart, and finally
breaks up as usual into two branches, which pass on to the
third branchial arch, and the distribution of which is
essentially the same as the corresponding divisions of the
first branchial trunk.
3.—T’. branchialis tertius Vagi (¢. «. 3).
Arises from the ventral edge of the compound
ganglionic mass. ‘The two nerves it contributes to the
pharyngeal plexus have been described above. Another
nerve not shown on the chart arises posteriorly and
internally from the base of the truncus. It passes sharply
downwards and backwards to the roof of the pharynx.
The truncus itself, directly it leaves the ganglion, divides
into a palatine+pre-trematic branch coursing gradually
downwards and forwards, and a R. post-trematicus, pass-
ing sharply downwards and backwards. ‘The former
divides as usual into a R. pharyngeus (ph. w. 3) and a R.
pre-trematicus (pre. 5), the latter passing on to the third
branchial arch. The R. post-trematicus (post. 3) breaks up
into the usual two branches much sooner than usual,.as in
Mendia. The anterior one gives off at once in front a
motor branch. Both pass on to the fourth branchial arch
and are distributed as usual.
The T. branchialis quartus vagi is so closely asso-
ciated with the remainder of the vagus that it cannot be
288 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
separately described. After giving off the branchialis
tertius, the vagus passes backwards and splits into two
large nerves. The upper one is the R. intestinalis vagi
(r. intest. 2.), and the lower one contains the fourth
branchial trunk, together with the RR. cardiacus et
cesophageus vagi. The upper division gives off two
branches, which join the rich csophageal plexus formed
by branches of the lower division, and afterwards passes
almost straight backwards as the R. intestinalis, wedged
in at first between the kidney, thymus and roof of the
cesophagus. It gives off branches to the esophagus from
time to time, and passes downwards until it hes at the side
of the latter structure. It ultimately splits into two, both
of which break up in the lateral wall of the-csophagus
and are lost before the stomach is reached.
The lower division, before and after it separates from
the R. intestinalis, gives off about 10 mostly motor nerves,
which at once form an elaborate plexus in the region of
the dorso-lateral wall of the cesophagus. These nerves
and others are not shown in the chart. It then passes
shghtly downwards and backwards, and gives off in front
the fourth R. pre-trematicus (pre. 4), which passes sharply
downwards and forwards. This at once gives off in front
a small motor twig, and then courses straight on to the
fourth branchial arch. It was not observed to give off a
R. pharyngeus unless an extremely small twig distributed
apparently to the side wall of the pharynx represented
that branch.
After giving off the fourth pre-trematicus, the lower
division turns almost straight downwards, and then
divides into four branches. ‘Two of these pass forwards
at once into the ventral wall of the cesophagus, and repre-
sent the final derivatives of the R. esophageus. The third
accompanies the inferior pharyngeal bone, and is therefore
SEA-FISHERIES LABORATORY. 289
the fourth R. post-trematicus (post. 4).* The last branch
continues the downward course, gives off a motor branch
behind, and then courses forwards and downwards in close
contact with the roof of the pericardium. This may be
the R. cardiacus (r. car: ?), but it does not actually pass on
to the sinus venosus, and certainly contains a number of
motor fibres distributed outside the heart. The true R.
cardiacus may therefore have been overlooked, especially
as Stannius proved by stimulation experiments that the
vagus of the Plaice sent fibres to the heart.
3.—THE Spinat Nerves (Fig. 27).
ae- Fourth Spinal Nerve.
We describe this spinal nerve first since in most
respects it may be taken to represent the structure of most
of the other spinal nerves. The visceral fibres are not
taken into account.
The fourth spinal nerve arises by two roots—a dorsal
largely sensory (d. 4) and a ventral motor (v. 4). Each
root leaves the neural arch of the third vertebra by a
separate foramen, as described by Stannius, and passes at
once into a single large extra-vertebral ganglion (g. 4).
The motor fibres for the R. medius and R. ventralis per-
forate the ganglion, but those for the R. spinosus pass
upwards internal to it. One lateral, one ventral and two
dorsal branches arise from the nerve. ‘he two last are
the R. communicans (sensory) and the R. spinosus (motor),
whilst the former are respectively the R. medius (sensory
and motor) and the R. ventralis (sensory and motor).
1. R.communicans (r. com. 4).—This sensory ramus
* We differ from Herrick in naming two of the branches of the vagus.
His fourth post-trematic (fig, 4, post 4) is apparently the pharyngeus iv.,
and his ‘‘ branches of the vagus for the inferior pharyngeal teeth ’’ (ph. v.,
same figure) are equivalent to our post-trematic iy,
xX
290 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
arises from the antero-dorsal region of the ganglion,
passes upwards, and fuses with the R. spinosus of the
nerve in front (third spinal).
2. R. spinosus (7. sp. 4)—A motor ramus leaving
the postero-dorsal region of the ganglion, and giving off
near its base a posterior lateral branch for the inter-
mediate portion of the dorsal musculature. It then
passes dorsally, and fuses with the R. communicans of the
nerve behind (fifth spinal). The resulting mixed trunk
continues upwards and forwards in the dorsal musculature
very close to the middle line, and is distributed to the
dorsal portion of the dorsal musculature, the inter-spinal
muscles and the dorsal skin.
3. R. medius (r. m. 4)—This mixed ramus, leaving
the ventral extremity of the ganglion, courses laterally
outwards through the ventral portion of the dorsal muscu-
lature, and bifurcates. The upper division accompanies
the intermuscular bone, and supples the ventral portion
of the dorsal musculature. The lower division passes
downwards into the lateral musculature (which it sup-
plies), obliquely crossing under the R. lateralis profundus
vagi (fig. 23, r. lat. prof. x.), to which it may be very
closely attached, but with which it never mingles. The
sensory fibres of the ramus pass out laterally to the skin,
and supply that portion of it around the lateral sensory
canal. ,
4. R. ventralis (vr. v. 4).—This mixed ramus also
arises from the ventral extremity of the ganglion, and is
the largest of all. It passes downwards, and just over the
kidney receives the R. communicans from the fourth
spinal sympathetic ganglion (com. wv.). It then turns out-
wards between the lateral musculature and the kidney,
and afterwards downwards again between the lateral
musculature and the liver. Finally it continues down-
SEA-FISHERIES LABORATORY. 291
wards on the inner surface of the abdominal wall, and just
under the peritoneum. This ramus supplies the ventral
musculature and ventral skin. In the region of the
appendages the limb girdles and fins are supplied from
R.R. ventrales. In the specimen now investigated, how-
ever, the fourth spinal was not connected with either the
pectoral or pelvic appendage. ‘The fourth R. ventralis
anastomoses below with the nerve 7. v. 2+38!1, as described
below.
The First Spinal Nerve.
This nerve is a compound of at least two spinal nerves,
‘since it has two ganglia and most of its principal rami
are in duplicate. It is, however, here described as the
first spinal, on account of the difficulty of completely
isolating its constituents.
The ganglia and roots of the first spinal are situated
in the bony tube formed by the exoccipital, and leading
from the foramen magnum into the cranial cavity proper
(see fig. 4). There is one main foramen for the nerve,
which tunnels transversely the narrowed base of the par-
occipital condyle, as shown in fig. 3 (above the lower letters
Ee. O.). Another smaller foramen for the R. spinosus b.
is situated immediately above this, and occasionally there
is another larger one immediately below it for the R.
ventralis, as shown in the chart. Usually, however, the
latter nerve passes through the main foramen. There are
thus at least two foramina for the first spinal nerve, and
there may be three—all situated in the exoccipital.
The first spinal has two perfectly distinct ganglia—
an intracranial ganglion (g. ztcr.), and an extracranial
ganglion (g. eatcr.). These two ganglia are connected by
a large bundle of sensory and motor fibres which pass
through the main foramen (indicated in the chart by the
292 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
oval dotted area). There was in the specimen sectioned
a discrete patch of cells on the right side on the R.
ventralis also, but in other examples these were con-
tinuous with and part of the extracranial ganglion.
We follow Fiirbringer and Herrick in designating
the cephalic constituent of the first spinal by the letter d,
and the caudal constituent by the letter ¢. It will be
observed that the Plaice has three ventral roots instead of
the two described by Herrick in Menedia,* and of these
the extra one is undoubtedly the first (v. 6.*).
The first spinal nerve of the Plaice has two dorsal
sensory (mostly) and three ventral motor roots. Of the .
two dorsal roots the first (d. 0.) is larger than the second
(d. c.), and arises obviously from the spinal vth tract.
They both pass into the intracranial ganglion. Of the
three ventral roots, the first (v. 6.1) is very long and
slender, and fuses with the second (v. b.). The third (v. ¢.)
is very short, and is the largest of all the roots. All three
ventral roots pass into the intracranial ganglion. |
The following nerves arise from the intracranial
ganglion :— ;
1. R. spinosus, b (7. sy. 6.).—A motor nerve, arising
from the fused first and second ventral roots. It passes
through the intracranial ganglion, and leaves the exocci-
pital by a small foramen immediately above the main
foramen (indicated by a ring in the chart). It then passes
forwards over the top of the extracranial ganglion, rises
sharply at the side of the auditory capsule, and afterwards
turns forwards over the roof of the capsule to supply the
dorsal musculature and interspinal muscles. This nerve
does not anastomose with a sensory R. communicans lke
the posterior RR. spinosi.
* Stannius mentions only four roots in the Plaice also, having
apparently missed the first ventral, _
SEA-FISHERIES LABORATORY. 293
2. R. spinosus, ¢ (7. sy. c.).—Large motor nerve from
the third ventral root. It perforates the intracranial
ganglion dorsally, passes a little backwards in order to
leave the skull by the foramen magnum above, and then
courses forwards and upwards. Arrived at the roof of the
skull, it bends forwards over the latter, at first lying over
_ the epiotic a little to the side of the narrowed posterior
portion of the supraoccipital. It then fuses in the typical
manner with the sensory R. communicans of the second
spinal nerve, to form a conspicuous mixed nerve which
courses forwards over the roof of the skull near the middle
line to its distribution.
3. R. ventralis (”. v. 6+c).—This usually leaves the
skull by the main foramen, but it occasionally has a
foramen of its own situated below the main foramen, and
above the paroccipital condyle, as in the specimen figured.
It has a comparatively slight connection with the extra-
cranial ganglion, but the latter ganglion does undoubtedly
contribute fibres to it. The R. ventralis is formed as
follows :—First of all the remainder and greater part of
the first and second ventral roots, having passed under-
neath the intracranial ganglion, and together with some
sensory fibres, pass into the special foramen (indicated by
a ring in the chart). They are immediately followed by
the remainder of the third ventral root (also accompanied
by sensory fibres from the intracranial ganglion), which,
having perforated the intracranial ganglion, and instead
of passing into the main foramen as usual, turned down-
wards and entered the special foramen. ‘The ventral root
thus left the skull by all three foramina. These two mixed
trunks more or less unite in the foramen, and immedi-
ately outside it in this specimen bore a small number of
discrete ganglion cells. The latter, however, undoubtedly
belong to the extracranial ganglion. The two trunks soon
294 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
separate again into two mixed nerves, and pass downwards
and backwards. The lower one receives the R. communi- —
cans from the first spinal sympathetic ganglion (com. 1).
They subsequently unite again, and distal to the union a
large sensory and motor nerve is given off, which curves
downwards and forwards. This is the R. cervicalis or
so-called N. hypoglossus (7. cerv.). It courses at first at
the side of the pericardium opposite the junction of the
auricle and ventricle, and the upper sensory and the lower
motor components are quite obvious. In front, the two
components separate out into a dorsal sensory and a
ventral motor nerve. Shortly after giving off the above,
the R. ventralis receives a sensory and motor anastomosis
from the R. ventralis of the second spinal nerve (7. v. 21),
thus forming the brachial plexus. The compound trunk
(rv. v. 1) then courses downwards and slightly backwards,
and gives off a motor nerve in front and behind to the
muscles of the pectoral girdle (r. v.11 and vr. v. 17). It
now passes through the scapular fenestra (see fig. 8—
indicated by a ring in the chart), in order to reach the
external aspect of the pectoral girdle, where the two com-
ponents at once separate out into an anterior motor nerve
(7. v. 1°) and a posterior sensory nerve (r. v.1), wh ich are
distributed to the pectoral fin, the latter to its dorsal
region.
The following nerves arise from the extracranial
ganglion :—
1. R. communicans, b. (7. com. b.).—A large sensory
nerve from the extreme dorsal point of the ganglion. It
passes forwards over the roof of the skull at the same
transverse level as the R. spinosus, b., but external to 11.
It ultimately passes first outwards and then downwards
between the skull and the skin, and is distributed to the
latter in the region of the auditory capsule. As the R.
SEA-FISHERIES LABORATORY. 295
lateralis accessorius is absent in the Plaice, and as it
cannot anastomose with the R. spinosus, this nerve is not
an actual R. communicans in the Plaice. |
2. R. medius, b. (7. m. 6.)—Leaves the ganglion as
two distinct strands—an anterior sensory and a posterior
motor. The sensory section is small and passes outwards
and forwards to the skin in the region of the lateral
sensory canal. The motor section arises from the fibres
of the fused first and second ventral roots which have
passed underneath the intracranial ganglion, traversed
the main foramen lying underneath motor fibres from the
third ventral root, and perforated the extracranial
ganglion. Immediately it leaves the latter ganglion it
gives off a small anterior branch, whilst the rest of the
nerve passes laterally backwards and breaks up largely in
the dorsal musculature.
8. R. medius, c. (7. m. c.).—A large mostly motor
nerve arising almost entirely from the third ventral root.
The fibres pass through the main foramen, and perforate
and leave the extracranial ganglion at its anterior aspect.
Directly it leaves the ganglion, it gives off above a small
sensory thread, which passes outwards and backwards
towards the lateral sensory canal. The remainder and
larger part of the nerve courses downwards, outwards and
backwards in the dorsal musculature, in which most of its
fibres break up, except also a few that pass outwards
towards the skin.
The Seeond Spinal Nerve.
The second spinal nerve has a dorsal mostly sensory
(d. 2) and a ventral motor (v. 2) root, and two extra-
vertebral ganglia—a large dorsal ganglion (g. d. 2) and
a smaller ventral ganglion (g. v. 2). The dorsal root
passes backwards at once into the dorsal ganglion, but the
296 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
ventral root passes upwards and splits into two bundles,
one penetrating the dorsal, the other the ventral ganglion.
Both roots emerge from the atlas vertebra by a single ©
foramen (fig. 17).
The following nerves arise from the dorsal ganglion:
1. R. communicans (r. com. 2).—A sensory nerve
arising from the extreme dorsal tip of the dorsal ganglion.
Passes upwards and forwards, bends forwards over the
roof of the skull, and fuses with the R. spinosus e. of the
first spinal nerve (g. v.).
2. R. spinosus (7. sp. 2)—A motor nerve passing
upwards internal to the dorsal ganglion. After giving off
a fine motor twig below, which passes upwards external
to the dorsal ganglion (and not shown .in the chart), it
liberates in front and above a larger motor nerve which at
once splits into two bundles coursing laterally in the
dorsal musculature—one anteriorly and the other pos-
teriorly (see chart). Above, it receives the sensory R.
communicans from the third spinal nerve in the typical
manner, and bends forwards over the roof of the skull,
keeping very close to the middle line.
The following nerves arise from the ventral ganglion :
1. R. medius (7. m. 2).—A mostly motor nerve,
which perforates the ganglion, and then turns laterally
backwards in the dorsal musculature. It breaks into two
—one coursing in the dorsal musculature above the R.
lateralis profundus vagi, and the other crossing below it
into the lateral musculature, and supplying the muscles
in these regions. It seems to contain some sensory fibres
also. | .
2. R. ventralis (7. v. 2)—_A mixed nerve perforating
the ganglion and coursing downwards and backwards over
the kidney and approximating to the R. ventralis of the
first spinal nerve. It receives two Rami communicantes
SEA-FISHERIES LABORATORY. 297
from the second spinal sympathetic ganglion (com. 72.),
and sends a mixed bundle to the: R. ventralis of the first
spinal nerve as above described (7. v. 21). Just at about
the same place it fuses completely with the R. ventralis of
the third spinal nerve, but the above anastomosis 1s
derived from the R. ventralis 2, and contains no fibres
from 3. The compound trunk (7. v. 2+3), after giving off
a small branch to the inner surface of the clavicle (not
shown in the chart), courses forwards and downwards, and
gives off below two motor branches which pass at first
downwards and then forwards to supply the ventral
musculature. They anastomose with each other close to
their origin, and the posterior one (r. v.2+3') also anasto-
moses below with the R. ventralis of the fourth spinal
nerve. The remainder of the trunk then splits behind
into two—a small motor nerve and a larger mostly sensory
nerve. The latter (r. v.2+3"”) is continued backwards on
to the ventral portion of the pectoral fin.
five Lhaird, Spirnal, Nerve.
This spinal nerve has the usual two roots (d. 3 and
v 3), and a single very large extra-vertebral ganglion
(g. 3). Hach root has a separate foramen in the neural
arch of the second vertebra (fig. 17). The sensory R.
communicans (7. com. 3) contains a few motor fibres, which
are liberated as a small bundle for the dorsal musculature
(not shown in the chart). It fuses with the R. spinosus 2,
as above described. The motor R. spinosus (7. sp. 3),
after rising internal to the ganglion, courses at first back-
wards, fuses with the R. communicans 4, and then turns
forwards as a mixed nerve high over the roof of the skull
and very close to the middle line. It gives off below the
motor nerve to the dorsal musculature just like the pre-
ceding nerve.
298 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
The R. medius (r. m. 3) is a mixed nerve, but largely
motor. It breaks up into the two branches as in the
second spinal, the upper one for a time accompanying the
intermuscular bone, and the lower the R. lateralis pro-
fundus vagi (but not mixing with it).
The R. ventralis (7. v. 3) is also a mixed nerve. It
receives the R. communicans from the third spinal sym-
pathetic ganglion (com. 111), and then fuses with the R.
ventralis of the second spinal, as above described.
It is thus seen that the pectoral girdle and fin of this
specimen of the Plaice is supplied largely by the first
spinal, but also to a certain extent by the second and
third. It must, however, be emphasized that the limb
plexuses are subject to great variation, that the above
account is not a generalised description, and therefore
takes no account of variations. Stannius, however, states
that fibres from the RR. anteriores of the first three spinal
nerves pass to the pectoral fin in the Plaice.
With regard to the fifth spinal nerve, we need only
mention that the R. medius arises from the R. ventralis,
and that its lower division appears to completely fuse with
the R. lateralis profundus vagi, but really is only very
closely attached to it.
The innervation of the paired fins of Teleosts has very
important theoretical bearings. In the Plaice from
which the spinal nerves were plotted out, the R. ventralis
of the fifth spinal nerve, together with that from the sixth,*
were the nerves which supplied the pelvic fin. Now if
this fin is homologous throughout Teleosts generally,
* Stannius states that the pelvic fin of the Plaice is innervated from the
fourth and fifth spinal nerves, and this tallies with Cuvier’s scheme.
In our sections, however, the fourth spinal nerve was not connected with
the pelvic fin.
SEA-FISHERIES LABORATORY. 299
which we assume will not be doubted, then we must con-
clude that we have, in this clearly monophyletic group, a
genuine case of fin migration, since the pelvic fin of
Teleosts may be either abdominal, at the side of the anus,
thoracic, just behind the pectoral fin, or jugular, in front
of the pectoral. Further the fin must have moved from
behind forwards, since it may be clearly deduced from the
fossil forms that the abdominal position is unquestionably
more primitive than the jugular. Now in Elasmobranch
fishes, according to Gegenbaur’s hypothesis, the pelvic fin,
having been formed from the branchial skeleton, must
have migrated from before backwards, unless the addi-
tional hypothesis of the extension of the branchial region
further back than we have any knowledge, is evoked.t It
must be noted at once, first, that all paleontological evi-
dence is against such an assumption, and second, that this
migration, if it occurred at all, must have taken place at
a remote geological period. On the other hand, the
migration of the pelvic fin of the Teleost is not only some-
thing more than an hypothesis, but it must also have
occurred within comparatively recent times. Now several
attempts have been made to deduce the migration of the
Elasmobranch fin from its innervation, and so far the
Teleosts have been ignored, in spite of the fact that here
we might with much more reason expect to encounter
such evidence. Unfortunately, however, in the latter
group, the jugular pelvic, as in the case of the Plaice, is
supplied by the anterior spinal nerves of its region, and
the abdominal pelvic, as in the several fishes investigated
by Stannius, is supplied by the posterior nerves of its
+ It may, of course, be maintained, as it is in the case of some Elasmo-
branchs, that the pelvic fin of Teleosts migrated first backwards and then
forwards. We have ignored the former possibility (which after all would
be purely hypothetical), in order to concentrate attention on the latter,
where the migration theory may be the more satisfactorily tested.
B00 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
region. Here, therefore, the innervation clearly proves
nothing, and it may at least be doubted whether it proves
any more in the case of the Hlasmobranchs. We refer
now purely to neurological evidence, and are of course
aware that the supposed migration of the Hlasmobranch
fin is alleged to be supported by ontogeny also.
Stannius (op. cit.) makes several references to the
spinal nerves of the Plaice, and he quite realised the
morphological value of the anterior extremity of the dorsal
fin, since he carefully distinguishes between the forward
extension of mixed spinal nerves over the roof of the
cranium, and the sensory dorsal branches of the cranial
nerves themselves. His work also contains a figure of the
anterior spinal nerves of the Plaice (Taf. iv., fig. 1).
4.—T'nr Sympatuetic Nervous System (Fig. 26).
Owing to the impossibility of satisfactorily dissecting
the anterior portion of the sympathetic, we plotted it out
from the same series of sections as were used in the case
of fig. 25. As it is drawn to the same scale, the two figs.
may therefore be compared. Our examination of the
sympathetic commenced at the sixth vertebra, and. behind
the seventh spinal nerve. It is described from behind
forwards, right side first.
The sympathetic cord may be conveniently divided
into two parts, which we will call the cranial sympathetic,
associated with the skull and cranial nerves, and the
spinal sympathetic, associated with the vertebral column
and spinal nerves. In each portion, the ganglia are
numbered separately from before backwards.
At the sixth vertebra the sympathetic is situated
laterally below the centrum and the transverse process.
It here sends a short Ramus communicans to the ventral
ramus of the seventh spinal nerve (com. vu.), which
SEA-FISHERIES LABORATORY. BOL
crosses it at right-angles. In front of this is found the
seventh spinal sympathetic ganglion (7’). At this region
the two cords are connected by a transverse commissure
below the dorsal aorta and bearing a pair of ganglia (7”),
formed as shown in the figure, and the cord of the right
side is also looped. ‘There are two RR. communicantes to
the ventral ramus of the sixth spinal nerve (com. v.), but
in front of this, beyond a loop for a renal vein and a very
small ganglion in front of ganglion 5 (5’), there are no
features of special interest until we come to the second
spinal sympathetic ganglion.
The sympathetic behind the second ganglion lies
immediately above the inner dorsal angle of the kidney.
The coeliac ganglion (g. coel.) lies close under the second
spinal sympathetic (2’), and in front rises up to fuse with
it. Jour nerves arise from the second ganglion. Behind,
a pair (com. 7.) pass independently into the ventral ramus
of the second spinal nerve, and thus form RR. communi-
cantes 11. The sympathetic now les internal to the
kidney, and just above the cceliaco-mesenteric artery.
In front, a large third nerve arises dorsally, and soon splits
into an anterior and a posterior branch. The former is
continued into the first ganglion (1’) and thereafter into
the cranial sympathetic, whilst the latter forms a promi-
nent. ganglionated (2”) commissure under the dorsal aorta
with the cord of the other side. ‘The fourth branch arises
anterior to the third, and curved backwards on to the
aorta, where it was lost. The second ganglion now tapers
down, and terminates in close proximity to the kidney.
The coeliac ganglion, which it should be noted arises
from the rzght sympathetic cord, passes backwards after
fusing with the second ganglion, and is situated just over
the coeliaco-mesenteric artery. It also gives off four
branches, The most dorsal one passes straight into the
302 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
kidney after a very short course. Of the three others two
join to form the dorsal Nervus splanchnicus (n. sp.’) lying
over the above artery, but before joining one of them
gives off a thin twig which accompanies the esophageal
artery. The fourth branch, after giving off a fine twig
to the kidney, becomes the ventral N. splanchniecus
(n. sp.”), lying under the artery. The latter nerve is for
some part of its course opposed to the R. intestinalis of
the vagus. When the coeliaco-mesenteric artery divides
into a dorsal coeliac and a ventral mesenteric artery, the
two RR. splanchnici also divide (ep. figure).
From the first spinal sympathetic ganglion (1’) three
nerves arise. One of these is certainly, and another pos-
sibly, a R. communicans to the ventral ramus of the first
spinal nerve (com. 1). The third seemed to enter the
jugular ganglion of the vagus, but this is not certain.
From sections 730 to 704 the cord is attached to the inner
surface of the root and ganglion of the Truncus branchialis
primus N. vagi, but as far as could be ascertained
exchanged no fibres with it. The first spinal sympathetic
ganglion occupies an intermediate position between the
cranial and spinal sections of the cord, since it is con-
nected both with the vagus and first spinal nerve.
After leaving the first spinal ganglion, the cord is
continued forwards as the cranial sympathetic, and from
section 702 to 678 accompanies the superior jugular vein,
during which it bears a very small ganglion (8). After
leaving this vein it bears ganglion 7 and becomes attached
to the inner surface of the glossopharyngeus ganglion and
trunk (658-620), being wedged in between the latter and
the skull, and bearing ganglion 6. In front again, when
the glossopharyngeus splits up, it accompanies the ventral
edge of Jacobson’s anastomosis (618-560), and swells into
a very large ganglion (5) very closely related to Jacobson’s
SEA-FISHERIES LABORATORY. 303
anastomosis. On leaving the latter it bears another
moderate-sized ganglion (4), but no fibres were seen to be
exchanged between any of these ganglia and the glosso-
pharyngeus nerve. In front of ganglion 4, the cord rises
upwards and becomes attached to the Truncus hyoman-
dibularis, just as the latter emerges from the skull, the
post-trematicus vii. lying below it. It now passes into
the cranial cavity through the jugular foramen, and is
so closely pressed against the T. hyomandibularis that we
were unable to determine whether fibres were exchanged
or not, although we believe not. Inside the cranium, it
bears the small ganglion 3, from which the ganglionated
intracranial most anterior commissure (3”) arises. The
commissural ganglion is situated actually on the root of
the sixth cranial nerve.
From section 536 to 494 the cranial sympathetic
accompanies the R. palatinus facialis, and is very closely
attached to it. In front, it passes through the trigemino-
facial foramen, and takes up a position between the skull
and the origins of the maxillary and mandibular v. nerves.
It now swells into the large ganglion 2, from which a very
prominent R. communicans (com. v.') passes upwards to
the T. maxillo-mandibularis. The first cranial ganglion
(1) lies above the second, and is connected with it by a
very short strand of fibres. Both the first and second
ganglia give off a cord in front, but the two unite before
reaching the ciliary ganglion. The first ganglion also
gives off a nerve internally, which accompanies the ventral
edge of the R. ophthalmicus superficialis v. The possibly
corresponding nerve of the other side arises externally
from the second ganglion, accompanies the superior
maxillary v., and has a very small ganglion of its own.
From the first cranial ganglion onwards the sym-
pathetic is accompanied by the profundus nerve, They
BO4 TRANSACTIONS LIVERPOOL. BIOLOGICAL SOCIETY.
pass together through a special foramen in the ventral
edge of the alisphenoid into the eye muscle canal. The -
cord from the second ganglion also enters the canal by
the same foramen. Before reaching the ciliary ganglion
the profundus nerve separates from the sympathetic as the
Ramus ciliaris longus (see profundus nerve), but some
fibres are dispatched from it to accompany the sympathetic
to the ganglion as the Radix longa. The ciliary ganglion
itself (c2/. g.) is closely attached above to the main trunk
of the oculomotorius, after the latter has given off the
nerve to the rectus superior. The Radix brevis therefore
is exceedingly short (rv. 6.). From the ciliary ganglon
in front arises the R. ciliaris brevis (c/. 6.). This passes
forwards in the eye muscle canal, accompanying the main
trunk of the oculomotorius, until the latter breaks up. It
then courses under the lower or right optic nerve as a
conspicuous bundle, enters the eye ball with it, and there-
after passes downwards and forwards towards the iris.
As regards now the eyeless or left side, the sym-
pathetic nervous system, like the nervous system
generally, is not so well developed. This is especially
noticeable in the gangha, which are perceptibly smaller
than those of the other side. In front, the disturbance
of the symmetry has dragged the sympathetic over to the
ocular side. Generally speaking, however, the left s:de
resembles the right in all essential respects, but the fol-
lowing differences may be mentioned.
In the spinal sympathetic the seventh ganglion (7)
is in two parts, R. communicans vi. (com. v2.) is separated
from its ganglion (6’), and R. communicans v. (com. v.) is
situated between a large and a small ganglion (5! and 5").
Ganglion 2 gives off externally a large nerve which passes
‘backwards and downwards to the kidney. R. communi-
cans ii. (com, it.) is single, but the first (com. 7.) is however
SEA-FISHERIES LABORATORY. 305
double, the posterior of which bears a very small ganglion.
No exchange of fibres between the sympathetic and the
vagus was observed.
In the cranial sympathetic only 7 ganglia were found
instead of 8. When the cord reaches the glosso-
pharyngeus, instead of becoming attached to the ventral
border of the ganglion and subsequently to that of Jacob-
son's anastomosis, it passes upwards internally to the ixth
and becomes opposed to its upper division. This is due
to the fact that when the ixth splits it forms a dorsal
Jacobson’s anastomosis and a ventral post-trematicus,
instead of the reverse as on the right side, and the
sympathetic always accompanies the former. Ganglion 5
hes quite clear of and above the glossopharyngeus, in
striking contrast to the condition on the other side. As
the cord passes through the jugular foramen it is for a
time very tightly wedged into the angle formed by the
outgoing post-trematicus vil. and the hyomandibular
trunk. We could not determine whether there was any
exchange of fibres between the sympathetic and the facial
nerve, but if present it is nct obvious. There is a large
R. communicans (com. v.') to the base of the T. maxillo-
mandibularis.
The combined sympathetic and profundus nerve when
they enter the eye muscle canal lie just above the ciliary
ganglion. Instead, however, of passing straight down to
the ganglion, as on the right side, they curve round the
left rectus externus muscle, and describe an almost com-
plete circle before reaching the ganglion. The few fibres
forming the Radix longa and the sympathetic join with
the fibres leaving the ciliary ganglion to form the R.
ciliaris brevis. It is doubtful whether many of them
enter the ganglion at all on this side. There are no other
differences of importance between the two sides.
Y
306 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
We are unable to agree with some of the remarks of
Stannius on the sympathetic of the Plaice. He states that
the first cranial ganglion is that connected with the facial
nerve, that there is no ganglion corresponding to the
glossopharyngeus, and that the rami communicantes for
the first 3 or 4 spinal nerves arise from a common ganglion
also giving origin to the NN. splanchnici. We have not
examined the sympathetic posteriorly, but Stannius states
that there are very large sympathetic nerves connected by
a commissure perforating the kidney to reach the repro-
ductive organs. ‘They also pass backwards with the ovary
or testis into the cavity between the skeleton and the skin
formerly supposed to be the posterior extension of the
body cavity.
The sympathetic nervous system of Fishes has
recently been investigated in some detail by Jaquet* and
C. K. Hoffmannt—the former studying its anatomy and
the latter its development. Jaquet divides it into cephalic,
abdominal and caudal portions. The first is stated to be
connected with the ganglia of five cranial nerves—the
“hypoglossal” [first spinal], vagus, glossopharyngeus,
facialis and trigeminus, and fibres from the second and
third ganglia are said to accompany the glossopharyngeal
to the pseudobranch. Jaquet’s work contains a formal
scheme of the Teleostean sympathetic (fig. 4), and also
many statements which are not borne out by our examina-
tion of the Plaice, and which seem to us to require con-
firmation. The most important work on the anatomy of
the sympathetic in bony fishes is that of Chevrel,t who
investigated the relation of the ganglia to those of the
cranial nerves, and who asserts that the first sympathetic
* Bull. Soc. Sci. Bucarest-Roumanie, Ann. x., 1901.
+ Verhand. K. Akad. Wetens. Amsterdam, Sect. ii., Dl. vii., 1900.
t Arch. Zool. Expér., Ser. ii., T. v. bis.
SEA-FISHERIES LABORATORY. 307
ganglion is always associated with the trigeminus, except
in the Physostomi, where there are no ganglia in front of
the vagus. This is what we should expect, as the cranial
sympathetic appears for the first time in the bony fishes,
and the Physostomi are undoubtedly a primitive oe
of Teleosts.
F.—THE SENSE ORGANS.
1.—Tuer System oF LATERAL SENSE ORGANS
oR SENSORY CANALS.
(Figs. 23 and 29.)
The obvious line seen at the side of the body in most
Fishes, including the Plaice, and known as the lateral
line (Seitencanal of German authors), is in our type a
long tube or lateral canal, protected by a row of modified
scales (lateral line ossicles), and opening on to the surface
by pores at more or less regular intervals. ‘These pores
may open directly into the canal or they may do so by the
intermediation of a little tubule. At first the only sub-
stance found in such a canal as this was a quantity of a
jelly-like mucus, and hence these canals were called
mucous canals, and were supposed to secrete the mucus
on the surface of the body. The discovery, however, that
they contained large sense organs, one of which usually
occurred between two succeeding surface pores, and thai.
the mucus was only of minor importance, and developed
by the numerous goblet cells in the lateral canal itself to
enable the sense organs to perform their function, and also
that the mucus in the lateral canal was of quite a different
character to that occurring on the surface of the body,
conclusively proved that these lateral canals constituted a
sensory structure and could not therefore be called mucous
308 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
canals. We hence adopt the term of sensory canals
originally proposed by Ewart.
Now the sensory canals are not confined to the body
of the fish, but always extend on to the head, where, as a
very general rule, they form a much more complex and
important system of sensory canals, which, on account of
their deeper situation and therefore less obvious character,
are too often disregarded. In the Teleostean Fishes the
innervation of this system is so remarkably constant in
those forms in which it has been properly investigated as
to justify its division on each side of the body into the
following four canals, the extent of any one of these being
determined by its innervation. That is to say, that part
of the cephalic system of sensory canals called the infra-
orbital canal is precisely that part of the system innervated
by a single perfectly definite nerve—the R. buccalis
facialis. One extremity of this canal is a natural blind
extremity, the other is the artificial boundary beyond
which its nerve does not extend. The four canals are:—
(1) the lateral canal at the side of the body (“ lateral line”
of systematists), defined by the branching of the R.
lateralis vagi; (2) the supraorbital canal over the eye,
defined by the R. ophthalmicus superficialis vil.; the
infraorbital canal under the eye, defined by the R.
buccalis vii.; and the hyomandibular canal on the oper-
culum and lower jaw, defined by the R. mandibularis
externus vii. These nerves are in this work only provi-
sionally associated with the vagus and facial nerves, as
their true morphological value cannot be discussed in a
general treatise of this nature.
Although much work has been done on the use of this
undoubtedly sensory apparatus, its function is even yet a
subject for speculation. This is due to the fact that
owing to its very diffuse nature and the intimate relations
SEA-FISHERIES LABORATORY. 309
of its nerves with the other cranial nerves, it has so far
been found impossible to devise really satisfactory experi-
ments. FF. 8. Lee, the latest investigator of the function
of the lateral line organs, concludes that they are con-
nected with the sense of pressure or equilibration, and
even if this be not the case, there is some reason to doubt
whether the latter can be located in the semi-circular
canals as in higher vertebrates.
The Lateral Canal (/at. c.)—This canal, in part the
“lateral lne”’ of systematists, is supported during the
greater part of its length by modified scales. Arrived at
‘the region of the shoulder girdle it tunnels through the
post-temporal, and then for a short distance has no bony
support. It now enters a chain of ossicles, undoubtedly
metamorphosed scales, called supratemporal ossicles or
extrascapule. The last or most posterior supratemporal
is attached to the dorsal surface of the pterotic at the
region of the posterior depression shown in fig. 1, and is
larger than any of the others. It consists of 2 parts, one
running longitudinally in a curve for the “ lateral line,”
and the other transversely and somewhat forwards for the
terminal portion of the supratemporal canal. Whilst in
this ossicle the lateral canal on the ocular side anastomoses
with the posterior extremity of the infraorbital canal, and
then turns abruptly upwards almost at right-angles, and
afterwards forwards, the latter or anterior portion of the
canal being called by some authors the supratemporal
canal (s. ¢. c.). The last supratemporal ossicle of the
Plaice therefore corresponds to the second, third and
fourth of the Cod fused together. In one Plaice examined
there were in all 13 supratemporal ossicles on the ocular
side, as described by Traquair, but the recurrent portion
of the canal, usually present at its anterior extremity in
the adult (see figs. 23 and 29) was absent in this specimen.
310 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
The condition of this recurrent canal, it may be men-
tioned, varies considerably. On the eyeless side the rela-
tions of the supratemporal canal to the ossicles was essen-
tially the same. The sections revealed a curious absence
of sense organs in the anterior portion of the supra-
temporal canal of the ocular side (fig. 23), there being only
4 sense organs as against 13 pores, but the canal on both
sides of the body was not completely developed, like the
infraorbital. On the eyeless side in the sections there
was a break in the middle of the supratemporal canal
occupied by three naked sense organs, only two of which,
however, seemed to be canal organs. This break is of
course converted into a canal later on in the ontogeny.
The recurrent canal was also absent, and there were only
eight pores as against 13 on the ocular side, although
there were at least 7 sense organs as against 4, not count-
ing the three naked sense organs above. The relative
position of the sense organs was also different. In the
lateral line itself the only difference of importance
between the two sides was that the third or last otic sense
organ of the ocular side was here innervated from the R.
supratemporalis vagi, and hence belonged to the lateral
canal, as in the Cod.
Infraorbital Canal (zn/. c.).—After leaving the last
supratemporal ossicle, in which this canal on the ocular
side anastomoses with the lateral, it at once enters the
pterotic, and immediately receives the hyomandibular
canal, which comes up from below. There is no separate
dermal pterotic as occasionally occurs in the Cod. The
canal passing straight forwards, traverses the pterotic,
sphenotic and right frontal. Arrived at the space between
the first and second tuberosities (fig. 1) it anastomoses
with the right supraorbital canal and turns sharply down- _
wards almost at right angles, afterwards curving forwards
SEA-FISHERIES LABORATORY. oe
under the eye. After leaving the frontal the canal is pro-
tected only by the chain of very slender suborbital ossicles.
the posterior of which are sometimes called postorbitals,
and the last of which is attached to the frontal. These
ossicles are much more conspicuous in the Cod. In one
specimen examined there were 18 suborbitals on the ocular
side. On the eyeless side the suborbitals are both fewer
and larger, nor does the canal take such a wide sweep
forwards, and is hence shorter (cp. fig. 29). It leaves the
frontal in front almost exactly opposite the exit of the
right infraorbital. From this point the canal extends
forwards in a slight curve until it reaches the left
lachrymal to which the first suborbital ossicle is attached.
On the ocular side the lachrymal is quite distinct from
the suborbital chain, and in the specimen examined the
canal ended by a pore 11mm. behind and below the postero-
ventral extremity of the lachrymal. On the eyeless side
the canal passes on to the left lachrymal, on which it
terminates. ‘There were 5 suborbital ossicles on this side,
but three of these were each divided into two. ‘Traquair
describes 13 on the ocular side, and 8 on the eyeless. In
the sections the right infraorbital canal was not com-
pletely developed, the first 7 sense organs being yet
unenclosed in a canal, but lodged in small depressions of
the skin. The supratemporal and infraorbital canals are
therefore the last to be completed. ‘The portion of the
P)
canal in line with the “ lateral line,” and innervated by
the R. oticus facialis, contained 3 sense organs on the
ocular side, to the last of which attention may be drawn.
On the eyeless side anteriorly the canal courses down-
wards, but after leaving the lachrymal it turns sharply
backwards almost at right angles. The whole canal is
completely developed on this side, and is more robust.
Its anterior portion has fewer sense organs, but those it
312 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
has are arranged more definitely with regard to the pores,
z.e., there is always one sense organ between two adjacent
pores, except between pores 2 and 38, where a sense organ
was absent. The part of the canal innervated by the R.
oticus vil. also differs from that of the ocular side in that
it has 5 pores, between the first two of which no sense
organ was found, and only the first two sense organs
were innervated by the R. oticus vil. The sense organ
corresponding to the third or last otic was on this side
innervated from the R. supratemporalis x., and hence
belonged to the lateral canal, as in the Cod.
Hyomandibular canal (hy. c.)—This canal anasto-
moses behind on the pterotic with the infraorbital on the
ocular side, and the lateral on the eyeless side, as above
described. It passes forwards for a little and then turns
sharply downwards on to the preoperculum. It courses
downwards parallel with the anterior edge of the pre-
operculum, turns abruptly forwards with the same, and
finally passes over the articular on to the dentary, on
which it ends far in front by a pore. The positions of the
sense organs and pores are shown in the chart. The
canals of the two sides agree in all essential respects,
except that in the sections, pore 7 was found to be want-
ing. The full complement of sense organs, however, was
present. .
Right Supraorbital Canal (swp. c.)—This is the only
complete supraorbital in the Plaice, the left being repre-
sented only by vestiges. It anastomoses with the right
infraorbital between the first and second tuberosities on
the frontal, and passes forwards for a short distance, and
then gives off almost at right-angles the supraorbital
commissure (s. 0. ¢.), to join the supraorbital canal of the
other side. It then passes forwards in the substance of
the right frontal, leaves this in front and passes on to the
SEA-FISHERIES LABORATORY. — 313
right nasal, on which it ends by a pore. It has only 3
pores and 4 sense organs, omitting those in the commis-
sure. It is curious to find that opposite the entry of the
commissure there is a small blind diverticulum, containing
no sense organs, and corresponding exactly to a similar
structure found in the Cod (see fig. 23).*
The Left Supraorbital (swp. c.’)—Anastomoses with
the left infraorbital just as on the opposite side, passes
forwards within the left frontal for a short distance, and
receives the commissure. Just opposite the latter point
it gives off a surface pore below which may correspond to
the blind sac of the ocular side. Between its anastomosis
with the left infraorbital and reception of the commissure,
it has one large sense organt but no pore (cp. other side,
fig. 23). In front of the commissure the canal leaves the
frontal, but still lies in a depression on it, and ends
blindly a short distance anterior to the commissure. This
description enables us to compare the condition in the
Plaice with that of the T'urbot, as described by Traquair,
and to correct the latter’s figure of the Plaice in some
shght particulars. The other supposed remnant of the
left supraorbital canal, discovered by Traquair, is situated
far in front on the ocular side of the body very near the
dorsal edge and above but a little behind the anterior
extremity of the right supraorbital (figs. 23 and 29,
sup. ¢."). It consists of a very small follicle situated,
according to Traquair, on a minute ossicle representing a
greatly reduced left nasal, and containing two surface
pores, and, according to our sections, one sense organ.
* Cole, Trans. Linn. Soc., ser. ii., vol. vii., pp. 157 and 180.
+ This sense organ, as well as the one on the left side of the supraorbital
commissure, is innervated by the R. ophthalmicus superficialis vii. of the
left side. This is quite a conspicuous nerve, in spite of the abortion of
the greater part of its sensory canal. There can, therefore, be no question
that these parts of the canal system belong to the supraorbital canal.
314 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
As, however, in the single series of sections on which fig.
23 was based it was innervated by the inner buccal of the
right side, it either cannot represent the anterior end of
the left supraorbital, or such an innervation must be
anomalous. In the meantime, however, we shall follow
Traquair, and regard it as belonging to the supraorbital
system. Another very small follicle was found behind it,
but it was very aborted and contained no sense organ.
The innervation of the former structure suggests that it is
a modified pit organ, especially as such occur typically in
Teleosts at this region. -
The Supraorbital commissure (s. 0. c.).—Arises from
the canal on the ocular side, as above described. A sense
organ is situated just at its origin, which projects partly
into the supraorbital canal itself. The commissure passes
upwards and forwards almost at right-angles in the sub-
stance of the right frontal. It then bends sharply inwards
at right angles (indicated by a circle in fig. 23), and at
once enters the left frontal. Just at the turn an unpaired
surface tubule (3) is given off, and this undoubtedly cor-
responds to the fourth unpaired median tubule of the Cod.
Its position in the Plaice is only apparently anomalous.
The commissure passes almost transversely but slightly
forwards across the body in the left frontal. Arrived at
the other side it bends gradually downwards but stall for-
wards (a large sense organ being situated at the turn), and
thus passes into the left supraorbital. ‘he sense organ in
the commissure on the left side is situated much higher
up than on the other side, and is thus entirely within the
commissure. It is innervated by the R. ophthalmicus
superficialis vii. of the left side. The commissure also is
passing forwards from right to left during the whole of its
course.
To sum up the supraorbital system, the right supra-
SEA-FISHERIZS LABORATORY. 815
orbital canal has 3 pores and 4 sense organs, the left supra-
orbital 3 pores and 2 sense organs, and the supraorbital
commissure one median pore and a pair of sense organs.
Only the two extremities of the left supraorbital canal are
present, the whole of the intermediate portion having
aborted with the corresponding part of the left frontal.
The first two pores and first sense organ of the left supra-
orbital appear to correspond to the same on the right.
The whole supraorbital system is supphed by the two RR.
ophthalmici superficiales vii.
Besides the sense organs situated in the sensory
canals, or canal organs, there are two other series of naked
sense organs situated on the skin. These are known as
Pit Organs and Terminal Buds. The former belong to
the lateral line system, and are innervated by one or more
of the four lateral line nerves. The latter are quite dis-
tinct from the lateral line organs, and are innervated by
an entirely separate system of nerves, the Ramus lateralis
accessorius (= R. lateralis trigemini), belonging to the
communis system. ‘The terminal bud system has been
reduced in the Plaice.
2.—Tux Noss (Fig. 25).*
The olfactory organ of both sides is described as if
viewed from above, and not from the side. The external
apertures of the nose, two on each side, are not symmetri-
cally placed, and those of the left side are situated almost
on the apparent mid-dorsal line of the body, immediately
to the left of the anterior border of the left eye. The
two apertures or nostrils of each side are sometimes called
anterior and posterior nares, but the latter term is
obviously inadmissible.
*For the olfactory organs of the Pleuronectide, see Kyle, Jour. Linn.
Soe., xxvii., and 18th Ann. Rep. Fish. Board Scotland, 1899, Part iii.
316 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
Right Olfactory Organ.
Anterior Nostril (a. nos.)—A small aperture situated
on the anterior aspect and almost at the apex of a largish
tube.
Posterior Nostril (p. nos.)—A large aperture only
slightly raised above the surface of the body.
Both nostrils open into a large nasal chamber (n. ch.),
the external wall of which is perceptibly thickened, and
the internal wall of which is thrown into a vertical series
of large folds or olfactory lamine (0. /am.). These
lamin bear the olfactory cells and sensory hairs, to which
the olfactory nerve is distributed (n. olf.), and run in a
longitudinal direction. The nasal chamber is therefore
the sensory chamber of the nose, and in most fishes is the
only one present. There were 9 olfactory laminz in the
right nasal chamber in our sections, but the most dorsal
and ventral one is very small.
Into the nasal chamber open the nasal sacs, the walls
of which are non-muscular and non-sensory, but contain
innumerable goblet cells. They therefore have a secretory
function at least. ‘l'hese sacs are as follows :—
Dorsal nasal sac (#7. sac.1)—Opens into the nasal
chamber behind and above. Passes forwards and bifur-
cates. The inner limb soon terminates, but the outer one
passes far forwards, and although it is very narrow from
side to side, it is very wide from above downwards. Its
true extent therefore does not appear in the figure.
Antero-ventral nasal sac (7. sac.”).—Has a common
opening with the postero-ventral sac into the nasal
chamber behind and below. Its outer wall is continued
backwards into that of the third sac. Passes far forwards,
narrow from above downwards, but wide from side to side,
between the mucous membrane of the mouth and the
3 SEA-FISHERIES LABORATORY. Sy
palatine bone. In front a portion is sent upwards inter-
nally at right-angles to the main portion and internally to
the palatine. This soon terminates, and the remainder of
the sac ends bluntly below the palatine.
Postero-ventral nasal sac (n. sac.*).—Opens into the
nasal chamber as above described. It is very irregular in
shape, and three-rayed in transverse section. It passes
far backwards just above the mucous membrane and to the
right of the palatine, being narrow behind and ending
blindly just over the mucous membrane of the mouth
below and internal to the sclerotic of the right eye.
imeit Olfactory Organ.
The anterior and posterior nostrils (a. nos.', p. nos.')
are no different from those of the right side, except that
the anterior tube is smaller and the posterior nostril is
larger and more widely open.
The left nose is situated at a transverse level posterior
to that of the right, and is further much less developed.
This is most evident in the nasal chamber (n. ch.*), which
is obviously smaller and was in the sections only thrown
into 4 olfactory lamin (0. /am.'), the dorsal one of these
being quite small and the ventral one smaller than the
two intermediate lamine.* ‘The figure does not admit of a
- comparison as regards the nasal sacs, since their dimen-
sions from above downwards cannot be shown.
There are only two nasal sacs on the left side as
follows :—
Dorsal nasal sac (vu. .sac.‘).—Arises from the nasal
chamber dorsally from behind. At first its shape in trans-
verse section is that of an inverted right-angle—the verti-
*The difference between the two olfactory organs is seen in the
diameter of the right and left olfactory nerves (fig. 25, 1. olf., n. olf.').
The figure only illustrates the difference in diameter, the difference in
bulk is even greater.
318 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
cal limb lying between the nasal chamber and the inter-
maxillary cartilage, and the horizontal limb passing
inwards over the top of the cartilage. In front, however,
the sac hes wholly on the top of the cartilage fitting over
it in a curve like acap. It ends very bluntly in front.
Ventral nasal sac (7. sac.°).—Its position in the figure
is somewhat diagrammatic, as it is really situated under
the nasal chamber and only partly under the dorsal sac.
It arises from the chamber ventrally from behind, and
also passes forwards. It is of very irregular shape, and
gives off externally a small limb which soon terminates.
Its true extent does not appear in the figure, as it is
situated obliquely dorso-ventrally. It narrows very much
in front and ends blindly near the outer skin, and between
it and the intermaxillary cartilage.
There are no true posterior nares such as Kyle
describes in one specimen of a Cynoglossus. The nasal
sacs discharge their contents by the action of the jaw
apparatus, and apparently fill again with sea water by the
latter simply passing into the nasal chamber, and thence
into the sacs, when the animal is swimming. No intrinsic
muscular action is involved, nor are the nostrils valved.
The non-fixed parasitic Copepod Bomolochus solee,
Claus, is not infrequently found in the nasal chamber of
the Plaice.*
o.—— | HE. YES.
We have only space to consider those features in the
structure and relations of the eyes and their accessory
organs which are peculiar to Pleuronectid fishes, and are
in some way associated with the asymmetry of the head.
The eyes are situated very near the anterior limit of the
*For figures, see T. Scott, Eleventh Report Fish. Board Scotland,
pl. v., figs. 1-10.
SEA-FISHERIES LABORATORY. 319
eranium, and the lower or right eye is slightly in front of
the upper or left. The prominent interorbital ridge
formed by the frontal is continued a little way round in
front of each eye, that portion in front of the left being
formed by the mesethmoid and left prefrontal, and that in
front of the right eye by the right prefrontal. The inter-
_ orbital ridge is continued backwards into the line of
tuberosities. In the dead fish each eye lies in a little
concavity, and the skin round it is loose and thrown into
folds. This appearance may also be seen in the living
fish, but it will be noticed that the eyes often project very
markedly from the surface of the head, and that their axes
may be parallel or even convergent, while after death they
are widely divergent. There are no eyelids, and the
cornea is flattened.
The orbits.—The left orbit (fig. 1) is bounded inter-
nally by the right frontal and an anterior process of the
left frontal, anteriorly by the mesethmoid and left pre-
frontal, externally by the processes of the left frontal and
prefrontal forming the pseudomesial ridge of Traquair,
and posteriorly by the left frontal. When the cranium is
placed dorsal surface uppermost the left orbit looks
upwards and to the right. The right orbit is not bounded
completely by bony walls as is the case with the left.
Only internally and anteriorly do the bones adjacent to it
lie close to the skin. Those are the right frontal and
prefrontal. The bony structures external and posterior to
the orbit are the parasphenoid bar and the alisphenoid.
All these bones lie nearly in one plane, and the external
and posterior walls of the orbit are formed by strong
muscle masses. When the cranium is held dorsal surface
uppermost the right orbit looks downwards and slightly
laterally.
The interorbital septum is formed by the right
320 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
frontal and prefrontal above, and by the ethmoid cartilage
below. As seen in the dried skull (fig. 3) these structures
bound a large fenestra. A membranous sheet stretches
across this fenestra from the ventral edge of the right
frontal to the ethmoid cartilage and completes the septum.
In front the ethmoid cartilage is perforated by a wide
opening. This is the ethmoidal fenestra. It is seen in
fig. 3, and through it the internal surface of the left pre-
frontal may be seen in the figure. When the cranium is
held dorsal surface uppermost the interorbital septum is
almost exactly horizontal.
The Recessus orbitalis.—This is the term applied by
Holt* to an accessory of the organ of vision present in all
Pleuronectid fishes. It is an evagination of the mem-
branous wall of each orbit forming a sac which les outside
the orbit and the cavity of which communicates with that
of the former by one or more openings. The recessus of
the right eye les immediately behind the bulb and just
underneath the interorbital septum. To expose it the
skin must be very carefully removed from the “region
immediately behind the eye from the interorbital ridge
downwards. On removing a little connective tissue the
organ is then seen. It is a conical sac of fatty appearance
with the apex directed backwards. In a fish of about
22 inches in length it is about lem. in total length in the
contracted condition. On cutting open its outer wall its
cavity is seen to be somewhat reduced by bands of muscle
fibres which cross it and are massed together on the
internal wall. A seeker can be passed from its cavity into
that of the orbit. On cutting away the skin round the
eye and carefully removing the latter after dividing the
optic nerve and eye muscles, the opening of the recessus
can be seen immediately above the place where the
*Holt—Proc. Zool. Soc., No. 29, 1894, pp. 413-446
SEA-FISHERIES LABORATORY. 321
external and inferior recti enter the orbit, and where the
cavity of the latter is prolonged backwards for a littie
distance round the recti.
The recessus of the upper or left orbit has similar
relations, but on account of the almost complete enclosure
of the latter by bony structures it has a somewhat different
position. It hes on the eyeless side of the head external
to the fenestra bounded by the left frontal, left prefrontal,
parasphenoid and alisphenoid. It must therefore be dis-
sected from that side and is easily exposed by simply
removing the skin and a little surrounding connective
tissue. It is (in a preserved fish of 22 inches long) a
round flattened sac of about 2cm. in diameter, of similar
appearance and structure to the organ of the right side.
li also opens into the orbit, and on removing the left eye
the large aperture is easily seen immediately posterior and
slightly above the place of origin of the inferior oblique
muscle. It is situated beneath the pseudomesial ridge
and pierces the soft wall of the fenestra mentioned.
We have stated that the eyeball can be protruded
from the general surface of the head to a remarkable
extent. Now while the eye muscles provide an effective
apparatus for the retraction of the eye, there is apparently
no muscular arrangement which can bring about protru-
sion. ‘This appears to be the function of the recessus. In
life the cavities of the orbit and that of the recessus with
which the latter is in free communication are filled by
fluid which apparently originates by an infiltration of
lymph from the capillaries outside the orbital wall. . The
wall of the recessus being markedly muscular, it follows
that its contraction will expel the contained fluid into the
orbit and press on the internal surface of the eye-ball.
Since the skin of the head round the eye is loose it yields,
and the eye is accordingly protruded. Conversely the
Z
B22, TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
relaxation of the wall of the recessus and the contraction
of the eye muscles effect the retraction of the eye-ball. If
the eye in a fresh or living fish be gently pressed fluid
passes into the recessus from the orbit and the former can
be seen to swell.
The eye muscles (text-fig. 5) are the usual six pairs,
two pairs of oblique muscles, and four pairs of straight
muscles or recti.
The superior oblique muscles (Ob/. Swp.).—Both right
and left muscles take origin on the left side of the head.
Tt will be remembered that the left prefrontal sends back-
wards a long process which fits into a groove on the dorsal
surface of the parasphenoid. At the beginning of this
process the prefrontal is deeply grooved for the reception
of the ethmoid cartilage, the groove being formed by two
horizontal bony lamine, and on the upper of these laminze
and on the adjacent anterior concave surface of the pre-
frontal the oblique muscles take origin. The left superior
muscle passes upwards and slightly backwards along the
left side of the interorbital septum to its insertion on the
eye-ball. The right muscle, however, immediately passes
through the ethmoidal fenestra and so through the inter-
orbital septum to the right orbit. It then passes upwards
and backwards, diverging slightly from the left muscle,
along the right side of the interorbital septum to its inser-
tion in the right eye-ball.
The insertion of these muscles is peculiar. Hach
spits up near its distal extremity into anterior and
posterior slips. The anterior slips (06l. swp.), which are
the larger of the two, have wide insertions on the superior
and anterior surfaces of the eye-balls. The posterior slips
(o. s. a.) curve round the internal and superior surfaces of
the eye-balls, crossing over the insertions of the superior
SEA-FISHERIES LABORATORY. : 323
Text Fic. 5. Dissection of the Kye-Muscles. x3.
The Cranium is seen from the dorsal surface and slightly from the left
side. The eyeballs have been pulled out from the orbits.
: VFR Sup
Rnf.- *-N.Opticus. y
Rink. . "ee : ‘oe AES
N.Opticus.-“_- RnB.
a Gupe et ee ee
eR Ext _Eye Muscle Canal.
Obl. Sup., superior oblique; Obl. Inf., inferior oblique] O.S.X., rotatory slip
of superior oblique; R. Swp., superior rectus; FR. Inf., inferior rectus;
R. Int., internal rectus; R. Ext., external rectus; R.F'r., right frontal;
L.Fr., left frontal; R.P.Fr., right prefrontal; L.P.fr., left ‘prefrontal ;
M.E., mesethmoid; M.H1., anterior portion of mesethmoid; Vo., vomer ;
Pa.S., parasphenoid; Al.S., alisphenoid; Sp.O0., Sphenotic; f.olf., olfactory
foramen ; f.tr.fa., trigemino-facial foramen,
oA TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
recti, and are inserted into the superior posterior surfaces
of the eyes. These posterior slips are the rotatory slips of —
the superior oblique muscles, and their function* is to
cause a rotation of the eye on its optical axis, a movement
which is very exceptional among fishes as among higher
vertebrata, and which is doubtless a special adaptation to
the peculiar mode of life of the Pleuronectide. The
extent of the rotation may be as much as one-eighth of a
circle.
Inferior oblique muscles (0. 7nf.).—Both right and
left muscles originate in the left prefrontal in the same
region as that from which the superior muscles take
origin. The left muscle passes upwards and backwards
along the external wall of the orbit and is inserted into
the inferior middle surface of the eye-ball. The right
muscle takes origin a little in front of the left, and, as in
the case of the superior muscles, the proximal portions
eross each other. It then passes through the ethmoidal
fenestra with the superior muscle of its side, and passes
upwards and backwards along the external wall of the
right orbit, and is inserted in a corresponding position to
that of the left eye. The inferior are slightly thicker than
the superior muscles.
The superior recti (7. swp.).—These are strong muscle
bundles originating in a strong oblique partition crossing
the eye muscle canal. They run forwards in the latter,
slowly diverging from each other, and emerge on either
side of the interorbital septum. They are inserted into
the superior and posterior margins of the eye-balls under-
neath the rotatory slips of the superior oblique muscles.
The inferior recti (7. inf.).—Also rather thick muscles
which take origin far back in the eye-muscle canal at
about the transverse level of the articulation of the head
* Bishop Harman—Journ. Anat. Phys., vol. xxxv., pp. 1-40, 1899,
SEA-FISHERIES LABORATORY. 325
of the hyomandibular, on the internal surface of the
parasphenoid. They emerge from the canal into the
deeper parts of the orbits and are inserted into the eye-
balls on the inferior and middle surfaces, just underneath
the insertion of the inferior obliques, so that their
extremities are hidden by those of the latter muscles.
The internal recti (7. int.) Not so strongly developed
as either inferior or superior recti. They originate near
the place of origin of the superior recti on the partition in
the eye-muscle canal referred to. They run forwards in
the orbit close to the interorbital septum, and are inserted
into the eye-balls on the anterior and internal surface
underneath the extremities of the superior obliques.
The external recti (r. evt.)—These are the most
slender of all the eye muscles. They take origin on the
internal surface of the parasphenoid far back in the eye-
muscle canal, and leave the latter above and externally.
They are inserted into the external and posterior surfaces
of the eye-ball. A large portion of the distal extremity of
each is tendinous, and contains little contractile tissue.
With regard to the Bulbus oculi itself, we have only
space to mention the more striking features in its
anatomy.
Blood vessels.—The afierent vessels of the bulb are
(1) the ophthalmic artery, the origin of which has been
already described, and (2) a small vessel springing from
the circulus cephalicus between the origins of the internal
carotid arteries. The efferent vessel is the superior
jugular vein which begins its course in the eye. ‘These
vessels lie in the eye-muscle canal. They emerge from
the latter accompanied by the optic nerve of their side
with which they are bound up by a common sheath of con-
nective tissue. -Arrived at the eye all three perforate the
896 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
sclerotic. The ophthalmic artery breaks up in the choroid
gland. The other artery appears to pass forwards with
the optic nerve to the retina, but we are uncertain as to its
precise distribution.
The sclerotic consists of two layers, an external layer
of tough fibrous tissue into which the eye muscles are
inserted, and an internal cartilaginous layer of some thick-
ness. The cartilaginous sclerotic is perforated for the
entrance of the optic nerve and the blood vessels, the
fibrous layer becoming continuous with the connective
tissue surrounding the latter structures. The cartilaginous
sclerotic ceases at some distance from the pupil, and the
fibrous layer with another layer which seems to be a con-
tinuation forwards of part of the choroid fuse with the
skin of the head to form the cornea. In suitably prepared
sections all these layers can be distinguished in the cornea,
and the structure of the skin in that region does not differ
materially from that in other parts of the head.
The Argentea.—Internal to the sclerotic and in close
contact with its internal surface is the peculiar layer so
named. It covers the whole internal surface of the
sclerotic as far forwards as the iris. It has a white silvery
appearance by reflected light, but is opaque to trans-
mitted light. No structure beyond wavy bundles of very
fine fibres can be made out in it. The silvery appearance
is said to be due to minute crystals imbedded in a cellular
tissue.
The Choroid.—This is the usual vascular and pig-
mented layer. It lies between the argentea and the
retina, is closely adherent to the latter, and comes away
with it when removed. Anteriorly it passes into the iris.
The Choroid Gland.—This structure is situated in the
posterior wall of the bulb between the argentea and the
choroid. It lies to the nasal side of the entrance of the
a
ee eS ee
SEHA-FISHERIES LABORATORY. BT
optic nerve, is elongated in the longitudinal axis of the
body, and curves round the nerve so that its concave
margin faces the temporal side of the eye. It is not a
gland sensu stricto, but a rete mirabile. The ophthalmic
artery on entering the bulb immediately breaks up into a
number of short capillaries which run transversely to the
long axis of the gland; at the lateral margin these turn
backwards on themselves, and open into a very prominent
vein which traverses the whole length of the gland. From
this vein a very short transverse trunk pierces the sclerotic
and forms outside the bulb the distal extremity of the
superior jugular vein. We are unaware of any plausible
hypothesis as to the function of this organ.
The Retina presents no features of special interest.
The radiation outwards of the fibres of the optic nerve
towards its periphery is very striking. A prominent black
line runs outwards from the place of entrance of the optic
nerve to the temporal margin of the retina. This is the
choroidal fissure, which here divides the retina, and by
exposing the pigmented choroid beneath shews as a black
line.
The Processus Falciformis and Campanula Halleri.—
A delicate fold of the choroid projects through the
choroidal fissure into the vitreous humour. This is the
processus falciformis. Its distal extremity is swollen out
into a bilobed pear-shaped enlargement—the Campanula
Halleri, which is attached to the lens. ‘These structures
are said to form an accommodation apparatus. Accom-
modation in the fish eye is effected not by an alteration in
the curvature of the lens but by its approximation to the
retina through the contraction of the muscular tissue in
the above campanula and processus. ‘The elasticity of the
suspensory ligament increases the distance between lens
and retina.
328 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
Discussion of the Asymmetry.
We have now ascertained the facts which justify a
fuller discussion of the causes and course of the asymmetry
of the head. To satisfactorily understand the considera-
tions which we put forward, the reader will find it essen-
tial to follow our argument with dried crania both of a
Plaice and Cod before him. We have already described
the cranium in detail, but it will be useful to summarize
those features relevant to the present discussion.
| Note then that (a), the bony interorbital septum is
formed by the right frontal alone, that it is a thin flattened
bone lying in the morphological horizontal plane of the
head, and that in front it is in contact with the ethmoid
cartilage which is perforated by a wide fenestra; (B), that
the left prefrontal has lost its primitive connection with
the left frontal* but is still attached to the parasphenoid
bar, while the right prefrontal, though still in contact
with the right frontal has lost its connection with the
parasphenoid bar, and is further distinctly anterior to the
left bone ; (c) that all the oblique muscles take origin from
the left prefrontal.
Note now the differences between these relationships
and those of the corresponding structures in the Cod’s
skull. In the latter (4), the fused frontals form a broad
root to the cranium, and internally and below two bony
ridges form the bony portion of the interorbital septum,
whilst the ethmoid cartilage is not perforated; (B), the
right and left prefrontals are in contact with the frontals
of their own side and with the parasphenoid bar; (c), the
oblique muscles take origin from the upper portion of a
strong membranous partition joining the frontal ridges
* The present connection between the left frontal and left pen is
purely secondary, as mentioned elsewhere.
SEA-FISHERIES LABORATORY. 329
with the ethmoidal cartilage, and practically they arise
from the lower portions of the median frontal ridges.
Now if we suppose that the asymmetrical skull of the
Plaice first began to appear in an ancestral form
resembling the Cod, grave difficulties at once arise. For
if a rotation from left to right of the orbital region of such
a cranium took place, it is evident that although the left
eye might ultimately look upwards, the right on the other
hand must also move and would tend to become buried
in the tissues of the head. Moreover it is probable that if
a round fish such as the Cod adopted sedentary habits on
the sea bottom, the flattening, if it occurred at all, would
be a dorso-ventral one, as in the case of the skate.
But if we assume that a laterally compressed fish (like
Zeus, for instance) took to a bottom habit, and began to
he on one side of its body, the changes necessary to bring
about such asymmetry as we find in the Plaice would be
much less violent. In such a form we may suppose that,
following the lateral compression of the body, the eyes
would-have moved to near the dorsal edge of the head,
whilst the frontals would have become greatly compressed
from side to side and probably elongated dorso-ventrally,
like the right frontal of the Plaice. The eyes therefore
being now close together near the dorsal median hne of
the head, require to travel so much the lesser distance.
Now when such a fish assumed a bottom living habit,
lying on (say) the left side of its body, any variations in ~
the position of the left eye bringing it nearer the middle
line than the right (7.e., nearer the upper side) would be
of great advantage. This approximation to the middle
line would be attained either by the attenuation of the left
frontal or by a shifting of both frontals towards the right
side. In the skull of the Plaice both these things have
happened.
330 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
It is very remarkable that comparatively slight
changes would have sufficed to bring about the distortion
of the Plaice’s skull starting with such conditions and
tendencies as we have indicated above. In the head of
the Plaice the orbital region only has suffered extensive
change. The otic region has undergone practically no
change, and the prefrontal region certainly less than the
orbital. The jaw apparatus is not affected at all by the
torsion of the orbit, but has an asymmetry of its own (as
described above), and this latter doubtless explains the
asymmetry of the prefrontal region, which is of a different
character to that of the orbital. We have, therefore, now
to consider whether such relationships in the anatomy of
the skull and eyes as obtain in the Plaice can be reason-
ably expected to have followed from such a course of
evolution as we have sketched above. There appear to us
to be four difficulties requiring explanation. These are
as follows :—
(1.) The relations of the two prefrontals. As the
right frontal bent over further to the right side, the right
eye would be forced downwards. To make room for it
the parasphenoid bar most probably bent over to the left
to the position in which we now actually find it. The pre-
frontal region lagged behind in this shifting, being
unaffected except as regards the movements of the adja-
cent parts (orbital region and jaw apparatus). If a Cod’s
skull be examined it will be seen that the abortion of the
left frontal would result in the separation of the left
prefrontal from the remainder of the frontal area, and
further that the greater rotation of the frontal over the
prefrontal area would result ecther in the separation of the
right prefrontal from the right frontal, or in its separation
from the parasphenoid bar.. Now the latter having itself
rotated to the left, we therefore find that in the Plaice
SEA-FISHERIES LABORATORY. bol
the right prefrontal retained its connection with the right
frontal, but lost its connection with the parasphenoid bar.
After the rotation of the orbital region the left. prefrontal
grew backwards and the left frontal forwards, so as to
form the secondary junction of these two bones already
referred to.
(2.) The downward shifting of the oblique eye
muscles from practically the frontal to the parasphenoid
bar. ‘This possibly began in the symmetrical but laterally
flattened ancestor, as the frontals became attenuated from
side to side and deepened dorso-ventrally. But it was
continued in the asymmetrical fish. The object of the
shifting of the eyes was to make dorsal vision possible
with both eyes. In the Cod the origins of the oblique
muscles are best adapted for lateral vision and for visual
axes in approximately the same straight line. In the
Plaice, however, the visual axes are directed dorsally, and
to bring this about the oblique muscles had to shift
ventrally so as to exercise a more effective pull over the
eyes. ‘The origins of these muscles therefore moved down-
wards towards the ventral region of the cranium and
ultimately to the parasphenoid bar.
(5.) The attachment of all the oblique muscles to the
left prefrontal. We have already pointed out that the
right prefrontal has lost its connection with the
parasphenoid bar. This would doubtless have occurred in
the earlier stages of the rotation of the eyes. When,
therefore, in the final stages of the torsion, the oblique
muscles in their downward passage over the interorbital
septum arrived at the bar, the right prefrontal must have
already left it. They thereupon continued their migra-
tion on to the left side and became attached to the left
prefrontal—the only convenient attachment remaining.
(4.) The passage of the right oblique muscles through
332 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
the ethmoid fenestra. Primitively these muscles did not
pass through a fenestra. In the Cod’s cranium this does
not exist, but there is a cartilaginous wall in front of the
origin of the oblique muscles. In the migration ventrally
of the origins of these muscles the latter passed behind
_ and across to the left of the ethmoid cartilage to reach the
left prefrontal. The former. then grew up behind and
over the muscles, thus forming the fenestra.
We have not studied the anatomy of the head in
other Pleuronectids, and are unable to say whether the
relations of the eye muscles above described are general.
Cunningham (op. cit.) has described those relations in the
sole, and it appears that they differ considerably from
those we find in the Plaice. In the sole “the superior
oblique of the ventral |right| eye arises from the small
left [right is evidently meant] ectethmoid which is on the
right edge of the interorbital septum; the inferior oblique
arises from the external surface of the parasphenoid below
the right ectethmoid. But both oblique muscles of the
left or dorsal eye arise from the inner surface of the left
ectethmoid.” Owing to this disposition the direction of
the oblique muscles of the left eye is at right-angles to
that of those of the right, and this difference has resulted
from a rotation of the left ectethmoid.
The asymmetry of the sole was produced according to
Cunningham by the constant contraction of the oblique
muscles of the left eye, so as to * turn the pupil into a
horizontal direction and look along the edge of the head.”
The eye thus pressed on the interorbital septum, and led
' to the absorption and distortion of the latter. At the
same time the fulerum of this pull (the left ectethmoid)
has itself undergone considerable rotation “so that the
surface of attachment [of the oblique muscles] which
originally looked outwards to the left came to look upwards.”
SEA-FISHERIES LABORATORY. 330.
In the absence of figures we find it difficult to follow
Cunningham’s explanation, and we also find it difficult
to believe that the same mechanical strain—that of the
oblique muscles between the left ectethmoid and the left
optic bulb—could have, at the same time, (1) rotated the
bulb, (2) pressed on the interorbital septum so as to bend
that over to the right, and (3) rotated the ectethmoid
through a right angle. And we regard it as unjustifiable
to: base such a mechanical explanation on the attachments
of the muscles 7m an already asymmetrical skull. Tt is
inconceivable that the oblique muscles were attached in
the immediate symimetrical ancestor of the sole in the
same way that they are now. In the Cod, for example, we
find them arising symmetrically from the interorbital
septum, and therefore any discussion of the possibility of
those muscles producing distortion of the head should be
based on the conditions present in an unmodified
symmetrical cranium.
But whatever the conditions are in the sole we find
that in the Plaice Cunningham’s hypothesis is an impos-
sible one. Unlike the sole, all the oblique muscles are
attached to the left prefrontal (=Cunningham’s left
ectethmoid), and the latter we regard as the least altered
element in the orbitai or preorbital regions. That the
surface to which the oblique muscles are attached now
looks upwards we regard as more simply explained by
supposing that the upper portion of the left prefrontal like
most of the left frontal, with which it was most probably
suturally attached, suffered abortion in the shifting of the
left eye. And the shifting of the origins of the oblique
muscles to it has been a result of, or has been concomi-
tantly brought about by, the approximation of the eyes,
and the increasing tendency to dorsal vision,
334 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
4.—Tne Har (Fig. 24).
The auditory nerve is described with the other
cranial nerves.
As in Teleosts generally the ear is only externally
enclosed by the ear ossicles. Hence it projects freely into
the skull cavity internally, and is only separated from the
brain by its own and the brain membranes.
The utricular sac consists of a central chamber (utr.,
often divided into three portions, two of which constitute
the utriculus sensu stricto and the third the posterior
utricular sinus), and a wide ventral chamber or superior
utricular sinus or canal commissure (uwtr.'). These, how-
ever, may conveniently be called the central and vertical
chambers of the utriculus. From the anterior end of the
central chamber connections are effected with the ampullze
of the anterior and external semicircular canals, at the
posterior end with the ampulla of the posterior semi-
circular canal and the other extremity of the external
canal. The vertical chamber rises up almost at right-
angles from about the centre of the central chamber, and
receives above the upper extremities of the anterior and
posterior semicircular canals. There is only one sense
organ in the utriculus, the macula acustica recessus
utriculi (m. r. w.), situated in a slight depression of the
central chamber in front (Recessus utriculi). The three
semicircular canals are disposed as follows :—
Canalis anterior (a. s. c.).—Just above its connection
with the central chamber of the utriculus it swells into a
large ampulla anterior (amp. a.), the outer wall of which
bears a transversely extending sense organ and ridge, the
crista acustica ampulle anterioris (ant. er.). Above, the
canal passes upwards and backwards into the vertical
utricular chamber.
Se eS a a a ee
SEA-FISHERIES LABORATORY. DOD
Canalis externus (ec. s. c¢.).—Sometimes called the
horizontal semicircular canal to distinguish it from the
other two vertical canals. Swells into the ampulla
externa (amp. e.) immediately behind its connection with
the utriculus in front, The crista acustica ampulle
externe (eat. cr.) is situated on the floor of the ampulla
behind, but in front it ascends upwards and outwards, so
as to invade its external wall. The canal passes hori-
zontally downwards and backwards, external to the rest of
the ear, to communicate with the utriculus behind.
Canalis posterior (p. s. ¢.).—The large ampulla pos-
terior (amp. p.) occupies a similar position to that of the
anterior canal. Its outer wall contains a transverse sense
organ and ridge, the crista acustica ampulle posterioris
(post. cr.). Above, the canal passes upwards and forwards
into the vertical utricular chamber.
The Sacculus (sac.) appears at first to be an absolutely
closed bag in the Plaice, closely opposed to the utriculus
below, but having no. connection with it. Irom its inner
wall it sends upwards, however, a blind finger shaped
process which must represent a vestigial ductus endo-
lymphaticus (d. end.). There is no saccus endolymphati-
cus. Into the base of the ductus there open two very
minute capillary tubes (see figure), and as each arises
from, and communicates with, the utriculus, they must
together represent the canalis utriculo-saccularis. There
is thus only a very slight communication between the
sacculus and utriculus, and this of a very curious nature.
The sacculus contains the large hard saccular otolith
deposited in concentric lamine (oto.), and often called the
otolith.* There is, however, a small but quite conspicuous
* See Reibisch, Wiss. Meeresuntersuch, Abth. Kiel, N.I’., Bd. iv., p.
233 for an interesting discussion of the relation of the otolith to the age of
the fish. Reibisch finds that it is possible to deduce the age of a Plaice
from the conformations of the otolith.
333 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
otolith in connection with the macula acustica recessus
utriculi, and another with the papilla acustica lagene, but
none were observed in relation to the three cristz acustice,
although it is possible that small concretions of chalk
were there also. ‘There is a very large sense organ on the
inner wall of the sacculus in front, known as the macula
acustica sacculi (m. a. s.), and behind, the sacculus is pro-
longed upwards and backwards into the digitiform lagena
(/ag.), otherwise known as the recessus sacculi or cochlea,
the inner wall of which, at about the roof, contains another
sense organ, the papilla acustica lagene (p. a. 1.). soil
constriction or definite sacculo-cochlear canal is not
differentiated.
The sense organ on the floor of the utriculus known
as the macula acustica neglecta is entirely wanting in the
Plaice.
The ear and auditory nerve of Pleuronectes flesus have
been described by G. Retzius,t who, with other authors,
refers to the utricular, saccular and lagenar otoliths
respectively as the lapillus, sagitta, and asteriscus. His
description agrees very closely with ours of the Plaice, so
that it is only necessary to poimt out that he did not
succeed in finding either a reduced ductus endolymphati-
cus or a utriculo-saccular connection. With regard to the
latter he says:—‘ An der unteren Wand des Utriculus,
ungefahr gerade unter dem Sinus superior, findet sich eine
kleine, trichterférmige, hohle Verlangerung des Utriculus,
welche nach hinten geht und sich zu einer feinen Diite
verschmilernd an die Wand des Utriculus legt; ob aber
dieser Canal blind endigt, was ich am meisten glaube,
oder ob er vielleicht in den Sacculus (als ein Canalis
communicans) ausmiindet, kann ich nicht mit Bestimmt-
heit angeben.”’
+ Anat. Unters., 1872, p. 52, Taf. v., figs. 10O—18.
SEA-FISHERIES LABORATORY. oan
G.—THE REPRODUCTIVE ORGANS.
Some difficulty will be experienced in determining
the anatomy of the reproductive organs, on account of the
fact that sexual maturity does not occur until the Plaice
has grown to a relatively large size, and that to examine
the varying relations of the system in a really satisfactory
manner fishes in various phases of reproductive activity
must be examined. The ordinary marketable Plaice is as
a general rule an immature fish. There is some consider-
able difference in the size and age at which it becomes
sexually mature in different localities, but it will be suffi-
cient for our present purpose to say that under 17 inches
of total body length in the female, and 14 inches in the
male, the reproductive organs are generally immature. Only
fishes of those sizes should therefore be dissected for these
organs, and they are best examined some little time prior to
the spawning season, that is daring November to January.
We may here define several terms used in the follow-
ing pages. The Plaice is spoken of as “ mature’ when it
first begins to produce eggs capable of fertilization, or, in
the male, functional spermatozoa. It is “ripe’’ when the
ovary becomes distended with mature ova, that is imme-
diately before the spawning season. It is “spent” or
“shotten’’ when all the ova have been extruded in the
act of spawning. ‘The same terms with the same signifi-
cance are applied to the various phases of the male in
respect to the conditions of the testes.
Considerable differences in the condition of the repro-
ductive organs may then be expected in Plaice of different
sizes or of mature fishes captured at different times in the
year. In the female fish of about 14 inches long ovaries
and ovarian eggs are certainly developed, but the organs
are represented by very minute structures situated in the
AA
338 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
posterior wall of the body cavity. At this age, and for
some considerable time afterwards, it is quite impossible
to distinguish between male and female gonads without a
microscopical examination. The growth of ovaries or
testes is extremely slow during the first two years of life,
that is up to 6-8 inches long. After this age the ovary
can be readily distinguished from the testis. It is a
paired conical shaped structure. The base just projects
into the posterior part of the body cavity; the apex pro-
jects backwards towards the tail, lying between the
haemal spines and the muscles of the trunk. The oviducts
are extremely difficult to dissect and do not open exter-
nally. In the follawing year the organ rapidly develops.
In male Plaice of the same size the testes are paired
ridges of the posterior body wall projecting forwards into
the body cavity, but having no extension backwards as in
the case of the ovaries. |
The Female organs. —Fig. 20 represents the condition
of the ovary in a mature and nearly ripe Plaice. The
specimen figured was captured in December. ‘The ovary
is seen to project far forward into the body cavity, dis-
placing various organs from their normal positions. Part
of the posterior extension of the organ is indicated in the
figure ; it really extends backwards to near the root of the
tail. Its posterior portion lies along the external surface
of the haemal spines. and is only separated from these by
loose areolar tissue. ‘The overlying muscles of the trunk
are very thin, and occasionally the ovary appears to be
covered only by integument and connective tissue. In
this condition it can be felt externally as a hard pad lying
on either side of the ventral portion of the body behind
the anus. The ovary of the ocular side appears to be,
sometimes at least, more strongly developed than that of
the eyeless side..
SEA-FISHERIES LABORATORY. 339
On spawning a very marked change takes place.
Fig. 21 represents the condition of a mature and spent
female. The ovary is seen to be considerably retracted,
and is only just visible on opening the body cavity. Its
walls are soft and flaccid, and enclose a large cavity. The
posterior extension still exists, and is indeed not much
shorter than in the ripe specimen. The condition of the
fish is indicated externally by a shallow groove running
backwards on either side in the position formerly occupied
by the pad spoken of above. The flesh is lean, and the
fish is generally regarded as in poor condition as a food.
It appears* that after spawning the ovary never
reverts to its former immature condition. That is, it is
always possible to distinguish between a spent mature,
and an immature fish. Similar contrasts are exhibited
by the various phases of the testes, but on account of the
relatively small volume of these organs the changes are
not so striking and afford no external indications.
The ovary of the Plaice, like that of the majority of
Teleostean fishes is a sac the wall of which is continuous
with that of the oviduct. ‘This is the cystoarian condition,
and for an understanding of the morphology of such an
ovary the other common type met with among Teleostei,
the elasmoarian ovary, must be studied.t The internal
wall of the cystoarian ovary corresponds to the external
face of the peritoneal lamella which forms the elasmoarian
organ, and to the outer visible surface of the ovary of an
Elasmobranch fish—the surface from which the ova
dehisce into the general body cavity. There can be no
doubt from the work of Balfour and Parker{ on Lepi-
dosteus, that the cavity of the cystoarian ovary into which
* See Holt, Journ. Mar. Biol. Ass., vol. ii., p. 363.
+ See Howes—Hermaphrodite genitalia of the codfish. Jour. Linn.
Soc., London, vol. xxiii., 1891, pp. 539-557.
{ Structure and development of Lepidostews, Phil, Trans., vol. clxxiii.,
Part 2, 1882.
340 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
the ova dehisce is a closed portion of the celom. The
cavity of the oviduct is also a portion of the celom. It
does not appear to be a Miillerian duct like the oviduct of
all other vertebrata, and its morphology is exceedingly
obscure. It has no homologue among the genital struc-
tures of the male fish. The external opening of the oviduct
(Od., fig. 20, pl. V.) lies just within the lip of the anus on
the posterior side of the latter. It may appear to be out-
side the anus on the ventral body wall, and its variable
situation is due to the extent to which the terminal por-
tion of the rectum is contracted. In the immature fish
the opening does not apparently exist, and even in the
mature but unripe individual we have been unable to
satisfy ourselves of its existence. If in a ripe female
Plaice the body over the region of the ovaries be gently
pressed, the mature eggs issue in a thick stream, and the
opening can then be easily seen as a transverse slit behind
the anus. After extrusion of all the eggs this slit seems
to close up by the adhesion of its edges, and in dissecting
such a spent specimen, though the terminal part of the
oviduct can be traced to just behind the anus, some little
pressure with a blunt seeker is required to force a passage.
In the nearly ripe fish which has not yet spawned even a
moderate pressure on the abdomen may not cause the
extrusion of any eggs, though dissection may shew that
mature ova are present in considerable number lying loose
in the cavity of the ovary. The more nearly ripe the fish
is, the more easily are the eggs expelled, until in some
cases merely lifting it from the water in which it is lymg
may cause the eggs to run from it. There is generally no
bleeding from the edges of the forced opening in a nearly
ripe fish, and sections of the region of the body wall
behind the anus shew that it is formed almost entirely of
dense fibrous connective tissue without many blood
SEA-FISHERIES LABORATORY. 341
vessels. It appears to be the case that the efferent portion
of the oviduct opens before each spawning, and closes again
- by adhesion of its walls when the act of spawning is over.
The external oviducal opening leads into a short
chamber (Od.') into which both right and left ovaries open.
Od." is the cavity of the right organ. The septum in the
figure is the fused internal walls of both ovaries. All this
terminal chamber in the ripe fish is filled up with ova
which have dehisced from the ovigerous lamella. On the
internal walls of the ovary are the ovigerous lamelle,
longitudinal folds of the wall in which the ova are
developed. ‘Text-fig. 3 represents part of a transverse
section of the ovarian wall in a spent fish and shews a
single ovigerous lamella. In this condition the wall is
thick. Externally there is a loose connective tissue layer,
and in the thickness of this a thin sheet of black pigment.
Internal to this layer is an investment of unstriated
muscle fibres of some thickness in the spent ovary, but
very thin in the ripe condition. Within this, and filling
up the thickness of the lamella, is a somewhat dense con-
nective tissue stroma. The surface of the lamella is
formed by an epithelium which in places has a rather
_obseure structure, but here and there contains patches of
small rounded cells, obviously a germinal epithelium.
From this the ova proliferate into the thickness of the
lamella, and come to lie freely in the stroma, at first near
the surface of the former. Many such ova of different
sizes are represented in the section. ‘he largest have a
distinct zona radiata, the nucleus is large with a distinct
nuclear membrane and with diffused chromatin. An
obvious ring of large spherical nucleoli is seen in contact
with the nuclear membrane. Often the nucleus is con-
tracted away from the membrane, leaving a clear space.
The Male organs.— The testes are undivided flattened
342. TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
masses lying one on each side of the Ist axonost on the
posterior wall of the body cavity. They are indistinctly
lobulated, but not follicular as in the Cod and so many
other Teleosts. They are much smaller than the ovaries
in the female and project forwards only a little way into
the body cavity. There is no posterior extension beyond
the limits of the latter at any phase in the spawning cycle.
They are tubular glands, but the walls of the seminiferous
tubules are closely opposed and there is little or no con-
nective tissue between them. The whole organ appears
therefore as if divided up by a system of irregular
trabeculz in the meshes of which are massed the sperma-
tozoa.
Towards the ventral and anterior extremity of the
testes the volume of the organ rapidly diminishes, and if
traced in serial sections the number of tubules becomes
much less. Finally three or four such run forwards on
each side laterally and dorsally to the terminal portion of
the ureter. These unite, and a single duct on each side
runs alongside the latter and opens into its terminal
portion quite near the urinary papilla. The terminal
portion of the ureter is therefore a urinogenital sinus. If
the abdomen of a male fish when near the spawning season
be gently pressed, the seminal fluid issues from this
papilla. In the female it is a urinary papilla only, in the
male a urinogenital papilla.
SEA-FISHERIES LABORATORY. 343
APPENDIX—ECONOMIC.
A.—Lirr-History anp Hastts.
Spawning.—About the beginning of the year the
reproductive organs of mature Plaice become ripe and
spawning commences. Spawning—that is the complete
extrusion of the contained ripe ova and spermatozoa, lasts
over a considerable period on any one fishing ground.
This is due to the fact that it requires some time for any
one fish to extrude all its ova, and also to the considerable
variation in the time of ripening of the reproductive
organs among all the mature fish present on the spawning
‘
eround. ‘The duration of this “‘ spawning season ”’ varies
in the seas round the British Islands. In the Danish seas
it begins in November, attains a maximum in January
and February, and ends in April. In the North Sea on
the Scottish side it lasts from the middle of January till
the end of May, with the maximum at the beginning of
March. In Loch Fyne in the Firth of Clyde in 1898 no
Plaice eggs were found till the middle of February and .
none aiter June; the maximum number was found in
April. In the Irish Sea the exact limits of the season
have not been determined, but certainly it begins later
than in the North Sea. The maximum period as deter-
mined by the abundance of ripe female fish is at the end
of March.
From one quarter to half a millon eggs are extruded
by a single female Plaice during its spawning season, the
average number on the various fishing grounds being
about 300,000. This number of eggs is small when com-
pared with that of many other flat and round fishes.
Generally the larger the fish the greater the number of
eggs yielded. It is evident that during the spawning
344 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. —
season an immense number of egg’s must be present in the
seas round the spawning grounds, and this has been
approximately determined in various places. In a series
of remarkable researches on the quantitative estimation of
planktonic organisms Hensen* has made an approximate
determination of the floating fish eggs in various seas.
In the North Sea in 1895 he found during three voyages
an average number of 56°8209 Plaice eggs per square
metre of the track of the vessel. From the known area of
the North Sea (647,623 millions of square metres) Hensen
determined the total number of Plaice eggs in that area to
be 31°117 billions. It is evident that this number can
only be approximately accurate, but there are reasons for
believing that it really underestimates the total quantity.
In much the same way, Williamsont determined the total
quantity of Plaice eggs present in Loch Fyne during the
first eight months of 1898, and found a total number of
483 millions to be present in the loch during that time.
The Egg is one of the largest of those belonging to
Pleuronectid fishes, and is on that account easily recog-
nised in plankton collections. Its transverse diameter
varies from 1°63 to 2.11 mm. It is enclosed in a fairly
tough capsule, the outer surface of which is finely
corrugated ; at one place, beneath which the germinal disc
forms, there is a minute opening in the capsule—the
micropyle. ‘There is no oil globule, and the contents of
the egg are of a glassy transparency and apparently
homogeneous. A small perivitelline space is present
between the yolk mass and the capsule.
Before ripening the ovary of the Plaice contains only
opaque eggs considerably smaller than those extruded
* Hensen u. Apstein—Wiss. Meeresuntersuch., Kiel Commission, Bd. 2 —
(NB) Elett'2,. pi FL, 1897.
+ 17th An. Report Scottish Fish. Bd., p. 79, 1898.
SEA-FISHERIES LABORATORY. 345
after ripening. In the final stage of maturation before
spawning occurs these small opaque eggs acquire the
characters of the ripe pelagic egg.* The nucleus breaks
down and the chromatic matter becomes rearranged, and
at the same time fluid of a low specific gravity, secreted by
the follicular epithelium enters. As a result of this 1m-
bibition of fluid the yolk becomes altered in such a way
as to become nearly perfectly transparent. At the same
time the egg becomes larger and its specific gravity
becomes less. The immature ovarian egg has a mean
diameter of 1°2lmm. and a mean volume of 0°9276 cub.
mm. It is heavier than sea water. The mature egg has
a mean diameter of 1‘88mm. and a mean volume of 3°479
cub. mm. It is very slightly lighter than normal sea
water. The change in specific gravity during maturation
is from about 1'07 in the immature to about 1°025 in the
mature egg. Changes of this nature are general in the
maturation of nearly all Teleostean food fishes, and as a
result the eggs are pelagic—that is they float freely near
the surface of the sea when extruded. In the eggs belong-
ing to the other type—the demersal egg, of which the egg
of the herring is the most familiar example—the specific
gravity is greater than that of normal sea-water. As a
result of this the eggs undergo their development lying on
the sea bottom. |
The Plaice takes about two weeks to extrude the
whole contents of its ovary. Obviously in the limited
space at the disposal of that organ ripening of all the
eggs present would be impossible without injury to the
fish. Spawning is therefore intermittent during the
season of the fish, only comparatively few eggs being dis-
charged at one time. As the latter mature they dehisce
from the walls of the ovigerous lamelle and accumulate
* Fulton—16th An. Report Scottish Fish. Bd., Pt. iii., p. 88, 1897.
346 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
in the cavities of ovaries and oviducts, and are expelled at
intervals until the whole organs are exhausted. The fish
is then said to be “ spent.”
Fertilization takes place in the surrounding sea water
into which the eggs are extruded. During the spawning
season males and females are crowded together on the
spawning grounds, and the spermatozoa of the former are
shed simultaneously with the eggs. It is impossible to
say what proportion of the eggs extruded escape fertiliza-
tion. Probably it is very small, since unfertilized eggs
are not often seen in plankton collections. Fertilized and
unfertilized eggs would both rise towards the surface, but
in the course of a few days the unfertilized egg becomes
opaque, heavier, and finally sinks to the bottom and
decomposes.
Embryonic Development.—The period occupied by
embryonic development varies with the temperature of the
water in which the eggs are contained. The lower the
temperature the longer is the period between fertilization
and hatching. H. Dannevig* found that at 5°2°C. 21 days
were required; at 6°, 184 days; at 10° 12 days; and at
12° 103 days. Among Pleuronectide there is a general
correspondence between the size of the egg and the
developmental period. Thus the Flounder (Pl. flesus)
with an egg of 0°95mm. in diameter hatches out in 43
days at 10°C. At the same temperature the Sole (Solea
vulgarts), which has an egg of 14mm. in diameter, re-
quires 10, and the Plaice, with an egg of 1'8mm., 12 days.
The changes in the ovum immediately succeeding
fertilization have not been closely studied by any author.
The spermatozoon enters the egg through the micropyle;
at this time segregation of the protoplasm takes place,
and the latter which had previously been diffused round
*13th An. Report Scottish Fish. Bd., Pt. iii., p. 147, 1894.
SEA-FISHERIES LABORATORY. 347
the periphery of the yolk mass now collects into a lenticu-
lar mass—the germinal disc. When the egg is floating
freely, the germinal disc lies downwards, the yolk being
uppermost. This lower part of the egg has been termed
a9
the “animal pole,” the upper part the “ vegetative pole.”
A few hours after fertilization meroblastic segmentation
begins, by the formation of a single vertical furrow which
divides the germinal disc into two blastomeres. ‘This is
followed soon by a second furrow transverse to the first
and four equal blastomeres are formed. Up to the 8-celled
stage at least there are no horizontal segmentation planes.
After this stage both vertical and horizontal division
planes occur and the germinal disc segments with increas-
ing irregularity until it becomes a many-layered mass of
small cells. The blastoderm is thus formed.
The rim of the blastoderm now begins to grow out-
wards and to envelop the yolk mass by a process of
epibolic gastrulation. Towards the end of the 2nd dayt
it has extended over the yolk so as to cover about 70° of
the latter when seen in optical section. The growing
margin of the blastoderm is slightly thickened. The
space enclosed within this blastodermic ring where the
yolk mass comes to the surface is the blastopore, and with
the growth of the blastoderm past the equator of the ovum
its area continually diminishes. At first it is circular in
form and then becomes oval. After 6-7 days from fer-
tilization it disappears entirely.
The embryo begins to be raised off on the 3rd day
after fertilization. It lies in such a position that the
extremity which becomes the posterior one is situated
against the edge of the blastopore. On the 4th day it has
lengthened out considerably. The notochord and neural
+ Development is supposed to be effected at a temperature of about
a.
348 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
axis are laid down, and the main divisions of the brain are
visible. The optic vesicles are formed but are not yet
invaginated, and no mesoblastic somites are as yet discern-
ible. The tail projects as a slight swelling into the
blastoporic area. Underneath the tail a small vesicle has
appeared, which increases in size with the waning of the
blastopore. This is Kupffer’s vesicle (fig. 32), a structure
characteristic of the Teleostean embryo. It hes immedi-
ately beneath the posterior extremity of the notochord,
and in close relation to a slight depression under the
thickened blastodermic rim beneath the tail protuberance
—the “prostoma.” Its cavity is bounded by a regular
layer of hypoblastic cells, or its dorsal wall is so formed,
and its ventral wall is formed by the yolk. In some
Teleosts it communicates with the exterior by a narrow
opening. It is the invagination cavity of the (masked)
Teleostean gastrula, and represents the archenteron. But
from its large size and persistence it is probably a func-
tional larval organ, and Sumner* has suggested that it
subserves the nutrition of the embryo by aiding in the
absorption of the yolk.
On the 5th day constriction of the optic vesicles from
the mid-brain is complete, and on the 6th they are
invaginated and the lenses are formed so as to lie in the
openings of the optic cups. About 18 pairs of somites are
now present. The trunk has elongated considerably and
the head and tail are now constricted off from the yolk
mass; 8 days after fertilization the auditory vesicles are
present, the heart is formed and is beating, and the
vitelline circulation is being laid down. ‘The tail has
increased considerably in length and about 30 somites
are present. On the 11th day rudiments of the pectoral
fin folds are present.
* Mem. New York Acad., vol. 11, 1900, pp. 47-83.
' SEA-FISHERIES LABORATORY. 349
Pigmentation of the embryo begins on the 9th day by
the formation of a row of yellow branching chromato-
phores on either side of the body; on succeeding days
these become very abundant and extend on to the head
and cover uniformly the trunk and tail. Black pigment
appears on the 13th day as a row of round chromatophores
on each side of the body. Later on these become abun-
dant and of a branching form. On the 14th day the eye
becomes pigmented, and has a greenish-golden sheen.
The little fish hatches out from the egg on the 17th
day. It (fig. 35) is about 6°5mm. in total length—a rela-
tively large size among newly hatched Pleuronectids. The
yolk sac is very large. A continuous broad fin runs along
dorsal and ventral margins of the body. and round the tail.
The notochord is straight at the tip, and only rudiments
of the pectoral fins are present. It is covered (except the
yolk sac) with bright canary-yellow chromatophores, and
branching black chromatophores are situated along either
side of the body. ‘The eyes are greenish-gold in colour.
The mouth is open; the gut is a nearly straight tube
slightly dilated at one part and terminating in the anus
at the posterior margin of the yolk sac. The csophagus
is open, but has an exceedingly contracted lumen, and
there is an extensive yolk sac circulation. A pronephros
as described above also exists. The urocyst is in connec-
tion with the hind gut, and does not open directly to the
exterior. The young fish is still perfectly symmetrical.
The larval period and metamorphosis.—The larval
period lasts from the time of hatching until the definitive
form and asymmetry of the adult has been acquired; that
is till about 6 weeks from hatching. For the first week
_ there is little change in the larva except that during that
time the yolk is being gradually absorbed, and at the end
of 8 days the yolk sac has disappeared. ‘he larva now
350 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
begins to feed. It is probable that it feeds before the
yolk has been entirely absorbed. The food is necessarily
small, consisting of diatoms and larval molluses. It
grows very slowly, and at the age of 25 days from hatching
is only about 78mm. in total length and about 1°6mm. in
height. After this the increase in height is relatively
greater than that in length. Larval crustacea now form
the principal food. ‘The tail, which has hitherto preserved
its embryonic homocercal character, now bends upwards
at the tip, and ventral to this upturned portion fin rays
begin to be formed (fig. 36).
Up to 30 days after hatching the larva has retained
its bilateral symmetry, and at this stage is precisely
similar in form to the ordinary symmetrical Teleostean
larva. The greater relative growth dorso-ventrally than
longitudinally indicates the beginning of the metamor-
phosis, and after the 30th day the left eye begins to move
dorsally and anteriorly. 40 days after hatching it appears
on the dorsal margin of the head just anterior to the right
eye. On the 45th day the left eye has attained its defini-
tive position on the apparent right side dorsal and anterior
to the right eye. The larva is about 134mm. long and
63mm. high. During the period in which the eyes are
rotating the young fish gradually acquires a new position
in swimming; the vertical plane of its body slopes more
and more from right to left as the eyes shift round so that
in swimming the plane passing through both eyes is
always horizontal. At the completion of metamorphosis
the whole symmetry of the head has been profoundly dis-
turbed, though that of the body remains as before, except
that the opening of the ureter has shifted from the median
ventral line to the right side. The horizontal swimming
plane of the whole body has been rotated through a right-
angle and the fish rests and swims on its morphological
SEA-FISHERIES LABORATORY. 351
left side. The pigmentation now gradually disappears
from the lower side.
The larve now feed almost entirely on Copepoda,
with which their stomachs are usually crowded; larval
Molluses and larval Crustacea are also eaten. After the
metamorphosis the food is changed, and the small fishes,
14 to 4 inches, feed largely on various Annelids such as
Nerers and Pectinarza, on small Crustacea such as Mysis,
and various Amphipods and small Crangons. Later on
the fish adopts its definitive food, which is mostly Mol-
lusea, the favourite forms being Cardwum, Tellina, Mactra,
Scrobicularia, Donaxz and Mytilus. The character of the
food changes little during the rest of its life.
~ Rate of growth.—A variable time is taken up by the
changes above described, which were observed in larvee
kept in aquaria. For instance, although the Plaice in
the Danish seas may spawn as early as November, no
larvee of 12mm. length are taken there till May. They
therefore require six months to pass through the meta-
morphosis. Two methods have been adopted for esti-
mating the rate of growth subsequent to the larval period.
The most obvious one is to keep a large number of young
fish in captivity in aquaria, and to observe for as long a
period as may be possible the changes in body length.
This method is evidently open to the grave objection that
the fishes live under artificial conditions, and these may
influence their rate of growth. The other method is to
fish often in water's which contain great numbers of’ Plaice
of different sizes, and to deduce the growth rate from the
erouping of the individuals of different lengths. When
this is done and the results of measurement of all the
fishes captured are tabulated, it is seen that those captured
at any one time may be arranged into several groups in
each of which the greater number are grouped round cer-
$52 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
tain typical lengths, and if such experiments are kept up
for some time an approximation to the rate of growth may
be arrived at.
Such experiments have been carried out both in this
country and in Denmark. Dannevig* found that on the
East Coast of Scotland the Plaice grows about three
inches in the year. The average size at the end of the
first year is 77°2mm., at the end of the second 156°7, and
at the end of the third year 233'lmm. The experiments
also show that it is during the warmer part of the year—
May to October—that growth takes place. During the
winter it is practically arrested.
The period following the metamorphosis of the fish
till the third or fourth year may be called the immature
stage. It is characterised by the undeveloped condition
of the reproductive organs, and by the gradual, outward
migration of the fish towards deep water. The ovaries
remain small and contain only small transparent ova.
At a variable size and age sexual maturity is indicated by
the gradual enlargement of the ovaries and testes and by
the occurrence in the former of eggs containing yolk.
After the first sexual maturity occurs the ovaries never
revert to their condition prior to maturity, and it is always
possible to distinguish a fish which has previously spawned.
Sexual maturity.—The size at which first-sexual
maturity occurs is variable within somewhat wide limits
in the seas round the British Isles, and as a knowledge of
this size is of considerable importance as a basis for
fisheries legislation, great pains have been taken to esti-
mate it for various localities. It may vary within very
wide limits—thus in Danish waters spawning female
Plaice of 7” in length have been exceptionally taken,
* On the rate of growth of the Plaice. 17th An. Rep. Scottish Fish.
Bd., p. 232, 1898.
SEA-FISHERIES LABORATORY. Oe
while in the North Sea immature female fish of 17” have
been observed. In the male sexual maturity is first
attained at a lesser size than in the female; in Danish
waters ripe males 7 inches long, and in the North Sea
9 inches occur. The most convenient size* for purposes
of legislation is that lowest size at which as many Plaice
are mature as immature. This is the average size of first
maturity, and it is of course lower in the male than in the
female. In the northern part of the North Sea the female
reaches maturity for the first time on the average at 154
inches, and the male at 124 inches. In the southern part
of the North Sea these sizes are 154 inches for the female
and 104 for the male. In the English Channel Cunning-
ham found that nearly all Plaice were mature at 15 inches,
and in the North Sea Holt found that at 17 inches nearly
all the fish observed were mature. In the Danish seas
much lower sizes than these have been estimated by
Petersen.t Thus the average sizes at which Plaice first
become mature are 10 inches in the Baltic, 11 inches in
the Lesser Belt and 12-13 inches in the Kattegat. In the
Irish Sea the smallest mature female observed was 13
inches in length, and the largest immature female 19
inches. The smallest mature male obtained was 10}
inches long, and the largest immature male 15 inches.
Sufficient fish have not been examined in this district to
enable satisfactory average sizes for the first maturity to
be established.
It is probable that the Plaice spawns every year after
sexual maturity is attained, but there is no certain
evidence on this point, nor is it known what are the yearly
increments of growth after the third year of life. In the
* See Kyle, 18th An. Rep. Scottish Fish. Bd., Pt. iii., p. 189, 1900, for
a discussion of this subject.
+ 4th Report of the Danish Biol. Station, 1894, p. 3.
BB
354 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
largest fish obtained the reproductive organs are still func-
tional. The maximum size for the North Sea seems to be
28 inches, for the Danish seas it is smaller, about 224
inches. When the Iceland Plaice fisheries were first
exploited, very large specimens—over 30 inches in some
cases—were obtained.
Migration and distribution.— Wherever the distribu-
tion in space of the Plaice has been attentively studied it
has been found that a very well marked segregation in
respect of the size of the fish exists. There is a close
correspondence between the size of the fish and the depth
of the water at the bottom of which it is found. The size
increases with the depth. The fish does not exist outside
the hundred fathom line, and indeed practically all the
fishing is carried on in seas varying from 20 to 50 fathoms
in depth.
Since only the larger individuals are functionally
reproductive, it follows that the Plaice spawns only in
deep water, and it is the case that the spawning grounds
are always situated at some distance from the shore.
These spawning grounds are usually very definitely
located in any district. Thus on the Hast coast of Scot-
land such areas occur in the North about 16 miles seaward
from Moray Firth, and further South off St. Andrews Bay
and the Firth of Forth. In the Danish seas the fish only
:pawns in the more open waters, such as in the eastern
parts of the Kattegat, in the Belts and in the Baltic. In
the Irish Sea the positions of some such spawning grounds
have also been determined, and one notable area lies Kast
from the South end of the Isle of Man in a depression
having an average depth of about 23 fathoms and sur-
rounded by water of 16-20 fathoms in depth. The bottom
consists of soft bluish-black mud with an abundant fauna.
Scrobicularia and Turritella are very abundant, and the
SEA-FISHERIES LABORATORY. ODD
Pennatulid Virgularia is also common and forms a con-
stant food of various Gadide. Many edible fishes
spawn here, Pleuronectids like the Plaice, Flounder and
Dab, and Gadoids such as the Cod, Haddock and Whiting.
During the spawning season ripe fish may always be taken
by trawling on the ground, and pelagic eggs in various
stages of development are found in plankton gatherings
made at the surface. Another spawning ground exists
further North, due Hast of the North end of the Isle of
Man. On the West side of the Isle of Man are grounds
due West of Dalby where other Pleuronectids, and
probably the Plaice also, spawn, and it is very probable,
though systematic surveys have not yet been made, that
similar spawning areas he further South out from the ©
Lancashire and Welsh coasts.
As we have already stated the Plaice emits its spawn
at the bottom of the sea and the eggs rise towards the
surface. Here their inshore migration begins. The
developing embryo while still within the egg capsule has
of course no power of movement of its own, and even after
it has hatched and is a pelagic organism its powers of
migration are extremely limited, so that its present move-
ments are determined entirely by the combined operation
of physical agents, waves, prevailing winds, tidal drift and
currents, and from a consideration of the working of these
factors the general course of the eggs and embryos from the
spawning grounds can be determined.
The general drift of small objects floating at or near
the surface of the sea has been studied in the Irish Sea by
observing the movements of weighted bottles designed to
drift partially or wholly submerged. ‘I'wo such series of
experiments have been made,* and their results shew that
the combined operation of the various agents indicated
*TLancashire Sea Fish. Laby. Reports, 1895, p. 12, and 1898, p. 30.
356 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
above is to carry small floating objects in an easterly and
northerly direction. Thus eggs and embryos floating at
the surface on the spawning ground to the South-east of
the Isle of Man will travel easterly with a slight drift to
the North to Morecambe Bay, the estuary of the Duddon
and to the Cumberland coast. It is also evident that the
young fish inhabiting the shallow waters further South,
that is in the Ribble and in Liverpool Bay and the Che-
shire coasts, must have originated elsewhere than in the
spawning grounds referred to. Mr. R. L. Ascroft informs
us that from his experience of the drift of floating
wreckage it is probable that fish spawning far South in
Cardigan Bay and off the Welsh coast generally produce
the young fish in the southern and central portions of the
Lancashire coast. Up to the present time the spawning
areas off the Welsh coast have not been investigated. _
This first pelagic stage of the young Plaice is the
period during which both embryonic development and
larval metamorphosis take place. Up to the time when
the rotation of the eyes is fairly in progress the young fish
swims freely in the upper layers of the sea, and during
that change it gradually sinks until, when metamorphosis
is completed, it finally settles on the bottom. It is gene-
rally agreed that the young Plaice during this change
cannot, or at least does not, inhabit the sea at any great
depth. It is probable therefore that should the larve
begin to sink while still in deep water their destruction
follows, and it seems essential that they should have nearly
completed their larval changes not earlier than the time
when they arrive at the shallow coastal waters. About 30
days after hatching the larve seek the bottom and this
gives a period of over 40 days for them to complete their
inshore drift from the spawning grounds.
During this drift inshore the embryos and larve are
SEA-FISHERIES LABORATORY. 357
naturally exposed to many dangers. ‘They are probably
eaten by many pelagic animals, though there is not much
published evidence on this point. In Loch Fyne, how-
ever, the floating fish eggs are closely associated with great
numbers of Copepoda, and this results in the eggs being
eaten by the herring in the search of the latter after Cope-
poda and other pelagic Crustacea, and pelagic fish eggs
have been found in the stomach of that fish. It is possible,
however, that physical events are at least as fruitful causes
of the destruction of floating eggs and larvee as predaceous
pelagic animals. The change from the pelagic to the
demersal mode of living, for instance, happening when the
larva is still in deep water. Remarkable conditions are
present in the Baltic. Petersen* has shown that young
Plaice (up to 2-3 inches in length) are entirely absent in
that sea, though spawning fish are abundant, and, as
Hensen has shown, fertilized eggs are there in enormous
abundance. ‘The low specific gravity of the water affords
the explanation. Ata specific gravity of 1°0140 (at 9°C.)
a great number of Plaice eggs sink to the bottom, and at
a specific gravity of 1:0120 (at 10°C.) all sink. The lowest
specific gravity at which the eggs can drift about without
any sinking is 1°0152 (at 9°8°), and if in their migration
_ they enter water of less than this density their destruction
follows. Now it happens according to Hensen that about
once every month there occurs such a low specific gravity
of the Baltic water that all the Plaice eggs sink. There is
of course a possibility that the eggs may go on developing
at the bottom, but this is unlikely. It is possible too that
a low salinity of the water may prejudicially affect the
processes of development, but this subject has not been
adequately investigated. It is possible also that Plaice
eges entering the estuaries on the Lancashire coast may
* Rep. Danish Biological Station, 1V., 1894, p. 27.
358 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
be destroyed in this way, but the variation in the salinity
of those waters has not been thoroughly investigated.
Wherever spawning grounds may be located in the
Trish Sea, it is hardly likely that a longer period than
40-45 days can elapse before the larva finds itself in suitable
conditions on shallow sandy shores.
The young Plaice now enters on its life in the
‘nursery ’ ground. Practically the whole of the Lanca-
shire and Cheshire coast consists of ground of this charac-
ter—flat, sandy shores with shallow water overlying.
There are, however, several localities to which in par-
ticular the term is applied; there is the whole of the
shallow water round the mouth of the Mersey, the whole
estuary of the Ribble; the ground out from Blackpool
known as the Blackpool closed ground, the whole of
Morecambe Bay and the estuary of the Duddon at the
boundary of Lancashire and Cumberland. On all these
‘grounds vast quantities of young and immature Plaice up
to fish of 2-3 years old are found. Very young Plaice and
other Pleuronectids appear on these shores during June
every year. ‘hey have as a rule completed their meta-
morphosis, though a few may generally be got with the
eyes in the course of rotation. ‘They are generally about
+ inch and less in length, but have assumed the perfect
form of the adult (fig. 37). They may be found in great
numbers in the shallow sandy pools left by the receding
tide, where very many are stranded and perish. By the
autumn these little fish have grown to about 2-3 inches
in length. They are then present in great numbers on the
banks or shallower waters of the nursery ground. In
winter they disappear to a great extent from these banks,
or at least are not taken in the shrimp trawl, and it is
probable that they either bury themselves in the sand
when the colder weather approaches (this is a common
SEA-FISHERIES LABORATORY. 359
thing with much older Plaice), or they migrate to the
deeper portions of the nursery ground such as the
channels. The latter seems to be the case with the Mersey
nursery. Great quantities of young Plaice are to be found
there on the sandbanks, where the water is shallowest,
during July, August and September, maximum quantities
being taken in the latter month. During the winter
months, however, comparatively few are found there, but
they are abundant in the channels where the water is
deeper. This local migration then goes on independently
of the larger movement. ‘The Plaice move from the
shallow water to the deeper as the colder months approach
and from the deeper water in the channels to the shallow
banks as the temperature rises.
The young Plaice on these nursery grounds form part
of an exceedingly abundant vertebrate and invertebrate
fauna. ‘They are associated with other Pleuronectid and
Gadoid fishes—the dab, flounder, sole and solenette (Solea
lutea), with occasionally young brill and turbot and the
whiting, haddock and cod. Young sprats (Clupea
sprattus), sand-eels (Ammodytes), Cottus, sting-fish
(Trachinus) and Centronotus are also found; all these with
the exceptions of the sting-fish, sprat and solenette are
young and immature fish. Of the Gadoid fish the whiting
are very abundant. ‘These are young fish, in their first
year probably, and generally not exceeding five inches in
length. The invertebrates are usually crabs (Portunus)
and star-fish (Astervas), and great numbers of shrimps
(Crangon). The crabs alone often form nearly half the
total bulk of the catch.
_ These young fish are continually being captured in
the shrimp trawl, which having a square mesh of } inch
side, retains them. We may quote one single catch to
give an idea of the bottom fauna of the Mersey nursery
360 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
ground associated with the Plaice during August. The
catch was taken by a shrimp trawl the length of the mouth
of which was 25 feet and with a mesh of 4 inch side. It
was dragged for one hour over two miles of ground in six
fathoms of water. The bottom was a mixture of sand and
mud; the contents of the net were—
Soles, 257; 11 were over 8 inches long, 4 of the catch
were 2”-8”, the remainder 2”.
Plaice, 265; 6 were over 8”; remainder 2-8”.
Dabs, 896; 2 were over 8”, remainder 2”-4”.
Skates, 18; 7” broad across pectoral fins.
Whiting, 285; 5” long.
Shrimps, 20 quarts (a quart contains from 200 to 400
animals).
In addition to these about 200 Solenettes were caught,
many other fishes (Z'rachinus, Ammodytes, Clupea
sprattus) and a great number of Crabs.
On the Blackpool Closed Grounds in the central part
of the Lancashire shores even larger catches of young
Plaice have been made. Thus in 4 drags with a shrimp
trawl on—
September 25, 1893, for a drag of 24 miles, 3,302 plaice were caught.
December 28, 1893, ri oy AL oO OA ORT Aes Pr
January 2, 1894, sy oot Hee sbge bo eres i
February 14, 1894, tg ey TES age reese ep a oe
Over 10,000 young Plaice, of 2’-4” mostly, being caught in
these four drags alone.
In the various nurseries the fauna associated with the
Plaice varies somewhat, but in all shrimps are always
found where young Plaice and other Pleuronectids occur.
With increasing size the immature Plaice move out
from the nurseries into deeper water. ‘This off-shore
migration has been studied in an ingenious way by.
ea So —_—
SEA-FISHERIES LABORATORY. 261
Fulton* on the East coast of Scotland. Spawning takes
place on the off-shore grounds out from the mouths of the
Forth and St. Andrews Bay, and the eggs are borne
inwards and supply the nurseries in those waters. Num-
bers of Plaice on these inshore grounds were captured and
marked by the attachment of a numbered label, and then
liberated. After variable periods these fishes were re-
captured, generally by the fishermen, and then returned
to the Fishery Board officers. In this way the course
after liberation was determined, and it was found that a
slow migration from the South and round the North coasts
of the Firth of Forth and then round Fife Ness into St.
Andrews Bay took place, the fishes then moving outwards
from these shallow waters to the spawning grounds. It is
certain that some such movement takes place on the Lan-
cashire coasts, though Fulton's experiments have not been
repeated there. ‘The distribution of sizes is, however,
sufficient evidence, backed with what we know of the
actual movements in other places. We have seen that on
the nursery grounds great numbers of young Plaice of
about $ inch long are found during the early summer, and
owing to the great quantity of these small fishes the
average size at that time must be very low. ‘Towards
September, however, these little fishes have entirely dis-
appeared from the sandy pools, and the numbers of Plaice
on the grounds slightly off-shore (up to 6 fathoms in
depth) have greatly increased. ‘These fishes, which are
now from 2 to 4 inches in length, are the same individuals
which crowded the sandy pools between tide marks some
months earlier, and the first part of their off-shore migra-
tion has begun.
Further out to sea within territorial waters generally
the average size of the Plaice caught in the trawl nets is
* 11th An. Report Scottish Fish. Bd., p. 176, 1892.
—6B62 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
much greater. Probably about 9 inches will represent the
average size of the fish caught'in Morecambe Bay and
generally within the 3 miles limit. These fishes are now
marketable, and in suitable places all along the coast great
quantities at this size are caught in the stake nets. Larger
individuals are of course often got, but on these in-shore
fishing grounds mature Plaice are never or only very
exceptionally captured. It is these immature fishes which
in their gradual migration outwards form the mature
Plaice population of the more open sea. At or near the
spawning season they congregate on the spawning
grounds.
Briefly summarized then the migratory movements of
the Plaice are (1) the passive drift in-shore of the develop-
ing eggs and metamorphosing larve terminating as the
larva acquires the adult form and settles to the bottom,
and (2) the slow outward movement of the young fish,
deeper water being continually sought as it increases in
size. This movement ends as the fish becomes mature.
Thereafter its movements are probably very limited.
During the spawning season it probably does not travel at
all. With the extrusion of spawn another generation
begins the migratory cycle.*
* We have described only the larger migrations which are part of the
life movements of the Plaice. Smaller and local migratory movements
are of course continually going on. Mr. R. L. Ascroft informs us of a
curious instance which illustrates the connection between these smaller
movements and physical events. A severe storm about 1885 was followed
by a very marked increase in the numbers of Plaice in one of the channels
of the Ribble estuary—the Bog Hole. For about four days great
quantities were caught, one of the sailing trawlers getting as much as
180 score of fish (value £30) in a day. ‘The cause of this remarkable
abundance was that the storm and rough water washed off the ‘‘ Sand
pipes’? (Pectinaria belgica), which existed in great abundance on the
neighbouring banks, into the channel, and the Plaice followed the food.
edt ie —
*
2 1 i ee ee Se
SEA-FISHERIES LABORATORY. — 363
B.—Tue Puaice FIsuery.
We are able to present here only a very brief sketch
of the economy of the Plaice, and the reader who is suffi-
ciently interested in this direction is referred to the very
extensive literature which has now been published in
Britain, Germany and Denmark. We propose to deal
only with the methods in use for the capture of the Plaice,
and with the causes of the apparent decline in value of the
fishery, and the regulations which have been suggested for
the future welfare of the industry.
Round the British coasts the Plaice is fished for in
three ways. It is caught by spearing, by means of stake
nets and by trawling. Of these methods the latter is
incomparably the most important. Comparatively few
fish are caught by spearing, and this method is only pur-
sued in shallow waters and then to a very limited extent.
Stake-net fishing is much more important, and is carried
on at many parts of the coast on the foreshore between
tidemarks where conditions are suitable. The net is
about a yard in width and is of variable length. In
Lancashire waters it may not exceed 300 yards in length,
and it has a square mesh of either 6 or 7 inches in peri-
phery. It is stretched on a row of stakes driven into the
sand in a straight line, at right-angles to the direction of
the tidal flow. It may be provided with pockets. Fish
swimming with the tide are caught in the meshes and are
removed when the net is “fished” at low water. At sea
the Plaice is fished by means of the trawl. ‘The trawl net
is a conical bag of variable length. Its mouth is held
open by means of a wooden beam on which the net is
stretched, so that the open mouth is rectangular in shape.
At either end of the beam are fastened iron frames, the
“irons, the lower parts of which rest on the ground. ‘The
364 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
lower margin of the mouth of the net, that which rests on
the ground, is laced on to a stout rope—the “ foot rope,”
which is much longer than the beam and accordingly
drags behind the latter in a wide bight. From either iron
a strong rope proceeds—the “ bridles,’ the free ends of
which are fastened together by the “ shackle.” To the
shackle the trawl warp, either of rope or of steel strands, is
fastened. When fishing the whole contrivance is dragged
on the sea bottom, and after a variable time the net is
hauled on board the vessel, and the apex of the cone, the
“cod end,’ is untied, and the contents are allowed to
drop out on deck.
The dimensions of the trawl vary. In Lancashire
territorial waters (within 3 miles from low-water mark),
when the length of the beam does not exceed 18 feet, there
must not be less than 50 rectangular meshes in the cir-
cumference of the net, when it exceeds 18 and is less than
25 feet there must not be less than 60 meshes, and when
the beam exceeds 25 feet the net must contain not less
than 80 meshes. The mesh of the trawl net must measure
(with a certain exception) 7 inches at its periphery.
Within the territorial waters only sailing vessels may
trawl. Outside on the high seas there are of course no
regulations, and the trawl] may have any form and dimen-
sions desired. When employed by steam fishing vessels
the trawl beam may be as long as 50 feet, but the beam
trawl seldom exceeds those limits.
Since about 1896 the beam trawl has been largely
“ce
superseded in deep sea trawling vessels by the “ otter”
trawl. In this apparatus the general form of the beam
trawl is retained, but the beam is discarded, and its place
is taken by a strong rope, the ‘* head line,’ to which the
upper margin of the mouth of the net is laced. The foot
rope is the same as in the beam trawl but the head line
SEA-FISHERIES LABORATORY. 365
may be 120 feet lung. The mouth is kept open by being
attached to “otter boards,’ which are very large and
heavy wooden boards shed with iron, one edge of each of
which rests on the ground. They take the place of the
irons in the beam trawl. ‘They are set at an angle to the
direction in which the net is dragged, and by being
pressed outwards when pulled keep the net open. The
net is hauled by two warps, one of which is attached to
each otter board and passes in over one of the quarters of
the vessel. The otter trawl is stated to have an efficiency
37-50 per cent. over that of the beam trawl.
These are the two principal methods of fishing in
39
this country. In Denmark the “seine” net takes the
place of the trawl. The Danish Plaice seine is a bag of
netting about 20 feet long, the mouth of which is produced
out into two wings of about 180 feet in length. The depth
of the mouth and wings is about 7 feet. There are 5 or
6 meshes to the foot in the netting. The apparatus is
used from an anchored vessel by being “ shot” in a wide
curve at some distance from the vessel. It is then hauled
by two warps, one attached to each wing. The net drags
on the bottom in the same manner as the trawl. In
Denmark the fish are landed alive, a custom which is quite
exceptional in British fishing, the fish being brought to
the port of landing preserved in ice.
What the real value of the Plaice fishery in British
waters may be is difficult to determine accurately. The
official returns made by the Board of Trade collectors of
statistics show that for the year 1898, 35,788 tons of Plaice
having an initial value of £875,680 were landed at British
ports. Of this total quantity 31,544 tons were landed at
Kast coast ports, 2,355 tons on the South coast, and 1,882
tons on the West coast. It will be seen how important
the Kast coast Plaice fisheries are, those grounds yielding
366 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
over 88 per cent. of the whole, while the South coast yields
6 per cent. and the Irish Sea only 5 per cent. It is gene-
rally believed, however, that these official returns of the
Board of Trade are imperfectly collected, and the above
figures are to be regarded as minimum values. Accurate
returns of the numbers of fish landed at Grimsby in one
year alone are furnished by Holt.* For the year ending
March, 1894, over 17+ millions of fish were landed at that
port. Most of these fish were caught in the North Sea, a
small proportion only in Iceland waters.
We have seen that the Plaice, like other Pleuronectid
fishes, is a permanent bottom living fish, has a compara-
tively limited distribution, and a range of migration which
is relatively small. On account of these habits it is pecu-
larly liable to capture by present means of fishing, and
at no stage in its life history from the metamorphosis
onwards does it go outside the range of the fisherman’s
operations. While yet on the nurseries it is caught by
the shrimp trawler, on the inshore grounds it has become
marketable and is caught in the stake and trawl nets, and
in the open seas, when mature, it becomes the prey of the
deep sea trawler. In many of these respects it contrasts
with the commoner round fishes, such as the herring, cod
or mackerel. While it is generally agreed that the supply
of the last named fishes is practically inexhaustible, it
seems no less clear that the abundance of Plaice and other
flat fishes may be very sensibly influenced by the opera-
tions of modern fishing, and in fact many arguments point
to the conclusion that the flat fisheries on British coasts
are declining. The present system of collecting statistics
is, however, so incomplete that to make out an absolutely
convincing proof of this is difficult, and it is only fair to
* Holt—An Examination of the present state of the Grimsby Trawl
Fishery. Jour, Mar. Biol. Assoc., vol. iii, (N.S.), 1893-5, p. 339.
SEA-FISHERIES LABORATORY. 367
state that contrary opinions have been expressed. It is at
first sight a paradox that year by year the total catch of
fishes in British waters should increase, while the fishing
grounds may be really deteriorating. Along with this
increase in total quantity of fish caught, however, has
gone on a marked increase in the catching powers of the
fishing fleets and an extension of the area fished over.
The introduction of steam into fishing vessels about 1850,
and the use of ice for preserving the catches, made possible
the use of larger and more efficient apparatus (the otter
trawl latterly), and enabled the vessels to make longer
voyages. With this change the small sailing boats began
to decrease in numbers, and fishing instead of being car-
ried on by vessels independently owned by masters or
crews, became a great capitalised industry.
Therefore although the annual catch has gradually
increased, the average catch per vessel is now beginning
to decrease, and the density of the fish population in the
seas round the British Isles is less than it formerly was.
The catches of 4 Grimsby sailing trawlers for every year
since 1875 have been published by Garstang,* and all of
these shew a marked decrease with hardly any fluctuations.
In Danish seas the same decline has been noticed.
Petersent has shewn that there has been a steady decrease
in the size of the Plaice landed for many years, and it is
obvious that the reduction in size of the fish landed is
indicative of the reduction in number of those present on
the fishing ground.t
*See Garstang Mar. Biol. Assoc. Journ. for these figures and the
elaboration of the above argument.
+ 4th Rep. Danish Biological Station, 1893.
{ From the relation between the average size at first maturity and the
average size of all mature plaice captured, the change in the fish population
of an area may be deduced. See Kyle— 18th An. Rep. Scottish Fish, Bd.,
1900, p. 200,
368 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
It is worthy of note, however, that the decline in the
annual quantity of Plaice taken from the North Sea may
be regarded as the reduction of an ‘‘ accumulated stock” *
and not entirely as the diminution of the number of fish
annually coming to marketable size. At one time the
North Sea was practically a virgin ground, and the large
and numerous fish taken from it were a stock which had
accumulated for many years and which were rapidly
fished out.
Obviously the estimation of the fluctuations of the
fish population of a great fishing ground is a task of the
utmost difficulty. We may mention the quantitative
method of plankton investigation as one of the most pro-
mising means of dealing with this problem. This method
has been greatly developed during recent years by Hensen
and the German Fisheries investigators, and it is now
possible to make a rough estimation of the number of
pelagic fish eggs of any species such as the Plaice, in an
extended fishing ground. Only a rough approximation of
the eggs present can, of course, be made since many difh-
culties and sources of error are obviously to be considered.
But the Hensen method is as yet the only serious attempt
99
at a “‘ census of the sea’’ which has been attempted, and
it is possible that its refinement and thorough application
may go a long way towards solving the question of fisheries
impoverishment. We have stated that Hensen estimates
the number of Plaice eggs floating in the North Sea
during 1895 as about 31 billions. Now it is known that a
mature female Plaice produces annually about 300,000
eggs and it was then easy to calculate that about 103
millions of mature female Plaice were present in the
North Sea in that year. From the known ratio of the
* See Hjort and Dahl, Rep. on. Norwegian Fish. and Mar. Investigations,
yol, 14, nO. 1p. 151, 1900,
SEA-FISHERIES LABORATORY. 369
sexes the total number of mature fish can be further cal-
culated. Such determinations made from year to year
would obviously give the fluctuation of the adult Plaice
population.
Of all the Pleuronectid food fishes the Plaice is the
most important by reason of its relatively great abundance
and on that account when the probability of the decline of
the fishery became evident it was the object of much solici-
tude on the part of the fisheries authorities, and many
remedial measures have been proposed. In this country
the continual destruction of immature fish has been the
most obvious danger to the fishery, and the remedies have
all been directed to the minimising of this evil. The idea
underlying the remedies suggested has been to allow as
many fishes as possible the chance of spawning at least
once in their lifetime. This destruction of immature fish
takes place in every form of fishery. Practically all the
fish captured in inshore fishing, whether by trawl or stake
net, are immature. LHven in the deep sea Grimsby fishing
more than half the fish landed are immature. In 1894*
of the Plaice landed at that port 7 millions were mature
and 9 millions immature. Of the same quantity 9}
millions were over 13in. in length and 63 millions under.
At first sight therefore it might appear that the imposition
of a size limit below which it would be illegal to land the
fish would be an effectual remedy. If based on the size at
which sexual maturity first occurs this limit would vary
for different localities. It is obvious, however, that such
a regulation is impracticable, since the Plaice becomes a
marketable fish long before it becomes sexually mature.
The imposition of such a limit would close the inshore
grounds against plaice fishing altogether.
Other size limits have, however, been proposed, and
* Holt—loc. cit., p. 410.
CC
370 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
the adoption of some one will probably come in the future.
In 1892 a conference held under the auspices of the
National Sea Fisheries Protection Association proposed
10in. as the legal minimum size of marketable Plaice.
Following this, in 1893 a Select Committee of the House
of Commons recommended 8in. as the limit, being influ-
enced by the existing legal sizes in other countries. In
France the legal size of Plaice is 54in., in Belgium nearly
the same, and in Denmark it is 8in.
It is to be noted that the arguments as to the decline
of the Plaice fishery are generally founded on the total
weight of fish landed, not on the number of individuals,
and this has suggested the ingenious ‘“‘ growth-theory ” of
Petersen* for the betterment of the fishery. In Danish
waters the weight of a 10in. Plaice is less than 4lb., and
that of a 14in. fish is more than twice as much. Now if
in the time required for a Plaice to grow from 10 to 14
inches the total mortality on the fishery ground is such
as to reduce the number of individuals by one-half, the
total weight of fish will remain much the same as before.
But it is not likely that the mortality will be so great,
since the Plaice is singularly free from disease, and at the
sizes mentioned its enemies (predatory fishes) are few. It
follows then that by deferring their capture until they
have grown to 14in. in length a much greater weight of
fish will be brought to the market. The utility of a size
limit (the most profitable one to be determined by experi-
ence) is therefore apparent. Though fewer fish are caught
the fishing will become more profitable. The practica-
bility of such a measure is greater in Denmark than in
Britain. There fish are brought to the market alive and
instruments of capture are designed to that end. Small
fish taken can therefore be returned to the sea alive. Here,
* Petersen—loc. eit., p. 48.
el Ae ea Bak
SEA-FISHERIES LABORATORY. 3871
with large trawls, heavy catches and long drags, most fish
are dead when the net is hauled. The success of such a
measure would therefore depend to some extent on the
possibility of devising a mesh of such form and dimen-
sions as would capture only moderately large Plaice with-
out prejudice to the capture of other (round) fish trawled
for.
As far as inshore fishing is concerned the “ vitality ”’
experiments made by Mr. Dawsont for the Lancashire Sea
Fisheries Committee have shewn that with moderately
short drags (one or two hours) both with fish and shrimp
trawls a great proportion of Plaice (81 per cent.) recover
when taken from the contents of the net and placed in
running sea water. The relative catching powers of nets
with different sizes of meshes have also been ingeniously
illustrated by the same writer. An ordinary fish trawl of
20 feet beam and with a square mesh of 7in. periphery
was used. Round the catching portion of this net a
similar net but with a mesh of 44in. periphery was laced.
The combined net was dragged in the ordinary manner.
Fishes which passed through the inner wide meshed net
were retained in the outer one. In one such trial the
inner /in. net captured 41 Plaice of about 9 inches in
length, while the outer 4$in. net caught 349 Plaice of
about 54 inches in length which had passed through the
inner net. In another trial of this combination net the
Tin. net caught 142 Plaice 74-91 inches long, and the
outer 44in. net 390 fishes of 44 inches long. Correspond-
ing results were obtained with the other fishes captured.t
Petersen’s ‘‘ growth-theory,”’ it will be seen, proposes
to remedy the exhaustion of the Plaice fishery by raising
+ See Lancashire Sea Fish. Laby. Rep. for 1893, p. 23.
t See Holt—Journ. Mar. Biol. Ass., vol. iii., pp. 437-441, 1895, for a
discussion of the probable results of regulation of the trawl mesh,
SV TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
the size and with this the weight of fish landed. ‘The
author contends that there are already sufficient eggs and
fry in the seas, and that it is not useful to attempt to add
more. In this country the view has generally been that
the decline in the fishery can be remedied by increasing
the quantity of eggs or fry in the nurseries, either by
increasing the number of spawning fish by the imposition
of a minimum size limit or by artificial incubation, or by
protecting the very young fishes on the nursery grounds.
In the Irish Sea the nursery is also a shrimping ground,
and the only means of attaining the latter object is by
interference with the shrimp trawl fishery, for the results
of experimental shrimp trawling which we have quoted
above sufficiently demonstrate that enormous destruction
of Plaice fry necessarily accompanies shrimp trawling in
- most places where it is carried on. Various attempts have
been made by the Lancashire Sea Fisheries Committee to
obtain powers to legislate in this direction, and the area’
known as Blackpool Closed Ground is as yet the only fish-
ing ground where shrimp trawling is forbidden in the
interests of the young Plaice and soles which are reared
there. The amount of destruction of young Plaice which —
was due to shrimp trawling on that area will be seen from
a consideration of the figures we have quoted above.
The shrimping ground at the mouth of the river
Mersey is an area on which shrimp trawling is extensively
practised,* and where as we have seen great numbers of
young Plaice unfortunately congregate. Hxperimental
hauls with a shrimp trawl have been made for many years
by the officers of the committee on a portion of this area,
which the Committee recently unsuccessfully attempted
to close against trawling during July, August and
*See Lanc. Sea Fish. Lab. Report for 1900, p. 39, 1901, for a short
account of this fishing ground.
a
SEA-FISHERIES LABORATORY. 373
September of every year. As the result of 7 years’ experi-
mental fishing it was found that 567 young Plaice were
taken in an average haul with a shrimp trawl on this
ground in those months. Now during those 3 months 15
shrimp trawling boats on the average are fishing there
every day, each boat making 3 hauls per day on five
days per week, 2,925 hauls in all. Supposing each boat
to have made the average catch of 567 young Plaice, over
one and a half millions of young fishes would have been
caught on this area alone during the three months men-
tioned per year. It must be remembered that in the
fishing as ordinarily practised the great majority of these
are really destroyed.
The enormous destruction of young fishes due to this
method of fishing will be realised when we state that there
are altogether about 100 boats employed in shrimp trawl-
ing in the Mersey estuary, and the grounds seaward from
the river, and that the above calculation applies to only
15 of these frequenting a particular area for 3 months.
The Mersey is not the only district in which shrimp trawl-
ing is practised. Just as active fishing is carried on in the
Ribble estuary and in Morecambe Bay and in many parts
of the coast, ‘‘ cart-shanking "—an equally destructive
form of fishing, is practised. We believe we are under
the mark in stating that the yearly destruction of young
Plaice on the Lancashire and Cheshire coasts before the
closure of the Blackpool ground due to shrimp trawling
must be measured by the hundred million.
It is a regrettable circumstance that regulation with
a view to the protection of the young Plaice on the nursery
grounds must to some extent interfere with the prosecu-
tion of shrimp trawling, but it seems probable that the loss
incurred by the latter fishery would be more than com-
pensated by an increased number of Plaice on the fishing
374 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
grounds, and even if these were caught while still imma-
ture fishes frequenting territorial waters there would still
be a net gain. It is a question worthy of consideration
therefore whether, in the interests of the Plaice fishery,
some restrictive measures applied to methods of shrimp
fishing would not be of benefit to the whole fishing
industry.
We are referring here to the method of fishing for
shrimps with the shrimp trawl, which is a net of the
pattern of the larger fish trawl described above but with
a mesh of 2 inches in periphery. Other forms of shrimp
nets are used, particularly the “shank” net, which is a
net like a trawl but having the beam, foot rope and irons
replaced by a rectangular wooden frame. A further
improvement consists in attaching the lower edge of the
net, not to the lower bar which drags on the ground, but
to another bar, parallel to this but placed two or three
inches above it. When disturbed the shrimp jumps, and,
clearing the bar, enters the net, while the fish when dis-
turbed swims off close to the ground and may escape
through the space between the two bars. Experiments
have shewn that these two nets capture relatively less
fishes and more shrimps than the ordinary shrimp trawl.
We have yet to refer to the artificial incubation of
Plaice eggs as a means of recruiting a fishing area in
process of exhaustion by overfishing. So far this has only
been extensively practised in Scotland. Mature male and
female Plaice are captured some time before spawning
begins and are penned in a “ spawning pond.” Spawning
and fertilization take place in the pond as in the sea and
the fertilized eggs are collected daily and are put into
the “ hatching boxes.” Through these a constant stream
of sea water passes and they are kept in continual motion
to avoid the clustering of the eggs and the risk of insuffi-
SEA-FISHERIES LABORATORY. 375
cient aeration. The eggs develop in these boxes and the
larve after being retained for some time are taken out to
sea and “planted” in a suitable locality. It will be
obvious from what we have stated above with regard to
migrations that the larve must be set free in such a place
that the prevailing winds and tidal drift will carry them
to a nursery (which must be present in the area dealt with)
in which the conditions for further development are suit-
able and in such a time that the assumption of the
demersal habit will coincide with the arrival of the larve
on the nursery grounds. The ultimate aim of the hatch-
ing operations is to rear the larve through the period of
their metamorphosis under artificial conditions. It has,
however, been found extremely difficult to rear even a
small proportion through the period referred to since great
numbers die during the period immediately following the
absorption of the yolk sac. In practice, therefore, the
larvee are set free before this mortality has seriously com-
menced. The Scottish Fishery Board, in addition to their
utilitarian object of adding to the number of young fish
in the sea, have since 1897 been devoting attention to the
interesting experiment of placing some millions of fry
yearly in one limited area where they have reason to think
they may be able to test the result by periodic observations
on the young fish fauna. In the period between 1894 and
1899 inclusive the Board set free 136 millions of arti-
ficially hatched larve, and since 1897 these have been
planted in Loch Fyne, the area chosen for experiment.
The argument for the utility of sea fish hatching
rests to some extent on the hypothesis that the period
during which the fish are being dealt with in the hatchery
is that during which the mortality in nature is greatest.
Since, in the hatchery, the eggs ans larve are safe from
enemies or prejudicial changes in their physical surround-
376 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
ings, this mortality is avoided. It is most probable that
during their pelagic life the eggs and larve are destroyed
by being eaten by other animals or by physical changes,
but unfortunately we have as yet no idea of the proportion
of eggs or larvee so destroyed. Experience in the hatchery
shews that it 1s during the period between the absorption
of the yolk sac and the beginning of the metamorphosis
that the mortality is greatest. This critical period 1s
characterised by the change in the means of nutrition of
the larva, which having used up the food yolk, begins to
feed on planktonic organisms. If this mortality exists in
nature, and if it should become possible to avoid it in the
hatchery, then the gain would be very considerable, but
until it shall become possible to rear the greater portion
of the larve hatched through their metamorphosis all that
is gained in the hatchery is the immunity of the eggs and
larve and of the fishes in the spawning pond. From this
latter point of view—the immunity of the fish yielding the
eggs—the hatchery is to be regarded as a reserve of
spawners, and its function becomes the more valuable the
greater the reduction of the fish population in the area
dealt with. It is to be regarded as effecting the same end
as would be brought about by protection of mature fish on
the spawning grounds—protection which at present seems
impracticable, or protection of the fry caught in the course
of other fishing—protection also apparently impracticable.
We refer here to the treatment of restricted areas. Prob-
ably the effective treatment of such an area as the whole
North Sea by artificial hatching is at present impracti-
cable. The deficit which the hatchery would have to
make good is the assumed reduction of the mature Plaice
population, and this most probably takes place on a scale
which it would be difficult to approach by artificial opera-
{ions according to our present ideas and methods.
SEA-FISHERIES LABORATORY. 377
It has been suggested that much the same results
would be attained by the removal and fertilization of the
ripe eggs from Plaice caught in the course of commercial
fishing and the immediate return of these to the sea with-
out having undergone treatment in the hatchery. We do
not know whether this is practicable, and at any rate, the
number of ripe eggs in the ovary of a Plaice at any one
time is only a small proportion of the total number pre-
sent. This method of obtaining eggs for the hatchery has,
however, been adopted at times. The trawling vessels
have been boarded on the fishing grounds and ripe fish
stripped,’ the eggs fertilized and taken to
66
have been
the hatchery.
As we have seen the most striking fact in the life
history of the Plaice is its limited range of migration,
and this has suggested the possibility of recruiting a
limited fishing ground in process of exhaustion, by plant-
ing artificially hatched larve on it. The most economical
method of obtaining the eggs would be from fish caught
in the course of commercial fishing. Obviously the scale
on which the hatchery would most effectively work would
be determined by a knowledge of the annual reduction cf
the fish population by fishing operations.
378 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
EXPLANATION OF PILATES.
Reference Letters.
. cay.—Internal carotid arteries (the two outer ones).
. car’ —Exxternal carotid artery.
. Cm.—Coeliaco—mesenteric artery.
. coe.—Coeliac artery.
a a a
. ep.—Right epibranchial artery.
A.F'.—Anal fin.
Af. Br. 1—4.—First to fourth afferent branchial arteries.
A. gen.—Common genital artery.
A. gen’—Right genital artery.
A. hep.—Hepatic artery.
A. hy.—Hyoidean artery.
Al. S.—Alisphenoid.
amp. a.
amp. e, | 7Anterior, external, and posterior ampulle of the semicircular
Leese canals.
amp. p.
An.—Angular.
a. NOS. ) , : ,
-—Right and left anterior nostrils.;
a. NOs’! .|
ant. cr.—Crista acustica ampulle anterioris.
Ao. d.—Dorsal aorta.
A. @.—Oesophageal artery.
A. op.—Ophthalmic artery.
Ao. V.—Ventral aorta.
A. pe.—Pelvic artery.
Ar.—Articular.
A.R.—Accessory ribs or intermuscular bones, numbered from before back-
wards.
A.R.*—Tubercle on fourteenth and many of the succeeding vertebre,
representing probably a fused accessory rib.
a. 8. ¢.—Anterior semicircular canal.
A. scl.—Right and left subclavian arteries.
A. sp.—Splenic artery.
Aur.—Auricle.
Az,—Axonosts or interspinous bones, numbered from before backwards.
Ag.“ —Transverse ligament connecting axonost with skin. sb
Az.» —Triangular plug of cartilage occurring in the head of every
axonost.
A. Zy.—Anterior zygapophysis.
SEA-FISHERIES LABORATORY. _ 379
B. A.—Bulbus arteriosus.
B. Br. 1-4.—Basi-branchials 1 to 4.
Bda.—Bile duct.
B. O.—Basi-occipital.
Br. 1.—First holobranch. 1, the first visceral arch.
Br. R.—Branchiostegal rays, numbered from before backwards.
Bs.—Baseosts, numbered from before backwards.
C.—Centrum.
C27»
C. Br.4
C. #.—Facet on atlas for paroccipital condyle.
C. Fn.—Caudal fin.
C. Hy.—Cerato-hyal.
cil. b,—Ramus ciliaris brevis.
cil. g.—Ciliary ganglion.
cul. l.— Ramus ciliaris longus.
| ~Censto-anchis of the first and fourth branchial arches.
Cir. c.—Cireulus cephalicus.
Cl.—Clavicle.
Co.—Coracoid.
com. 1—vu..—RR. communicantes between the sympathetic and the first
seven spinal nerves.
com. v.i—R. communicans between the sympathetic and the N.
trigeminus.
Cr. C.—Cranial cavity.
d. 2—6.—Dorsal roots of the spinal nerves 2 to 6.
D.—Dentary.
d. b. .
a | —Dors roots of the first spinal nerve.
d. end.—Vestigial ductus endolymphaticus, with two minute utriculo-
saccular canals opening into its base.
D. F.—Dorsal fin.
E. Br.
E =. j | —tpibranchial of the first and fourth branchial arches.
Ef. Br. 1—4,—First to fourth efferent branchial arteries.
Ep. 1
Ep. 2 | ie and second epural bones.
Hp. Hy.—Epi-hyals.
Ep. O.—Hpiotic.
380 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
Ep. P.—Epiotic process of epiotic.
e. §. c.—External (horizontal) semicircular canal.
Eth.—Ethmoid cartilage.
Ex. O.-—Exoccipital.
ext. cr.—Crista acustica ampulle externe.
f. car.—Carotid foramen, transmitting the internal carotid artery.
f. gl.—Foramen of the N. glossopharyngeus.
f. jug.—-Jugular foramen, transmitting the superior (internal) jugular vein,
the ophthalmic artery and the T. hyomandibularis facialis.
F,. M.—Foramen magnum (occipital foramen).
f. olf. —Olfactory foramen in the pre-frontal by which the N. olfactorius
reaches the nasal chamber.
F'.R.—Fin rays.
F.R.«» —The two pieces forming a single fin ray.
F.R.< —Ligament connecting the two halves of the fin ray.
F.R.4—Ligament connecting one half of the fin ray with the baseost.
F.R.< —The right abductor muscle of the fin ray. The elevator and
depressor muscles do not appear in this section.
F’, Sp. N.—¥oramina for the spinal nerves.
F.. Sp. N.* —Foramina for the fourth spinal nerve.
f. tr. fa.—Trigemino-facial foramen, transmitting the vth and viith nerves
except the T. hyomandibularis facialis.
f. vg.—Foramen of the N. vagus.
3—6.—Ganglia of the spinal nerves 3 to 6.
. v—vii.—Massed ganglia of the trigeminal and facial nerves.
. 1x.—Ganglion of the N. glossopharyngeus.
x. 1.—Ganglion of the first branchial trunk of the N. vagus.
x. 2—5.—Ganglionic complex formed by the second, third and fourth
branchial + the intestinal ganglia of the N. vagus.
~e 2 & &
. coel.—Ganglion coeliacum.
d. 2.—Dorsal ganglion of the second spinal nerve.
extcr.—Extracranial ganglion of the first spinal nerve.
. inter.—Intracranial ganglion of the first spinal nerve.
. v. 2.—Ventral ganglion of the second spinal nerve.
© 7 RAS
H. A.—Haemal arches, numbered from before backwards.
H. Br.1 —Hypo-branchial of the first branchial arch.
H. C.—Haemal canal.
H. Hy.—Hypo-hyals.
Hm.—Hyomandibular.
Hm. F.1-*—Cup and facet for head of hyomandibular. Cp. fig. 5.
SEA-FISHERIES LABORATORY. 381
HAp.}
Hp.2 |—First, second and third hypural bones.
Fip®
H. S.—Haemal spines, numbered from before backwards.
H. S.+—Last three haemal spines.
hy. c.—Hyomandibular sensory canal.
I. Cl.—*‘ Inter-clavicle.”
I. Hy.—Inter-hyal.
I. M. C.—Inter-maxillary cartilage.
In.—Innominate or pubic bone. The figures denote its three parts.
im. buc.—R. buccalis internus facialis.
inf. c.—Infraorbital sensory canal.
I. Op.—Inter-operculum.
I. Ph.—Inferior pharyngeal bones, representing a fifth pair of branchial
arches.
Jac. anast.—Jacobson’s anastomosis from the ninth to the seventh cranial
nerves.
Jug. g.—Jugular ganglion of the N. vagus.
lag.—Lagena.
lat. c.—Lateral sensory canal.
L. Fr.—Lett frontal.
l. g. x.—Ganglion of the R. lateralis vagi.
L. Le.—Left lachrymal.
LL. Na. C.—Position of left nasal chamber.
low. in. buc.—Lower division of the R. buccalis internus facialis.
L. P. C.—Left paroccipital condyle.
L. P. Fr.—ULeft pre-frontal.
L. rec. vin. : sate, :
a lateralis recurrens facialis and vagi.
lL. vec. x. )
man.v. | ; Ei ie haw ee
.. »~—R. mandibularis trigemini and facialis.
man. vir.
man. ext. vii.—R. mandibularis externus facialis.
man. int. vii.—R. mandibularis internus facialis.
m. a. 8.—Macula acustica sacculi.
M. C.—Pads of soft cartilage (fibrous in parts).
m. ad. op.—T wig from the N. trigeminus to the M. depressor operculi.
M. E.—Posterior portion of the mesethmoid bounding the orbit in front.
M. E..—Anterior portion of the same bearing the beak-like ridge for the
intermaxillary cartilage.
.
382 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
M. Pt.—Meta-pterygoid.
m. 7. U.—Macula acustica recessus utriculi.
Ms. Pi.—Meso-pterygoid.
Maz.—Maxilla.
mx. v.—R. maxillaris trigemini.
N.—Cup shaped cavity at each end of centrum containing vestiges of the
notochord.
N. A.—Neural arch.
Nc.—Notochord.
N. C.—Notochordal canal in centrum placing the notochordal spaces (J.)
in communication.
. ch.
nv. ch}
n. olf. -
n. olf
N. S.—Neural spines, numbered from before backwards.
N. S.t—Last three neural spines.
2. sac.1—*—The five right and left nasal sacs.
nm. sp.! )
n. sp.'! j
| Rie and left nasal chambers.
| Riek and left olfactory nerves.
—WNN. splanchnici.
O.C.—Occipital condyle.
Oc. S.—Occipital spine.
Od.—Opening of oviduct.
Od.‘—Common ovarial chamber.
Od.“—Interior of right ovary.
o. 1.—Branch of the N. oculomotorius to the inferior oblique muscle.
o. lam. )
-—Right and left series of olfactory lamine.
o. lam. |
Op.—Operculum.
Op. O.—Opisthotic.
o. pr.—Nervus ophthalmicus profundus (trigemini ?) and ganglion.
op. s. vii.—R. opercularis superficialis facialis.
0. s.—N. patheticus to superior oblique muscle.
oto.—Saccular otolith.
out. buc.—R. buccalis externus facialis.
Pa.— Palatine.
pal.—R. palatinus facialis.
p. a. l.—Papilla acustica lagen.
Pa. P.—Parotic process of pterotic and opisthotic.
SEA-FISHERIES LABORATORY. 383
Par.—Parietal.
Pa. S.—Parasphenoid.
P. Br.1 —Pharyngo-branchial of the first branchial arch articulating with
the skull.
P. Br.2-4—Pharyngo-branchials of the peanchial arches two to four, form-
ing the superior pharyngeal bone (S. Ph.).
P. C.—Paroccipital condyle.
P. Cl.—Post-clavicle.
Per.—Pericardium.
P. F.—Pectoral fin.
ph. x. 1
ph. 2,2.
ph. «. 3
Pl, F.—Pelvic fin.
Pl. F'.’—Base of right pelvic fin.
P. Mxz.—Premaxilla.
)_rr. pharyngei of the first, second and third branchial trunks of
| the vagus.
ee jig and left posterior nostrils.
p. nos.1
P. Op.—Pre-operculum.
post. 1
post. 2 —RR. post-trematici of the first, second, third, and fourth branchial
post. 8 | trunks of the vagus.
post. 4 }
post. vii.—R. post-trematicus facialis.
post. 1x.—R. post-trematicus glossopharyngei.
post. cr.—Crista acustica ampulle posterioris.
pre. 1. |
pre. 2. —RR. pre-trematici of the first, second, third and fourth
pre. 3. [ branchial trunks of the vagus.
pre. 4. |
Pr. O.—Prootic.
Ps. Br.—Pseudobranch.
p. &. ¢.—Posterior semicircular canal.
Pt.—Pterygoid.
Pt. O.—Pterotic.
P. Tp.—Post-temporal.
P. Zy.— Posterior zygapophysis.
Qu.—Quadrate.
r. v.—Root of N. trigeminus.
ry. 1. vii.—Dorsal (sensory) roots of N. facialis.
384 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
r. 2, vw.—Ventral (motor) root of N. facialis.
r. 1.—Root of N. glossopharyngeus.
r. 2.—Root of N. vagus sensu stricto.
R.—Ribs, numbered from before backwards.
r. @. @.—R. acusticus ampulle anterioris.
r. a. e.—R. acusticus ampulle externe.
r. a. p.—R. acusticus ampulle posterioris.
r. car. ?—R. cardiacus vagi ?
r. cerv.—R. cervicalis of the first spinal nerve (= ‘‘ N. hypoglossus.’’)
vr. com. 2—6.—RR. communicantes of spinal nerves 2 to 6.
7. com. b.—R. communicans of the first spinal nerve.
7. €.—N. abducens to external rectus.
Rec. Ax.1 —Longitudinal furrow on the anterior aspect of the first haemal
spine for the reception of the first axonost of the anal fin.
R. Fr.—Right frontal.
. hy.—R. hyoideus facialis.
. if. —Branch of N. oculomotorius to rectus inferior.
. test. x.—R. intestinalis vagi.
. 2t.—Branch of the N. oculomotorius to rectus internus.
1.—R. acusticus lagene.
. lat. «.—R. lateralis ‘‘ vagi.’’
. lat. x.’—Root of R. lateralis vagi.
r. lat. prof. «.—R. lateralis profundus vagi.
r. lat. sup. «.—R. lateralis superficialis vagi.
R. Lc.—Right lachrymal.
r. m. 2—5.—RR. medii of spinal nerves 2 to 5.
r.m. b. |
rT. M. C. j
R. Na.—Right nasal.
R. Na. C.—Position of right nasal chamber.
SS 2a RS eS
—RR. medii of the first spinal nerve.
r. op. «.—R. opercularis vagi.
vr. oph. sup. v.—R. ophthalmicus superficialis trigemini.
r. oph. sup. vii.—R. ophthalmicus superficialis facialis.
7. ot. —R. oticus facialis.
RR. P. Fr.—Right prefrontal.
r. 7. U.—R. acusticus recessus utriculi.
v. §.—Branch of N. oculomotorius to rectus superior.
r. sac.—R. acusticus sacculi.
r. sp. 2—5.—RR. spinosi of spinal nerves 2 to 5.
7. Sp- 0,
j—RR. spinosi of the first spinal nerve.
T.Sp,€.
———
7. 2
SEA-FISHERIES LABORATORY. 385
r. st. x.—R. supratemporalis vagi.
r, v. 1.—R. ventralis of the first spinal nerve + an anastomosis from the
second.
SE De ) E
Motor branches of the brachial plexus.
TD. 1.2 j
r. v. 1.3 —Motor
_ 1.4 —Sensory branches of the brachial plexus to the pectoral fin.
>
(S
vr, v. 2..—Anastomosis between RR. ventrales of the first two spinal
nerves.
2+ 3.—Fused RR. ventrales of spinal nerves 2 and 3.
2+-3.’—Motor branch sending an anastomosis to R. ventralis 4.
2+ 3”.—Sensory nerve to pectoral fin.
2—5,—RR. ventrales of spinal nerves 2 to 5.
~
Debate,
b-+-c.—R. ventralis of first spinal nerve.
rx. b,—Radix brevis.
rx. .—Radix longa ganglii ciliaris (accompanied by sympathetic).
sac.—Sacculus.
Sc.—Scapula.
S. C.—Spinal canal.
S. Cl.—Supra-clavicle.
Sin. V.—Sinus venosus.
Sk.—Outline of skull.
S. O.—Supra-occipital.
s. 0. c.—Supra-orbital commissure between the two supra-orbital sensory
canals.
S. Op.—Sub-operculum.
S. Ph.—Superior pharyngeal bone of the eyeless side intact. The numbers
denote the branchial arches to which its constituents belong.
Spl.—Spleen.
Sp. N.2—Thirteenth spinal nerve.
Sp. O.—Sphenotic.
S. R.—Strengthening ridges of the vertebral centra.
s. t. c.—Supratemporal portion of the lateral sensory canal.
sup. ¢c.—Right supraorbital sensory canal.
sup. ¢.
| vena of the left supraorbital sensory canal.
sup. c.”
Sy.—Symplectic.
t.
t. —-First, second and third Trunci branchiales vagi.
t,
Ses
WwW 2 &
DD
386 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
Tb. 1—5.—The five tuberosities seen externally on the ocular side passing
backwards from between the two eyes.
Thm.—Thymus gland.
t. hmv.—Truncus hyomandibularis facialis.
t. inf.—Truncus infraorbitalis (trigemini et facialis).
Tr. P.—Transverse process.
U. + Hp. 3.—Urostyle and third hypural fused together.
U. Hy.—Basi-hyal.
up. wm. buwe.—Upper division of the R. buccalis internus facialis.
Ur.—Urostyle.
Uret.—Ureter.
Ur. pp.—Urinary papilla.
uty.
- és ; | —centa and vertical chambers of the utriculus. .
2—6.—Ventral roots of spinal nerves 2 to 6.
V.—Vertebral centra numbered from before backwards. V! is the atlas.
v. b.!
v. b. }+—Ventral roots of the first spinal nerve.
V. C. j
V. card.—Cardinal vein.
Ven.—Ventricle.
V. gen.—Genital vein.
V. hep.—Hepatic vein.
V. jug. |
Vz jug.
Vo.—Vomer.
—Superior and inferior jugular veins.
Vp.—Portal veins.
V. pe.—Right precaval vein.
Prate I.
Vig. 1. Dorsal surface of an undried skull of a 65cm.
Plaice. Natural size. The dotted line indi-
cates the departure from the symmetry. The
anterior extremity is somewhat schematic,
and is drawn as if seen a little from behind.
The fenestra in the ethmoid cartilage is only
partially visible in a strictly dorsal view.
SKA-FISHERIES LABORATORY. 387
Fig. 2. Ventral surface of the same undried skull.
Natural size. The dotted line indicates the
swerve of the ventral axis of the cranium
towards the left side caused by the rotation
towards the right of the orbital region of the
eranium. The chondrocranium appears on
the surface of the cranium in several places,
and not always symmetrically.
Fig. 3. Lateral view of the same skull seen from the
right or ocular side. Natural size. The
right nasal and right lachrymal are here
fully shown, and do not appear in perspective
as in figs. 1 and 2.
Pruate LI.
Fig. 4. The occipital region of the same skull viewed
from behind. Natural size. The dotted line
indicates the departure from the symmetry.
The chondrocranium appears on the surface
between the exoccipitals and epioties.
Fig. 5. Lateral (moist) dissection of the opercular
bones, palato-pterygoid arcade, and jaw
apparatus of the Plaice, on the ocular or
right side. Natural size. Hxtreme length
of specimen J4cm. ‘The palatine has been
rotated downwards in order to illustrate its
shape, and the lower jaw has been depressed.
In the natural disposition of the parts the
lower end of the maxilla lies external to the
. mandible.
Fig. 6. Dorsal (moist) dissection of the Hyoid arch of a
34cm. Plaice. Natural size. In the living
animal the stout hyoid bar is almost vertical
and the basi-hyal projects forwards at right-
388
TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
angles from its upper border. ‘The lower
border of the bar in the figure is therefore
the dorsal border, and the face shown is the
anterior face. ‘The first pair of branchiostegal
rays has been turned forwards. ‘They really
pass straight backwards in the mid-ventral
line. The branchiostegal rays are numbered
from before backwards, and have been dis-
played. |
Fig. 7. Dorsal (moist) dissection of the branchial arches
of a 34cm. Plaice. Natural size. The arches
have been flattened out and displayed. On
the right side the three pharyngo-branchials
forming the superior pharyngeal bone have
been separated and left attached to their
respective arches, but on the left that bone
is represented intact drawn from its oral
surface. The arches are numbered from
before backwards (i.-v.).
Fig. 8. Lateral (moist) dissection of the right pectoral
girdle and fin of a 34cm. Plaice. Natural
size. The “ inter-clavicle ” in front is shown
in its correct position relative to that of the
pectoral girdle. The fin rays have been
separated from the two fibro-cartilaginous
pads with which they articulate.
Fig. 9. Lateral (moist) dissection of the right pelvic
girdle and fin of a 34cm. Plaice. Natural
size. The fin rays are represented dis-
articulated from the fibro-cartilaginous pad.
) Pare Ti
Fig. 10. First or atlas vertebra viewed from the front of
a 02cm. Plaice. Natural size. The acces-
—_— <2 = a’
Fig. 11.
Fig. 12.
Fig. 13.
Fig. 14.
Fig. 15.
SEA-FISHERIES LABORATORY. 889
sory ribs (intermuscular bones) have been
rotated forwards so that their exact length
may be indicated. The dotted line shows
the extent of the asymmetry.
The eighth trunk vertebra viewed from the
front of a 64cm. Plaice. Natural size. The
accessory ribs have been rotated forwards in
order to introduce their full length. The
dotted line shows the departure from the
symmetry.
The twelfth trunk vertebra of a 52cm. Plaice
seen in optical longitudinal section, the
ocular or right half of the centrum and right
neural arch having been ground away.
Natural size. The figure illustrates the
amphicoelous character of the centrum, and
the shape and extent of the notochordal
‘spaces.
The fourteenth or first caudal vertebra of a
62cm. Plaice seen from the front. Natural
size. The dotted line indicates the depar-
ture from the symmetry. The same ver-
tebra is shown in side view in fig. 18.
Moist dissection from right side of caudal fin
and termination of vertebral column of a
34cm. Plaice. Natural size. The fin rays
have been disarticulated from the fibro-
cartilaginous pad.
Dissection from right side of posterior extremity
of notochord and caudal fin supports of a
young Plaice or lfmm. Drawn with
camera. x 15. Notochord as yet unossified,
but faint vertebral constrictions (6 shown in
fig.) have appeared. The neural and haemal
390
TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
spines and epural and hypural bones are
beginning to ossify from without inwards.
The fig. should be compared with fig. 14. It
shows that the urostyle has not yet fused
with the third hypural, and that the caudal
fin of the young Plaice is of the ordinary
homocercal type.
Fig. 16. Longitudinal section through a fin ray and
Fig. 17.
Fig. 18.
axonost of the dorsal fin of a medium sized
adult Plaice, z.e., the section passing longi-
tudinally through the fin ray and transversely
to the long axis of the fish. Leitz 5, ocular
2. The figure shows the two pieces forming
one fin ray, and their relations and connec-
tions with the baseost and axonost. The
section does not pass through the plane of
the elevator and depressor muscles of the fin
ray, or the longitudinal vertical ligament of
the axonosts.
Prats FV.
Moist dissection from the eyeless or left side of
the anterior part of the dorsal fin and first
three trunk vertebre of a d2cm. Plaice.
Natural size. The outline of the skull is
introduced to show its ventral inclination
and its relation to the first eight-ten
axonosts of the dorsal fin. (Cp. table in
text.) The first three vertebre also have a
downward inclination.
Moist lateral dissection from the eyeless side of
the last four trunk and first three caudal
vertebrae, and of the anterior extremity of —
the anal fin and its supports of a 52cm. Plaice.
SEA-FISHERIES LABORATORY. ool
Two-thirds natural size. The ring at the
ventral extremity of axonost 1 indicates how
much of the latter protrudes freely from the
body wall in dead specimens. Cp. table in
text. 3
Fig. 19. Moist lateral dissection from the eyeless side of
the last seven caudal vertebree and the pos-
terior extremities of the dorsal and anal fins
and their supports of a 52cm. Plaice. Natural
size. The sigmoid curve of fin ray 71 of the
dorsal fin and its horizontal position are
abnormalities. Cp. with fig. 14 and table
in text. :
PuLatE V.
Fig. 20. The viscera seen from the ocular side. Only
the body wall has been removed and the
muscles of the limb girdles dissected away.
The ovary and rectum are opened to shew
the external opening of the oviduct. The
specimen was a ripe female. ‘Two-thirds
natural size.
Fig. 21. The viscera seen from the ocular side. The
body wall and the superficial coils of the ©
intestine have been removed and the pectoral
girdle, operculum, sub-operculum and inter-
operculum dissected away. ‘The lateral wall
of the pericardium has been removed. The
positions of haemal spine 1 and axonost 1
are indicated by broken lines. The speci-
men was a spent female. Two-thirds natural
size.
392 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
Pirate VI.
Fig. 22. Diagrammatic representation of the principal
blood vessels and their distribution. The
principal viscera are introduced into the
figure in order to shew the distribution of
the vessels only. Their space relations to
each other are not accurately shewn. The
intestine 1s represented for simplicity’s sake
as a single coil. The hepatic portal system
is not shewn, nor the distribution of the
carotid arteries. The arteries are cross
hatched, the veins are uniformly shaded.
About natural size.
Pruate VII.
Fig. 25. Reconstruction from serial sections of the
cranial nerves of the ocular side. The. two
scales in this and other figures refer to the
numbers of the sections. Sensory canals
coloured green. ‘Their sense organs and
surface pores are numbered in each canal
from before backwards. Eye muscle nerves
cross striated. The numerals refer to the
numbers of the cranial nerves. Note the
relatively large size of the eyes in the young
fish. The curve of the medulla shown in
this figure does not exist in the adult, and is
probably an abnormality.
Pruate VIII.
Fig. 24. Reconstruction of the left ear and auditory
nerve seen from the inner or left side. This
figure cannot be compared with fig. 25, the
reconstruction being made on a somewhat
SEA-FISHERIES LABORATORY. 393
larger scale, although from the same series
of sections. ‘he nerve ramuli in front are a
little diagrammatic, in order that they may
be shown more clearly. viu., auditory
nerve. ‘The reconstruction applies also to
the adult ear, but the relative sizes of the
parts are of course different.
Fig. 25. Reconstruction of the right and left nasal
‘organs seen from above. Drawn to exactly
twice the scale of figs. 23 and 26, and from
the same series of sections. The disposition
of the accessory secretory chambers is
slightly diagrammatic for the sake of clear-
ness. The termination of the olfactory
nerves is not shown for the same reason.
Fig. 26. The sympathetic nervous system seen from
above, and plotted from the same series of
sections and to the same scale as fig. 23.
The dotted line represents the median line
of the body continued straight forwards.
The figure is diagrammatic in four respects :
(1) the celac ganglion les directly under
ganglion 2; (2) the first cranial ganglion
hes immediately over the second on the
ocular side; (3) the ocular ciliary ganglion
lies over the third nerve; (4) the eyeless
ciliary ganglion is external to the oculo-
motorius. The cranial ganglia are numbered
1-8, the spinal 1/-7’. iii. is the Nervus
oculomotorius, after it has given off the
nerve to the M. rectus superior.
PruateE IX.
Fig. 27. Reconstruction from serial sections of the first
EE
394 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
six spinal nerves of the right side seen from
the lateral aspect. ‘The two crosses indicate
the position of the foramen magnum. The
cranial region is to the right of these, the
vertebral to the left. The reconstruction is
from the same series of sections as figures
23-26, but is not drawn to the same scale.
The formal shading of the ganglia is omitted
in the case of the first spinal for the sake of
clearness. The roots of most of the spinal
nerves lie internal to the ganglia and there-
fore cannot be shown. ‘Their places of
origin, however, are indicated by the oval
dotted areas. ¢
Fig. 28. Transverse section through the fore-brain to
illustrate the asymmetry of this part of the
brain. The dotted line indicates the mid-
vertical plane. Most of the brain therefore
here hes to the right. Note the fibres col-
lecting at the base of each bulbus olfactorius.
These ultimately form the olfactory nerves.
Drawn with the camera, Zeiss aa. oc.4.
PLATE X.
Fig. 29. Plaice split up the middle from below into two
halves and spread out to show both sides of
the sensory canal system. x #. The anterior
extremity of the dorsal fin is not shown.
The shading indicates the innervation of the
sensory canals. Swpraorbital canals, cross
hatched (R. ophthalmicus superficialis, vi.) ;
Infraorbital canals, dotted (R. buccalis,
vil.); | Hyomandibular canals, shaded (R.
mandibularis externus, vu.) ; Lateral canals,
SEA-FISHERIES LABORATORY. 3Y5
cross striated (R. lateralis, x.). The line of
dashes represents the suppressed portion of
the left supraorbital canal.
Fig. 30. Dorsal view of the brain of a Plaice having an
Fig.
Fig.
Fig.
dl.
eo:
4.
35.
extreme length of 58cm. x 3. The pallium
and the choroid roof of the fourth ventricle
have been removed, but the asymmetrical
position of the pineal tube and body is indi-
cated. ‘he dotted line shows the departure
from the symmetry. ‘he numbers are those
of the cranial nerves. |
Lateral view of the same brain with the pallium
in situ.x 3. Numbers as in preceding figure.
PuatE XI.
Embryo Plaice on the 5th day after fertilization
and before invagination of the optic vesicles.
x 29.
Embryo Plaice on the 9th day after fertiliza-
tion. The black spots on the body and tail
represent the yellow branching chromato-
phores which appear about this time. x 29.
Kmbryo Plaice on the 17th day after fertiliza-
tion. The embryo is ready to hatch. The
branching black markings on the body and
tail are the black chromatophores. The
yellow pigment is represented by the grey
spots. x29. Nat. size of this and the
preceding eggs = 1°88 mm.
Newly hatched Plaice, 17 days after fertiliza-
tion. The black pigment is represented by
the stellar markings, the yellow by the grey .
spew. x17, Nat. lenoth — 63 mim.
Figs. 32—35 are drawn from the living eggs
396 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
and larva from material treated at the Piel
Hatchery. The average temperature of the
water in the hatching boxes during the
developmental period was 7° C.
Fig. 36. Larval Plaice at the beginning of the metamor-
phosis. The yolk-sac has been absorbed, and
the larva is beginning to feed. Note the
beginning of the asymmetry—the left eye is
more dorsal than the right. Note also the
upturned end of the notochord. Nat. size
= 15mm. x6. (After Ehrenbaum, Hier
und Larven von Fischen der Deutschen
Bucht. Wiss. Meeresuntersuch. Kiel. Komm.
Bd. 2, Heft J., Abth. I., Plate 4, figayiss
1896.)
Fig. 37. First bottom stage of the Plaice. The
metamorphosis is completed. Note the
relatively large size of the eyes and the small
paired fins. x4}. Nat. length = 13 mm.
(After Petersen, 4th Rep. Danish Biological
Station. Pl. I., fig. 10. 1893.)
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397
ON SOME RED SEA AND INDIAN OCEAN
COPE PODA.
By Anprew Scort.
(With Plates I-III.)
[Read April 11th, 1902.]
Two collections of sub-tropical Copepoda made by (1)
Mr. H. C. Robinson and (2) Dr. H. Lyster Jameson, were
eiven to me for investigation during the past year (1901).
These collections, on examination, were found to contain
a number of interesting species of Copepoda, including
some forms apparently new to Science, and now described
and figured.
(1) Mr. Rosinson’s CoLiecrion.
The first and most extensive collection was forwarded
to me by Professor Herdman, F-R.S., my esteemed chief,
to whom I am much indebted for the opportunity of
examining what proved to be a profitable series of tow-
nettings. This collection was taken between Suez and
Colombo, by Mr. H. C. Robinson, in the latter part of
March, 1901, during his voyage out to Siam. It was com-
menced on March 21st, soon after the ship left Suez, and
completed on March 31st, shortly before Colombo was
reached. The collection represents roughly a continuous
section of the Copepoda, &c., living near the surface of the
sea between these two ports at that particular time of the
year. This collection was made by attaching a fine tow-
net to a tap in one of the bathrooms which was supplied
FF
898 TRANSACTIONS LIVERPOOL BIOLOGICAL: SOCIETY.
with sea water continuously pumped up from the sea by
the ship's pump. The water was allowed to strain through
the net day and night continuously throughout the period,
except on one or two occasions. The contents of the net
were taken out in the morning and evening of each day,
and preserved in separate bottles. Mr. Robinson’s collec-
tion was contained in twenty bottles, and represented ten
day and nine night gatherings. None of the gatherings
contained more than one c.c. of solid matter, whilst the
majority contained about half ac.c. only. Although the
gatherings were small in bulk, many of them were very
rich in number of species. As a rule there was a con-
siderable difference in the number of species of Copepoda
found in the gatherings taken during the day and those
taken during the night. The greatest number of species
found in any day gathering was thirty-three and the
lowest ten. On the other hand six out of the nine night
gatherings contained over thirty-three species; the
greatest number found in a night gathering was forty-two,
and the lowest twenty-one. The average number of
species for the ten days gatherings was slightly over nine-
teen and a half, and for the nine gatherings collected
during the night slightly over thirty-two and a half.
Day “238: 20, a SO a OR ees
oe 17 119" 30 (AO. AT) dG ss 1 TS eee
Wiss Suh i eh animate te wnts
21 38 36 36 37 22 25 36 42 species.
In addition to well-known oceanic Copepoda contained in
the gatherings, the following new species were observed :—
Candacia bradyi, Calanopia minor, Stenheliairrasa, Stenhelia
erythrea, Delavalia inopinata, Delavalia minuta, Laophonte
mornata, Laophonte herdman, Dactylopus robinsonu, Licho-
molgus minor, The total number of species of Copepoda
RED SEA AND INDIAN OCEAN COPEPODA. 399
observed in the Robinson collection was 86, belonging to
eight families, as under :—
Calanide - - - 15 species.
Centropagide - eo TO) €
Candaciide = - : : D i
Pontellide - - - 8 “a
Cyclopidz : = : 3 i
Harpacticide - - - 29 r,
Corycaeidee = - . - 9292 ¥3
Lichomolgide - - 1 $
The following list gives the period of time and date
when each gathering was made. The numbers 1 to 19
represent the different bottles, and will be used in referring
to the distribution of the species.
1. 9-15a.m. to 3-15 p.m.,and 3-15 p.m. to 5-45 p.m., 23.3.01. Com-
menced 13’ S. of Suez. Position of ship at noon 29°09'N.,
32°46'H. Sky clear, sea smooth. (Two bottles).
*2. 7-15 p.m., 21.3.01 to 6a.m., 22.3.01. Shadwan light at end of
Gulf of Suez passed about 9 p.m., dead calm.
3. 9-0 a.m. to 6-0 p.m., 22.38.01. Position of ship at noon 24°36’N.,
36°08’ E. Dead calm.
*4. 7-15 p.m., 22.3.01 to 6-20 a.m., 23.3.01. Slight N.N.E. breeze,
~ sea smooth.
5. 9-0a.m. to 5-45 p.m., 23.3.01. Position of shipat noon 19°53/N.,
39°08’EH. S.E. breeze, slight swell.
*6. 7-15 p.m., 23.3.01 to 6-10 a.m., 24.3.01. Strong S.E. breeze,
‘ sea moderate to rough.
7. 9-0 a.m. to 5-50 p.m., 24.3.01. Position of ship at noon 15°19’N.,
41°55/E. Strong S. breeze, heavy swell.
*8e 7-30 p.m., 24.3.01 to 6-15 a.m., 25.3.01. South breeze, moderate
swell. (40’ W. of Aden.)
*9, 7-15 p.m., 25.3.01 to 6-25 a.m., 26.38.01. Wind Hast, slight
swell. (40’ EK. of Aden.)
10. 9-15 a.m. to 6-0 p.m., 26.3.01. Position of ship at noon 12°24'N.,
49°24’'H. Wind Kast, sea calm.
*11. 6-0p.m., 26.3.01 to 6-10 a.m., 27.38.01. Wind Hast, slight swell.
12. 9-0a.m. to 6-0 p.m., 27.3.01. Position of ship at noon 11°33’N.,
54°53’EH., Wind Hast, nearly calm.
400 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
*13. 7-15 p.m., 27.38.01 to 6-10 a.m., 28.3.01. Wind East, sea calm.
14. 9-15 a.m. to 6-0 p.m., 28.3.01. Position of ship at noon 10°35‘N..,
60°22’E. Wind E.N.H., sea calm.
15. 9-0 a.m. to 6-0 p.m. 29.3.01. Position of ship at noon 9°36’N.,
65°56’E. Wind E.N.E., sea calm.
“16. WAS p.mez; 29.3.01 to 6.30 a.m., 30.3.01. Wind E.N.E., sea calm.
17. 9-15 a.m. to 6-20 p.m., 30.3.01. Position of ship at noon 8°37’N.,
71°27°E. Wind E., sea calm.
*18. 7-30 p.m., 30.3.01 to 6-50 a.m., 31.38.01. Wind E., slight swell.
19. 9-0 a.m. to 6-0 p.m., 31.3.01. Position of ship at noon 7°21'N.,
76°53'H. Wind E., slight swell.
* For the sake of simplicity, the night gatherings are marked with an asterisk,
Notes ON THE COPEPODA.
Calanus pauper, Giesbrecht.
Occurrence, Nos. 1, 2, 4, 5, 6, 7, 8, 9, 11, 13, 14, 15, 16, 17,
1S. 19:
_ This species has already been recorded from the Red
Sea, &e., by Mr. Thompson, (Trans. L’pool Biol. Soe.,
Vol. XIV., p. 275), and from the Pacific Ocean thy ire
Giesbrecht.
Calanus vulgaris (Dana).
Occurrence, Nos. 4, 6, 7, 8, 9, 13, 14, 16, 17, 18.
A widely distributed and sometimes very common
species in tropical and sub-tropical collections of Copepoda.
Calanus darwini (Lubbock).
Occurrence, Nos. 14, 18.
There is no difficulty in recognising the adult female of
this species, which has the last thoracic segment con-
siderably prolonged on the left side, but immature females
present some difficulty owing to the last thoracic segments
ending in a minute tooth, as in Calanus propinquus. There
is, however, a considerable difference in size between the
two species. Calanus caroli, Giesbrecht, of which only
RED SEA AND INDIAN OCEAN COPEPODA. 401
the male is known, has the fifth pair of feet very like those
of the male Calanus darwint, and may easily be passed
over as only a form of the latter.
Eucalanus subtenius, Giesbrecht.
Occurrence, Nos. 6, 7, 18.
This species is closely allied to Hucalanus attenuatus, but
is distinguished by the form of the forehead and its smaller
size. It has hitherto only been found in the Atlantic and
Pacific Oceans. Prof. Cleve records it from the Malay
Archipelago.
Eucalanus crassus, Giesbrecht.
Occurrence, No. 8. A night gathering.
The female of this species is easily recognised by its
robust form and by the appearance of the thoracic segments,
which are clothed with fine hairs. The species is widely
distributed, and has been recorded from the Farée Channel
by my father, Mr. T. Scott (XV. Ann. Rept., Fishery
Board for Scotland, Part III. (1897), p. 312), and from
the Moray Firth (XVIII. A.R., F.B.S., pt. III. (1900),
p. 382). Dr. R. N. Wolfenden also records it from the Farde
Channel, (Jour. Marine Biol. Asso., N.S., Vol. VI., No. 3,
January, 1902). Dr. Giesbrecht records it from the
Atlantic and Pacific Oceans and from the Mediterranean.
It has also been recorded from the Malay Archipelago.
Rhincalanus nasutus, Giesbrecht.
Occurrence, Nos. 8,11. Night gatherings.
There seems to be some doubt whether this Copepod
should be regarded as a distinct species, or only a small
form of Rhincalanus gigas, Brady. The fifth pair of feet
of the female are very like those of R. gigas. Dr.
Giesbrecht’s species measures 39 mm. to 51 mm.
(female), while Dr. Brady gives 8°5 to 10 mm. as the size
of R. gigas. RK. nasutus appears to have a wide distribu-
402 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
tion, and has been recorded from the Farée Channel,
Atlantie and Pacific Oceans, and from the Mediterranean.
Rhincalanus cornutus (Dana).
Occurrence, No. 6. A night gathering.
This species is easily recognised by its projecting fore-
head, and is usually not nearly so rare in tropical
plankton as R. nasutus. Its distribution is also more
extensive.
Paracalanus aculeatus, Giesbrecht.
Occurrence, Nos. 2, 4. Night gatherings.
This Paracalanus is not unlike the next species, but is
easily distinguished from it by the structure of the female
fifth pair of feet. It has already been recorded from the
Indian, Atlantic and Pacific Oceans, and also from the
Mediterranean.
Paracalanus parvus (Claus).
Occurrence, Nos. 1, 2,3, 4,5, 6, .7,°8, 9, 10; El iteine
This species has practically a world-wide distribution.
Acrocalanus gibber, Giesbrecht.
Occurrence, Nos. 4, 5, 6, 7, 8, 9, 12, 15, 16, 19.
This species resembles Paracalanus in size, but is dis-
tinguished from that genus by the fifth pair of feet in the
female being very rudimentary or wanting altogether. It
is widely distributed in tropical and sub-tropical regions.
Calocalanus pavo (Dana).
Occurrence, Nos. 2, 3, 4, 6, 7, 12, 13, 16, 18.
Perfect specimens of this species, which is so well
illustrated by Dr. Giesbrecht, are very rarely obtained in
collections taken by the ship’s pump, the beautiful caudal
sete, as a rule, are broken off, and also the long sete on
the antennules. The species is easily identified, however,
when the caudal furca alone are present; they project at
RED SEA AND INDIAN OCEAN COPEPODA. 4038
right angles to the abdomen. It has a wide distribution
in the warmer waters of the sea.
Calocalanus plumosus (Claus).
Occurrence, Nos. 4, 5, 6, 7, 8, 9, 16, 18.
This species is distinguished from C. pavo by its more
slender form and three-jointed abdomen. In C. pavo the
abdomen is two-jointed. The fifth pair of feet of the
female are also different from C. pavo. Its distribution
is somewhat similar to the above, but it does not appear to
have been previously recorded from the Red Sea and
Indian Ocean.
Clausocalanus furcatus (Brady).
Occurrence, Nos. 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 13, 14, 15, 16,
ies, 19.
Closely allied to Clausocalanus arcwicornis (Dana), but
easily distinguished from that species by the genital or
first abdominal segment being shorter than each of the two
following segments, and by the caudal furea being nearly
twice as long as broad. It will probably be found to have
a wide distribution.
Euchaeta marina (Prestandrae).
Occurrence, Nos. 6, 8, 9, 13, 14, 15, 17, 18.
This is one of the most widely distributed and usually
most abundant members of the genus.
Scolecithriz dane (Lubbock).
Occurrence, Nos. 9, 11, 16, 18.
This appears to be a widely distributed species, but does
not appear to have been recorded from the upper regions
of the Indian Ocean. No. 9 gathering was taken about
40’ HK. of Aden. All the four gatherings were taken
during the night.
Centropages furcatus (Dana).
Occurrence, Nos. 2, 3, 6, 8, 9, 16, 18, 19.
404 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
Centropages orsinit, Giesbrecht.
Occurrence, Nos. 4, 5, 8, 9, 11, 12.
This species has only been recorded from the Red Sea,
and the present collection extends its distribution into the
Gulf of Aden.
Centropages calaninus (Dana).
Occurrence, Nos. 1, 2, 3.
This species resembles C. violaceus in appearance, but
the male is easily recognised by its fifth pair of feet. It
has only previously been recorded from the Pacific Ocean.
Centropages elongatus, Giesbrecht. Plate L., figs. 13
and 14.
Occurrence, Nos. 4, 5, 12, 14, 18, 19. .
This Centropages also resembles C. violaceus in
appearance, but the fifth pair of feet in the male are quite
distinct from C. volaceus or C. orsinw. Dr. Giesbrecht
found this species in plankton collected by the aid of the
ship’s pump by Dr. A. Kramer, when passing through the
Red Sea at the end of July, 1895. The gatherings in which
C’. elongatus were found by Giesbrecht were taken between
15° N. and 27° N. well inside the Red Sea. The Robinson
collection extends the distribution into the Indian Ocean
to near Colombo. The figures show a dorsal view of the
male, which measured 2°2 mm., and the male fifth feet.
Pseudodiaptomus serricaudatus (T. Scott). Plate L., fig. 6.
Occurrence, Nos. 8,9. Both night gatherings, near Aden.
This species was first discovered by Mr. T. Scott in a
collection of Copepoda, &c., from the Gulf of Guinea,
West Coast of Africa. It has since been recorded from
India.
Temora stylifera (Dana).
Occurrence, | Nos. 6, 7, 8, 9, 10, 12, 13, 14, 16, 18, 19.
RED SEA AND INDIAN OCEAN COPEPODA. 405
Temora discaudata, Giesbrecht.
Occurrence, Nos. 1\2, 4,5, 6, 7; 8,9, 10, 11, 13,16, 18.
These two species were widely distributed throughout
the Robinson collection.
Pleuromamma abdominalis (Lubbock).
Weeurrence, Nos. 2, 3, 4, 6, 7, 8,9, 16, 18.
This appears to be a widely distributed species, and is
recorded from the Farée Channel and the Shetland waters
by Dr. Wolfenden. It is also recorded from the
Mediterranean, Red Sea, Atlantic, Pacific and Indian
Oceans, and from the Malay Archipelago.
Pleuromamma gracilis (Claus).
Occurrence, Nos. 9, 13, 18.- All night gatherings.
The distribution of this species is somewhat similar to
the last, but it has not been found so far north as the
Tarde Channel.
Lucicutia flavicornis (Claus).
Oecurrence, Nos. 2, 4, 6, 7, 9, 18.
Candacia ethiopica Dana.
Occurrence, Nos. 9, 13, 14, 15, 16, 17, 18, 19.
This distinct species was observed in all the gatherings
taken after leaving the Gulf of Aden. It has already been
recorded from the Indian Ocean and Bay of Bengal by Mr.
Thompson.
Candacia catula, Giesbrecht.
Occurrence, Nos. 6, 16, 18, 19.
Giesbrecht records this species from the Pacific Ocean
and Red Sea. Professor Cleve (Kongl. Svenska Veten.
Akad. Handl. Band. 35, No. 5, p. 5), records it from the
Malay Archipelago, which appears to be all the distribu-
tion yet known.
406 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
Candacia bispmosa, Claus.
Occurrence, No. 11. A night gathering.
This species has been recorded from the Mediterranean
and Pacific Ocean only.
Candacia truncata, Dana.
Occurrence, Nos. 4, 9, 12, 16, 18.
The distribution of this species is similar to that of
Candacia ethiopica reterred to above.
Candacia bradyi, n. sp. Plate L., figs. 9-12.
1883. Candace pectinata, part, Brady Rept. voy. ‘‘ Challenger ’”’
Copepoda, vol. 8, p. 67, pl. xxx., fig. 9 only.
Occurrence, Nos. 8, 9. Both night gatherings, near Aden.
Only the male of this species has been observed. Length
2mm. In general appearance it resembles the male of
C. varicans, Giesbrecht, but the terminal spines of the
last thoracic segment are much smaller and the abdomen
is slightly asymmetrical. The chief difference between
Candacia bradyi and the other described species is in the
structure of the fifth pair of feet. The drawing, fig. 11,
represents this pair, which is practically the same as the
fig. (9) given by Professor Brady on Plate XXX. of his
Report on the “Challenger” Copepoda, but is quite
different from the fifth feet of the male of Candacia
pectinata, occasionally taken in British waters. I have
compared with specimens of C. pectinata from the Clyde
collected by my father.
Calanopia elliptica (Dana).
Occurrence, Nos. 1, 2, 4, 6, 7, 8, 11.
This species is widely distributed throughout the
Robinson collection, and has already been recorded from
the same region by Mr. Thompson.
Calanopia minor, n. sp. Plate L., figs. 1-5.
Occurrence, Nos. 4, 6, 7, 8, 11, 13, 16, 18.
RED SEA AND INDIAN OCEAN COPEPODA. 407
Length of female, 1:15 mm. Length of male, 1:16 mm.
This species resembles C. elliptica, but can be easily
identified by its smaller size and more slender abdomen.
The side view of the female abdomen shows it to be very
little wider than the caudal furca. The species is mainly
distinguished from C. elliptica, however, by the structure
of the fifth pair of feet. The fifth pair in the female is
one-branched, and each foot is composed of three joints of
nearly equal length. The right and left feet are quite
symmetrical. The second joint has one short seta on the
middle of the outer margin. The third, or terminal joint,
has one seta on the outer margin about two-thirds from
the base and two on the apex, the inner one being rather
longer than the joint. The inner seta on the right foot is
rather longer than the same seta on the left foot. The
fifth pair in the male is also one-branched, and each foot
is composed of four joints. The basal joint of the left
foot is very small, and only about two-fifths the length of
the second joint. Second and third joints of nearly equal
length. The second joint has a projection on the inner
margin near the base. Fourth joint small and only about
half the length of the third joint. The right foot is
modified for grasping. See fig, 5.
Calanopia americana, Dahl, (Ber. Ges. Freiburg N.S.,
Vol. 8, p. 21, t. 1, figs. 23-26), and Calanopia auriwillii,
Cleve, (Kongl. Vet. Akad. Handl. Bd. 35, No. 5, p. 82,
pls. 2 and 3), are very like Calanopia minor in general
appearance, but the structure of the fifth pair of feet, both
in the male and female, are different.
Labidocera acuta (Dana).
Occurrence, No. 8. A night gathering, 40’ west of Aden.
Labidocera minuta, Giesbrecht.
Occurrence, Nos. 7, 10, 16.
408 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
The only localities recorded for this species are Pacific
and Red Sea (Giesbrecht), and from
the Arabian Sea by Professor Cleve.
Ocean— Hong-Kong
Pontella fera, Dana.
Occurrence No.6. A night gathering, near the end of the
Red Sea.
This species has been recorded from the Pacific and
Indian Oceanus only; the Red Sea is therefore a new
locality for it.
Pontellina plumata (Dana).
Occurrence, Nos. 2, 9, 12, 16, 18.
Pontellina plumata has a wide distribution, and has been
recorded from the Mediterranean, Atlantic, Pacific, and
Indian Oceans, but not from the Red Sea.
Acartia negligens, Dana.
Occurrence, Nos. 1, 2, 3, 4, 5, 6, 8, 9, 13, 14, Ib) tees:
This is a widely distributed species, and has been
recorded from the Mediterranean, Red Sea, and Pacific
Ocean. The Robinson collection extends its distribution
into the Indian Ocean. Cleve has recently recorded it
from the Arabian Sea and Malay Archipelago.
Acartia erythrea, Giesbrecht.
Occurrence, Nos. 1, 5, 6, 8. No.1, Gulf of Suez; 3, 6, 8,
Red Sea.
Until recently the Red Sea was the only region where it
was known to live. Mr. Thompson (Trans. L’pool Biol.
Soc., Vol. XIV., p. 284), records it from the Indian Ocean,
and Prof. Cleve, op. ct., records it from the Malay
Archipelago.
Oithona plumifera, Baird.
Occurrence, Nos. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 16,
1G:
RED SEA AND INDIAN OCEAN COPEPODA. 409
Oithona plumifera has not previously been recorded
from the Red Sea. Mr. Thompson records it from the
Indian Ocean, and Professor Cleve from the Arabian Sea
and Malay Archipelago.
Oithona similis Claus.
Weeurrence, Nos. 1, 2, 5,.6, 7, 8, 9, 10, 15, 16, 17, 18, 19.
This Ozthona has already been recorded from the Red
Sea and Indian Ocean by Mr. Thompson. Professor Cleve
records it from the Arabian Sea, and doubtfully from the
Malay Archipelago.
Oithona minuta, T. Seott.
Occurrence, Nos. 4, 7, 8, 12, 16, 19.
This very small but quite distinct species occurred
sparingly in the gatherings referred to. It does not appear
to have been recorded from any other region excepting
the Gulf of Guinea, where it was first found.
Longipedia coronata, Claus.
Occurrence No. 1. Near Suez.
Not previously recorded from this region.
FEictinosoma atlanticum (Brady & Robertson).
Occurrence, Nos. 1, 4, 8, 11, 16, 17, 19.
This species has a wide distribution, and ranges from
the Farée Channel to the warm seas.
Euterpe acutifrons (Dana).
Occurrence, Nos. 1, 2, 3, 4, 6, 7, 8, 9, 10, 11, 13.
This species has also a wide distribution.
Setella gracilis, Dana.
Weemrrence, Nos. 1, 2, 4, 5, 6, 7, 8, 9, 11, 12, 18, 15, 16, 17,
18, 19.
Miracia efferata, Dana.
Occurrence No. 15. A night gathering.
410 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
Clytemnestra scutellata, Dana.
Occurrence, Nos. 4; 6, 7, 8,9, 11, 12, 13, lo, 17, 2S7no
Ectinosoma atlanticum, Euterpe acutifrons, Setella gracilis,
Miracia efferata, and Clytemnestra scutellata, have already
been recorded by Mr. Thompson from the greater part of
the region traversed by the Robinson collection.
Stenhelia irrasa, n. sp. Plate IIL, figs. 6-10.
Occurrence, Nos. 4, 5.
Description of the Female—Length ‘76 mm. Body
elongate, slender; rostrum small and slightly curved. The
abdomen is ornamented with a few rows of minute spines
on the dorsal and lateral surfaces near the posterior end of
the joints. The antennules are short and five-jointed ;
the fourth joint is smaller than any of the others, and
the fifth joint in some positions has an indication of a
dividing line near the middle. The formula shows the
proportional lengths of the joints.
Proportional lengths of the joints - 6 2 383 1 8
Number of the Joints - - = A 205 23.)
Antenne, mandibles, maxilla, and foot jaws somewhat
similar to those of Stenhelia oma, Brady. First four pairs
of swimming feet also resembling those of S. ama. The
fifth pair of feet are small and foliaceous. The inner
branches are sub-triangular, and furnished with three
plumose sete on the inner distal margin and two on the
apex. The outer branches are pyriform in shape, and
furnished with two plumose sete on the outer, and two on
the inner distal margins, and one on the apex (fig. 9).
Caudal furea very short. ‘
Remarks.—This species, though somewhat like Sienna
ima, is readily distinguished from it, and any of the other
members of the genus, by the structure and proportional
lengths of the joints of the antennules, and by the form of
the fifth pair of feet.
RED SEA AND INDIAN OCEAN COPEPODA. 411
Stenhelia erythrea, n. sp. Plate IIT., figs. 11-14.
Occurrence, Nos. 4, 5.
Description of the Female—Length ‘79 mm. Body
elongate, slender; rostrum prominent and_ curved.
Abdomen without any ornamentation. The antennules
are moderately long and slender, eight-jointed; the fifth
and sixth joints are shorter than any of the others. The
formula shows the proportional lengths of the joints.
Proportional lengths of the jomts - 12 12 8 8 38 2 4 7
Number of the joints - - ah ee GAGs oes ob. OH ing, sv 78
The antenne, mandibles, maxille, and foot jaws are
similar to those of S. irrasa. The first four pairs of
swimming feet are somewhat like those of S. 7ma. The
fifth pair of feet are larger than those of S. wrasa, and
more elongated. The inner branches are furnished with
' four plumose setz on the inner distal margin and two on
the apex. The outer branches have four plumose sete
on the outer distal margin, one on the apex, and one on
the inner margin near the apex (fig. 14). Caudal furca
very short.
Remarks.—This species is distinguished from S. irrasa
by the structure of the antennules, and by the form of the
fifth pair of feet.
Delavalia mopinata, n. sp. Plate III., figs. 19-22.
Occurrence, Nos. 1, 4, 12, 19.
Description of the Female—Length ‘63 mm. In general
appearance somewhat similar to D. palustris, Brady. The
antennules are eight-jointed, and resemble those of
D. emula, T. Scott. The formula shows their proportional
lengths.
Proportional lengths of the joints - 6 5 5 44 38 4 8 4
Number of the joints’ - - aqeeleee Oe Gide Men MGre eur B
The antenne, mandibles, maxille, and foot jaws are
412 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
similar to those of D. palustris. The first pair of swimming
feet have the inner branches composed of two joints, as in
D. palustris, but the first joint is proportionally shorter
and the second joint longer and narrower than in that
species. The second joint is furnished with two sete on
the inner margin and two at the apex; the outer branches
are armed like those of D. palustris. The second, third,
and fourth pairs of swimming feet resemble those of
D. palustris. The fifth pair of feet have the basal joints
only slightly produced. The apex of the jjoints is irregu-
larly angular, and furnished with four sete placed equi-
distant from each other. The outer branches are sub-
quadrangular in shape, being longer than broad. They
are furnished with one sete on the outer margin near the
apex, and four on the apex, the second from the exterior
being shorter than the other sete (fig. 22). Caudal furea _
slightly longer than the last abdominal segment.
Remarks.—This species at first sight is not unlike
Delavahia palustris, but on examination is easily dis-
tinguished from it by the proportional lengths of the joints
of the antennules, the structure of the first feet, and also
of the fifth feet.
Delavalia minuta, n. sp. Plate IIL, figs. 15-18.
Occurrence, Nos. 1, 3, 4, 19.
Description of the Female—Length ‘48 mm. Some-
what similar in shape to the last species, but smaller and
with rather longer caudal furca. The antennules are
eight-jointed, and resemble those of D. robusta, Brady.
The formula shows the proportional lengths of the joints.
Proportional lengths of the joints - 5 8 5 4 4 4 38 56
Number of the joints - - . -1.1, 2 (3. 4 = (6)
The first pair of swimming feet have the inner branches
two-jointed, like those of D. znopinata, but the basal joint
is proportionally longer, and the second joint shorter and
RED SEA AND INDIAN OCEAN COPEPODA. A418
wider throughout its length. The second, third and fourth
pairs of swimming feet are similar to those of D. inopinata.
The fifth pair of feet have the basal joint very small and
triangular in shape, and furnished with two sete at the
apex. ‘The outer branch is pyriform, and resembles that
of D. robusta. The inner and outer margins are each
furnished with one seta, while the apex has three (fig. 18).
Caudal furca equal to the combined lengths of the last
two abdominal segments.
Remarks.—This species is easily distinguished from
D. inopinata by the structure of the fifth pair of feet and
the longer caudal furca.
Laophonte pygmea, T. Scott.
Occurrence, No. 1.
This species does not appear to have been recorded from
any other region outside the Gulf of Guinea, where it was
first found by Mr. T. Scott.
Laophonte inornata, n.sp. Plate IL. figs. 9-14;
Plate I., fig. 16.
Occurrence, Nos. 1, 3, 5.
Description of the Female—Length ‘66 mm. Body
slender, with very angular jointed thorax. Rostrum small
and entire, with a minute seta at each side. Antennules
slender, seven-jointed. The fourth and fifth joints are
very small. The second joint has a minute but distinct
- tooth on its lower surface. The formula shows the pro-
portional lengths of the joints.
Proportional lengths of the joints - 8 8 8 2 2 8 6
Number of the joints - - <i de Deo Aa NOE OMIT
Antenne, mandibles, maxille,-and foot jaws, as in
Laophonte similis, Claus. The inner branches of the first
pair of swimming feet are slender, and armed with a
moderately long terminal claw, The outer branches are
GG
414 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
small and three-jointed, and do not reach to the middle of
the first joint of the elongated inner branches (fig. 12).
The outer branches of the second, third, and fourth pairs
of feet are three-jointed. The inner branches are short
and two-jointed, with the first joint very small. The
structure of the fifth pair is similar to those of L. dentz-
cornis, T. Scott, except that the basal joint is not rounded
on its inner margin. ‘The basal joint is furnished with
three plumose setz on the inner margin, and two sub-
apical sete. The outer branch is furnished with three
small sub-apical setze on the outer margin, one small sub-
apical seta on the inner margin, and one long apical seta.
Caudal furca slender, about two-thirds the length of the
last abdominal segment.
Remarks.—This species resembles Laophonte thoracica
in some of its characters, but the structure of the anten-
nules, the fifth pair of feet, and the caudal furea easily
distinguish 1.
Laophonte herdmani, n.sp. Plate IIL. figs. 3-8;
Plate L., fig. 15.
Occurrence, Nos. 1, 3, 5.
Description of the Female—Length 66 mm. Body
slender, with straight jointed thorax; rostrum small and
cleft, with a minute seta at each side. Antennules
moderately robust, six-jointed. The fourth and fifth joints
are very small. The second joint has a minute tooth on
its lower surface. The proportional lengths of the joints
are shown by the following formula : —
Proportional lengths of the joints - 11 10 10 2 2 8
Number of the joints - - . Seki 2 3 4 5 6
The antenne, mandibles, maxille and foot jaws are similar
to those: of LZ. znornata. The inner branches of the first
pair of swimming feet are robust, and armed with a strong
terminal claw. The outer branches are small and three-
RED SEA AND INDIAN OCEAN COPEPODA. 415
jointed, scarcely reaching to the middle of the first joint
of the inner branches. ‘The middle joint of the outer
branches is considerably longer than either the first or
third joints. ‘The outer branches of the second, third, and
fourth pairs of feet are three-jointed. The inner branches
are short and two-jointed. The fifth pair of feet resemble
those of L. cwrtecauda in shape, but the basal joint is much
larger, and the outer joint is wider at the apex than at the
base. The inner margin of the basal joint is furnished
with three plumose sete. There is also one apical seta.
The apex of the outer branch is furnished with five sete
of unequal lengths. Caudal furea robust, and longer than
the last abdominal segment. |
Remarks.—This species is easily distinguished from any
of the other described species by the structure of the
antennules and fifth pair of feet.
Cletodes lumicola, Brady.
Occurrence, Nos. 1, 9, 16.
This quite distinct and easily identified species does not
appear to have been recorded from any region outside the
British seas. |
Dactylopus tisboides, Claus.
Occurrence, No. 1.
Not previously recorded from this region.
Dactylopus strom (Baird).
Occurrence, No. 1.
Not previously recorded from this region.
Dactylopus robinsonii, n. sp. Plate IIL., figs. 1-5.
Occurrence, No. 18.
Description of the Female—Length ‘62 mm. Body
moderately robust; rostrum prominent and curved.
Antennules slender and eight-jointed. The fifth, sixth
and seventh joints are all of about equal size, and much
416 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
smaller than any of the others. The formula shows the
proportional lengths.
Proportional lengths of the joints - 6 6 5 6 2 2 9Q9 5
Number of the joints” - - - 1 2-3 4" 20 Gee
Antenne, mandibles, maxille, and foot jaws resembling
those of D. strémi. Both branches of the first pair of
swimming feet robust and three-jointed. The outer
branch scarcely reaches to the end of the first joint of the
inner branch, the second joint is shorter than the first,
and the third joint is shorter than the second. The second
and third joints of the inner branch are very short, and
of about equal size. The third joint is furnished at its
apex with one short, stout claw and one long flexed seta.
There is also a minute seta on the inner apical angle.
The second, third and fourth pairs resemble those of
D. strému, but are smaller. The fifth pair of feet are
somewhat similar to the fifth pair in Stenhelra wrrasa
already described. The inner margin of the basal joint
is furnished between the middle and the apex with three
plumose sete, and there are two sub-apical sete on the
outer margin. ‘The apex is destitute of set, so that
there is a distinct space between the sete on the outer and
inner margins. The outer branch is furnished with two
setee on the outer, two on the inner margins and one on
the apex (fig. 4). Caudal furca very short.
Remarks.—The characters of the antennules and fifth
feet easily distinguish this small species from any of the
other described members of the genus.
Pseudothalestris major (Tv. & A. Scott).
1895. Pseudowestwoodia major. T.& A.S. Ann. & Mag. Nat.
Hist., Ser. 6, vol. xv., p. 56, pl. vi., figs. 17-20.
Occurrence, No. l.
This small species, which closely resembles Westwoodia
RED SEA AND INDIAN OCEAN COPEPODA. AT
nobilis (Baird) in general appearance, has not previously
been recorded from any region outside the British seas.
Harpacticus chelafer (Muller).
Occurrence, Nos. 1, 3, 6, 17.
Harpacticus chelifer has been recorded from the Gulf of
Guinea and Franz-Joseph Land by Mr. T. Scott, which
indicates that the species has a wide distribution.
Altevtha bopyroides, Claus.
Occurrence, Nos. 1, 4.
This species is frequently found in surface tow-net
gatherings taken in the British seas.
Idya furcata (Baird).
Occurrence, Nos. 1, 13, 17, 18, 19.
From the above records it will be seen that this species
had a wide distribution in the Robinson collection.
Ilyopsyllus affinis, T. Scott.
Occurrence, No. l.
This species appears to be quite distinct from
I. corvaceus, Brady and Robertson. The caudal sete in
the female are not spatulate. The species does not appear
to have been recorded from any other region outside the
Gulf of Guinea.
Inchomolgus minor, n. sp. Plate II., figs. 15-24;
Plate L., fig. 17.
Occurrence, No. 1.
Description of the Female—Length ‘9 mm. In general
appearance resembling Lichomolgus furcillatus, Thorell.
Antennules seven-jointed ; the last joint very small. The
formula shows their proportional lengths.
Proportional lengths of the joints - 10 18 7 13 13 9 4
MumberoftheJoints .- - - 1 2 8 4 & 6 7
The antenn are four-jointed, the third joint being much
smaller than any of the others. The apex of the fourth
418 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
joint is furnished with five sete. The mandibles are
small, dilated at the base, and produced into a long curved
stylet-shaped seta ciliated in both margins. Basal part
of the anterior foot jaws stout, and produced into a long
slender spine, ciliated on its upper margin. There is also
a moderately long ciliated spine attached to the outer
margin, near the apex of the stout basal part. Posterior
foot jaws three-jointed ; last joint very short, and furnished
with aclaw. Both branches of the first, second, and third
pairs of swimming feet three-jointed. The outer branches
of the fourth pair of feet are also three-jointed, but the
inner branches are composed of two joints; basal joints
small. The fifth pair of feet are small, and consist of a
single joint, furnished with two sete. The abdomen is
composed of four joints, the third joint being smaller than
any of the others. Caudal furca nearly as long as the
combined lengths of the last three abdominal segments.
Remarks.—This species is a true Lichomolgus, the genus
being now restricted to species having the inner branches
of the fourth pair of feet composed of two joints.
Formerly the genus included other two types, which have
the inner branches of the fourth pair composed of one and
three joints respectively, as follows :—
Pseudanthessius. Inner branches of fourth pair composed of one joint.
Lichomolgus. i ¥, as two joints.
Hermanella. i vis ” three joints.
Oncea venusta, Phillipi.
Occurrence, Nos. 1, 2, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, Lo,
faye:
Oncea conifera, Giesbrecht.
Occurrence, Nos. 6, 11, 13, 16, 18.
Oncea venusta has already been recorded by Mr.
Thompson from the Red Sea, but it does not appear to
have been previously recorded from the region between
RED SEA AND INDIAN OCEAN COPEPODA. 419
Aden and Colombo. O. conifera has not been recorded
from the region traversed by the Robinson collection.
Oncea notopus, Giesbrecht.
Occurrence, Nos. 3, 5, 7.
Only previously recorded from the Pacific Ocean.
Oncea media, Giesbrecht.
Occurrence, Nos. 4, 6.
Not previously recorded from the Red Sea. Professor
Cleve has recently recorded it from the Arabian Sea,
Indian Ocean and Malay Archipelago.
Lubbockia squillumana, Claus.
Occurrence, Nos. 4, 8.
This species has not previously been recorded from the
Red Sea region.
Sapphirina nigromaculata, Claus.
Occurrence, Nos. 4, 7, 12.
This Sapphwina has already been recorded from the
Red Sea.
Sapphurina auronitens, Claus.
Occurrence, Nos. 16, 17, 18.
Previously recorded from the Atlantic and Mediterranean
only. |
Sapphwina vorax, Giesbrecht.
Occurrence, Nos. 6, 13, 18.
Previously recorded from the Atlantic and Mediterranean
only.
Sapphirima pyrosomatis, Giesbrecht.
Occurrence, Nos. 9, 16.
Previously recorded from the Atlantic and Mediterranean
only.
Sapphirina maculosa, Giesbrecht.
Occurrence, Nv. 8.
42.0 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
Previously recorded from the Atlantic and Mediterranean
only.
None of the last four Sapphirina appear to have been
recorded from the region traversed by the Robinson
collection.
Copilia mirabilis, Dana.
Occurrence, Nos. 7, 9.
Coryceus ovalis, Claus.
Occurrence, Nos. 1, 7, 10, 18.
Not previously recorded from the Gulf of Suez or the
Red Sea.
Coryceus venustus, Dana.
Occurrence, Nos.1, 2, 4,'6, 7, 9, 11, 13, 14, 16s
Mr. Thompson has already recorded this species from the
region traversed by the Robinson collection.
Coryceus danae, Giesbrecht.
Occurrence, Nos. 1, 7, 8, 9, 18, 19.
This species has not previously been recorded from the
Gulf of Suez or the Red Sea. Professor Cleve records it
from the Arabian Sea and Indian Ocean.
Coryceus speciosus, Dana.
Occurrence, Nos. 1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 13, 18.
Mr. Thompson records this Coryceus from the Indian
Ocean, but there appears to be no record of its occurrence
between the Island of Socotra and Suez.
Coryceus gibbulus, Giesbrecht.
Occurrence, Nos. 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 18, 14,
155 LG) Lia Ss 9:
Coryceus gibbulus occurred in all the gatherings with the
exception of No. 1. Mr. Thompson records it from the
Red Sea region, &c., and Professor Cleve from the
Arabian Sea and Indian Ocean.
RED SEA AND INDIAN OCEAN COPEPODA. 491
Coryceus carinatus, Giesbrecht.
Occurrence, Nos. 16, 18.
Mr. Thompson records this species from the middle of
the Indian Ocean. It has also been recorded from the
Pacific.
Coryceus furcifer, Claus.
Occurrence, No. 9. Gulf of Aden.
Not previously recorded from this region.
Coryceus gracilicaudatus, Giesbrecht.
Occurrence, No.9. Gulf of Aden.
Professor Cleve records this species from the Indian
Ocean and Malay Archipelago.
Coryceus obtusus, Dana.
Occurrence, Nos. 1, 4, 6, 8, 9, 10, 12, 14, 19.
There appear to be no previous records from the Gulf
of Suez or Red Sea. Professor Cleve records it from the
Arabian Sea, Indian Ocean, and Malay Archipelago.
Coryceéus concummus, Dana.
Occurrence, Nos. 12, 13, 14, 15, 16, .17, 18, 19.
Coryceus lubbocki, Giesbrecht.
Occurrence, Nos. 4, 5, 7, 8, 12, 18, 14, 16, 17, 19.
The last two Coryceus have not previously been recorded
from the region traversed by the Robinson collection.
The two following species of Ostracoda were observed in
the collection : —
Philomedes gibbosa. (Dana.)
Occurrence, Nos. 2, 3, 4, 6, 18.
Halocypris atlantica, Lubbock.
Occurrence, Nos. 4, 13.
499. TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
(2) Dr. Jameson’s CoLiection.
The second collection was given to me by Dr. H. Lyster
Jameson, by whom it was made, with the following note:
“This collection was taken at the end of April, 1901, on
“the ‘Shelling Grounds’ in Fortescue Straits, a passage
“about half a mile wide and five miles long, between
“Sidea, Basilisk Island, and Basilaki, Moresby Island.
“The depth varies from fifteen fathoms to forty fathoms.
“Currents, up to so much as five knots per hour, run
“through it between the Coral Sea and Goschen Strait.
“The tidal current runs direct between the Pacific and
“Indian Oceans. The shell is Margaritifera maxima,
‘““ Jameson—one of the pearl oysters. This species of pearl
’ “oyster is always found on grounds where there is a
“tremendously rich plankton.”
The collection was represented by one surface tow-
netting, containing about five c.c. of solid matter, chiefly
Copepoda. The Copepoda consisted of thirty-five species.
Although no new species were obtained, the gathering is
of much interest, as it increases our knowledge of the
distribution of described forms.
Amongst the other organisms in the collection, a number
of examples of the Peridinian, Ceratiwm tripos, in the
chain condition, were observed. According to Mr. George
Murray, this state of Ceratvwm has ‘been observed only in
the open sea, far away from land. It is probable that the
strong currents referred to by Dr. Jameson may have been
the means of conveying it so close to land in this instance.
List oF CoPpEPODA.
Calanus minor (Claus). Oithona plumifera, Baird.
Mecynocera claus, » Unearis, Giesb.
I. C. Thomps. » brevicornis, Giesb.
RED SEA AND INDIAN OCEAN COPEPODA. 493
Paracalanus aculeatus, Giesb. Ectinosoma atlanticum
My parvus (Claus). (Ba & B:)
Calocalanus pavo, Dana . rosea (Dana).
,, plumosus (Claus). Huterpe acutifrons (Dana).
Acrocalanus gibber, Giesb. —_ Setella gracilis, Dana.
Clausocalanus furcatus Oncea venusta, Phillppi.
(Brady). ,, conifera, Giesb.
Centropages brachiatus (Dana). Coryceus venustus, Dana.
orsinit, Giesb. 5 obtusus, Dana.
rs furcatus (Dana). s speciosus, Dana.
Temora discaudata, Giesb. . gibbulus, Giesb.
Haloptilus longicornis (Claus). Bi robustus, Giesb.
Calanopia elliptica (Dana). Es concinnus, Dana.
* Pontellopsis krdmeri (Giesb). i lubbocki, Giesb.
Acartia erythrea, Giesb. Conea rapax, Giesb.
Tortanus gracilis, Brady. Halocypris aculeata, T. Scott.
Oithona nana, Giesb. .
* Pontellopsis krdmeri (Giesbrecht). Plate L., figs. 7
and 8; Plate IL., fies. 1 and 2.
1896, Monops krémeri. Giesb. Zool. Jahrb. Syst., vol. 9, p. 323,
t. 5, figs. 1 and 2,
The occurrence of this species in Fortescue Strait is
particularly interesting. The species has hitherto only
been known to occur in the Red Sea, where it was dis-
covered by Dr. Giesbrecht in plankton collected with the
aid of a ship’s pump by Dr. Kramer, when sailing up in
1895. Only the female was found. One male and one
female were obtained from Dr. Jameson’s collection.
Length of female, 1:98 mm. Length of male, 16 mm.
The female is easily distinguished from any of the other
Pontellopsis by the right caudal furea being about twice
as long and broad as the left furca. The fifth pair of
feet are also very distinct. The male, in general
A494 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
appearance, resembles the males of P. strenwa and
P. perspicax, but, unlike them, it has no spine on the left
extremity of the last thoracic segment. The last thoracic
segment of P. krdmeri ends in a rounded knob on the left
side, and in a long, almost straight spine on the right side.
The spine reaches to near the end of the third joint of the
abdomen. The third abdominal joint is larger than any
of the other joints, and has a prominent protuberance on
the right margin near its articulation with the second
joint. The right foot of the fifth pair has the claw on the
grasping joint nearly as long as the end hook.
List oF WORKS REFERRED TO.
Das Tierreich, Copepoda. 1. Gymnoplea.
Fauna u. Flora des, Golfes von Neapal. Vol. xix. Pelagischen copepoden.
Monograph British Copepoda. G.S. Brady. (Ray Society).
Die Frei lebenden Copepoden, Claus,
Report on Entomostraca from the Gulf of Guinea, T. Scott, Trans. Linn.
Soc., London, ser. ii., vol. vi.
Report on two collections of Tropical and more Northerly Plankton, I. C.
Thompson, Trans. L’pool Biol. Soc., vol. xiv.
Annual” Reports Fishery Board for Scotland (Part III.), papers on
Copepoda by T. Scott,
Plankton from the Indian Ocean and the Malay Archipelago.
P. T. Cleve (Kongl. Svenska Vetenskaps-Akademiens Handlinger,
Bandet 35, No. 5).
PrEL LABORATORY,
April, 1902. K
ic: «9.
Fig. 10.
Fig. 11
Fig. 12
Fig. 13
Fig. 14
_ RED SEA AND INDIAN OCEAN COPEPODA. 495
EXPLANATION OF PLATES.
Puate I.
. Calanopia minor, n. sp., female, dorsal view. x 51,
2. Calanopia minor, n.sp., female, last thoracic seg-
ment and abdomen, left side. x 51.
. Calanopia minor, n. sp., male, last thoracic segment
and abdomen, dorsal view. xX 77.
. Calanopia minor, n.sp., female, fifth pair of feet.
<x 210.
. Calanopia minor, n.sp., male, fifth pair of feet.
< 154:
. Pseudodiaptomus serricaudatus, (T. Scott), female,
fifth pair of feet. x 154.
. Pontellopsis kramert (Giesb.), male, fifth pair of
neers xX TT.
. Pontellopsis kramert (Giesb.), female, fifth pair of
feet. x 55.
Candacia bradyi, n.sp., male, dorsal view. x 31.
Candacia bradyi, n.sp., male, last thoracic and
first abdominal segments, left side. x 51.
Candacia bradyi, n.sp., male, fifth pair of feet.
oat
Candacia bradyi, n.sp., male, left branch of fifth
pair of feet, lateral view. xX 77.
Centropages elongatus (Giesb.), male dorsal view.
x 38.5.
. Centropages elongatus (Giesb.), male, fifth pair of
Hee. ox 71,
426
Rg: 9:
Fig. 10.
. Laophonte inornata, n.sp., female, antennule.
Fig. 15.
TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
. Laophonte herdmant, n.sp., female, foot of fifth
pair of feet. x 210.
. Laophonte inornata, n.¢p., female, foot of fifth pair
orteet, <220:
. Lichomolgus minor, n. sp., female, mandible. x 180.
Puate II.
. Pontellopsis kramert (Giesb.), male, dorsal view. —
XtSO:
. Pontellopsis kramert (Giesb.), female, last thoracic
segment and abdomen. x 38.5.
. Laophonte herdmant, n.sp., female, left side. x 77.
. Laophonte herdmani, n. sp., female, rostrum. x 260.
. Laophonte herdman, n.sp., female, antennule.
x 210.
. Laophonte herdmant, n.sp., female, foot of first
pair of feet. x 210.
. Laophonte herdmani, n.sp., female, foot of fourth
pair of feet. x 210.
. Laophonte herdmant, n.sp., female, last abdominal
segments and caudal furca. x 100.
Laophonte inornata, n.sp., female, left side. Xx 77.
Laophonte mn-rnata, n. sp., female, rostrum. x 260.
x 210.
. Laophonte inornata, n. sp., female, foot of first pair
oktect. — >< 210;
. Laophonte inornata, n.sp., female, foot of fourth
pair of feet. x 210.
. Laophonte inornata, n. sp., female, last abdominal
seements and caudal furca. x 100.
Lichomolgus minor, n.sp., female, dorsal view.
eT.
~]
RED SEA AND INDIAN OCEAN COPEPODA. 427
. Lichomolgus ninor, n.sp., female, rostrum. x 175.
. Iichomolgus minor, n.sp., female, antennule.
x 210.
. Lichomolgus minor, n.sp., female, antenna. xX 175.
. Lichomolqus minor, n. sp., female, anterior foot jaw.
VAP
. Lichomolqus minor, n. sp., female, posterior foot jaw.
xe 710:
. Iachomolgus minor, n.sp., female, foot of first pair
Oneeta. — LO:
. Lichomolgus minor, n.sp., female, foot of fourth
pair of feet. x 150.
. Lichomolgus minor, n.sp., female, foot of fifth pair -
OIC te te FD:
. Inchomolgus minor, n.sp., female, last abdominal
seoment and caudal furea. xX 175.
Puate IIL.
. Dactylopus robinson, n.sp., female, left side.
Ae
. Dactylopus. robinsonw, n.sp., female, antennule.
ANS
. Dactylopus robinsonii, n.sp., female, foot of first
pair of feet. x 216.
. Dactylopus robinsonu, n.sp., female, foot of fifth
pair of feet. x 216.
. Dactylopus robinsonii, n.sp., last abdominal
segments and caudal furca. x 100.
. Stenhelia irrasa, n.sp., female, left side. x 77.
. Stenhelra rrrasa, n. sp., female, antennule. x 216.
. Stenhelia wrasa, n.sp., female, foot of first pair of
feet. xX 154.
428
Ric. “9:
Fig. 10.
Fig. 11.
Fig. 12.
Fig. 13.
Fig. 22.
TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
Stenhelia wrrasa, n.sp., female, foot of fifth pair of
feet. x 216.
Stenhelia irrasa, n.sp., female, last abdominal
segments and caudal] furca. x 100.
Stenhelia erythrea, n.sp., female, left side. x 77.
Stenhelia erythrea, n.sp., female, antennule.
2G:
Stenheha erythrea, n.sp., female, foot of first pair
of feet. x 185.
. Stenhelia erythrea, n.sp., female, foot of fifth pair
of feet: ~~ x« ALG.
. Delavalia minuta, n. sp., female, left side. x 77.
. Delavalia minuta, n.sp., female, antennule. x 216.
. Delavalia minuta, n.sp., female, foot of first pair
of feet.” <x QIG:
. Delavalia minuta, n.sp., female, foot of fifth pair
OL hee: OX me LO:
. Delavalia inopinata, n. sp., female, left side. x 77.
. Delavalia inopinata, n.sp., female, antennule.
Gs
. Delavalia inopinata, n.sp., female, foot of first pair
of feet. x 180.
Delavalia inopinata, n.sp., female, foot of fifth
pair of feet. x 135.
Trans. L'poon. Brot. ee Ol, eV bs < Puate I.
A. Scottde/ IZ. With.
COPEPODA.
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er oy te nae
Ly
Tah ad
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=
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os] re
4 ae. 5%
aid
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ie
en a
=
& Ales Z . _
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4 ze ‘
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ae :
et - ent Bahn
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Trans. L’poon. Brot. Soc., Vou. XVI.
Big!
Andrew Scott de/
COPEPODA.
Prats II.
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:
=
COPE PODA
429
fees €. MEMOIRS.
No. IX.). CHONDRUS.
BY
Otto V. DaRBISHIRE,
Owens College, Manchester.
CONTENTS.
AMET TCIM Cocaine cielsneceecvececerscnaveecescaibodccannessseeeatedosass 430
Introductory remarks. The collection of material and
its preparation for the herbarium and the microscope.
PE SvaMMmrUISTORISPUS (1i.)) STACKH. © ......ssccccnccccccesdsecsccerudenss 435
A. External morphology of the vegetative organs ......... 435
B. Anatomy and histology of the vegetative organs ...... 438
HPMEP AMAL OMANOL LIVCrSWOOU Seerseicuernise «ctersivinn svsaineieaiees 438
PPR ANAT ONAN (OL TNC LOOU wacces csc verececics sonseetses<creotes 443
SR ANSFOLOSY Of LO SMOOW. ..ccuo.ccsessaeau te -lacenanvacas 444
PEPELIShOlogy Of HAE TOOL! cose acias aoveeniensieesamscnedeant 448
C. Physiology of the vegetative Organs .............ssseseeees 448
ES ET OOUCTIVE OLGANS os csseuressiesssecieseseveecedessecesace 450
PEALE ATTA ACCUM ppisee cee sues sce sbaas vise csis/ses se =e 451
PEE ENS CUU OP WOLEM ce scaci's oe clolsieee oie sve cierlo omcisdiatusten's 454
DEEPEN CATO MAOEC: sp cccteecece aes oslo onas sa <ciaesaimsnslucvus 455_
RE BONO as reer srerine eran ae tepietivls vnoms cae sive escadva opensuse 457
TMA SCONCLUDING REMARKS .......0.scsccsersscssessesssessssssecesccscovereres 462
Sere G SOIAAA ALTON, ccistoasits ac ealearsina idacacseosssnese overeat eweioes ess 463
POCA IICIOMA sla ca'- «p's doislsieivarssecesvectansussinnes seeiistetesikins vemsoaainy sere 465
DESCRIPTION OF THE PLATES woccsecsserecssoscessevececsccecerersceses 467
HH
430 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
L—INTRODUCTION.
Tue Rhodophycee are a very distinctive class in the
Kuphycee or Algz, which form a sub-division of the
THattopHyta. They are separated from the other classes
of the Euphycee by their reddish or violet colour. This
colour is produced by the green chlorophyll being obscured
by a red colouring matter, called Phycerythrin. The
RHODOPHYCEAZ embrace two sub-classes, namely, the
BanGIaes and the FuoripEm. The representatives of the
former have very simple and undifferentiated. filamentous
or membranous multicellular bodies. ‘The sexual organs
are extremely simple. The Florideze have multicellular
bodies, consisting usually of much-branched rows of cells,
which often form plants of good size and firm structure.
To the sub-class Floridez belongs the subject of this
memoir, Chondrus crispus, the Irish Moss. With the
exception of nine genera, five of which are confined to
freshwater, the Floridee are exclusively marine plants.
The arrangement of the natural orders of the Florideze
into series is dependent on the various methods by which
the fruit develops after the fertilisation of the female
organ. It is unnecessary to refer to the subject in detail
here. It must suffice to say that the natural orders are
arranged in four series, namely, the Nemalionales, the
Gigartinales, the Rhodymeniales and the Cryptonemiales.
The natural order to which Chondrus belongs is that
of the Gigartinacez, one of the Gigartinales. The only
other order of this series, the Acrotylacez, differs from
the Gigartinacez in the arrangement of the asexual spores
in their mothercell. The tetraspores of the latter are
formed by cruciate, those of the former by zonate,
division.
CHONDRUS. A
The natural order Gigartinacee includes nine British
genera, namely, Chondrus, Gigartina, Phyllophora, Steno-
gramme, Gymnogongrus, Ahnfeltia, Actinococcus, Callo-
phyllis and lastly Callymenia. Of these the representa-
tives are all fairly well developed plants, with the excep-
tion of the species belonging to the genus Actenococcus.
One of these has been shown to lead a parasitie life on
Phyllophora Brodie.
The genera Chondrus and Gigartina differ from the
remaining members of the Gigartinaceze in their structure.
They show internally a very well marked hyphal arrange-
ment of the cells—their internal tissues in the younger
plants consisting of fairly loose filamentous cells. The
central tissues of the other genera are, with the exception
of Actinococcus, far more compact and pseudoparenchy-
matous. The species of Chondrus have a flattened plant body
orthallus. The carpospore: in the fruit or cystocarp are not
surrounded by any special fibrous integument. The latter
is one of the distinguishing features of the species of the
genus Gigartina.
Chondrus crispus is the only species of its genus
occurring in British waters, and therefore in the L.M.B.C.
district. Quite a large number of varieties are dis-
tinguished, but I have not referred to these in this memoir,
as I consider their recognition to be of no general value.
The genus Chondrus was founded by Stackhouse—the
name crispus was given to the species by Linneus. The
latter, however, placed the species in the genus Mucus, to
which he referred almost every seaweed. Stackhouse
removed the species, and gave it a place in the genus
Chondrus, where it has remained ever since. Its name
therefore runs thus: Chondrus crispus (L.), Stackh., or,
according to a certain number of German Algologists,
Chondrus crispus, L. sp. They wish to indicate merely
4382 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
the author of the species, the “sp.” in this case implying
that Linnzeus was responsible for the specific name only.
Chondrus crispus grows very plentifully along our sea-
coast, as long as the sea bottom is rocky. It is usually
left dry at low tide, when it can be easily obtained. It
much resembles Gigartina mammillosa, from which plant
it is, however, easily distinguished when in fruit, but not
so easily when sterile. Gzgartina mammillosa nearly
always has the margins of the thallus lobes slightly rolled
in. Chondrus crispus will probably be recognised fairly
well by referring to our Plate I. It should be carefully
separated from Gigartina mamnuillosa, Gymnogongrus nor-
vegicus and Phyllophora membranifolia.
A few remarks may not be out of place here on the
collection of material and its preparation for the herbarium
and the microscope.
All material collected for an examination of the
external morphology or the internal structure should be
gathered fresh. Plants thrown up after a gale are usually
in poor condition. <A glass jar should be taken on every
shore collecting expedition, into which the plants should
be put, immersed in sea water, as soon as they have been
removed from the substratum. The latter can be done
with a knife, or a bit of the rock may be chipped off. The
water in the jar should not be allowed to get too warm.
The height at which the plants were collected should
be noted, also the nature of the substratum, and also
whether the plants were growing exposed on the bare face
of the rock or in pools.
In the laboratory the alge should be kept in a dark,
cool place. It is usually sufficient to put the jars under
the working table. Proper cultures may be set up, and
kept for many years, by putting a few seaweeds in a good
sized jar, keeping the temperature of the water low and
CHONDRUS. 433
exposing only to the feeblest light. To examine the external
morphology of any alga, the specimens should be placed in a
shallow white dish, and again kept covered over with sea water.
Before mounting specimens for the herbarium they
should be soaked for a few minutes in fresh spring water
to remove as much as possible of the common salt present.
The phycerythrin of the Floridexe being soluble in fresh
water, too long an immersion in fresh water would destroy
their colour. After being washed the plant should be put
between sheets of blotting paper, or better, some kind of
filter paper. I find that so-called common German filter
paper answers very well indeed. This paper is very much
tougher than most kinds of blotting paper, and also a
good deal cheaper. A board is put on to the top of the
drying paper, and this is weighted down by a few not too
heavy stones. In the case of certain alge, which are more
delicate than Chondrus crispus, it will be necessary to float
them out in fresh water on to a piece of white foolscap
paper. They will usually be found to stick naturally to
the paper they have been mounted on. To prevent their
sticking to the filter paper some fine muslin is interposed
between them and the drying paper. When the plants
have been pressed for a few days, with a daily change of
the paper and muslin, the weights may be removed for
twelve hours to allow the air to circulate more freely for
drying purposes. All the specimens should be carefully
labelled with the name, locality, date, and any short
remarks which may seem necessary.
To examine any material under the microscope, it
should be cut as fresh as possible, and examined in sea
water. Transverse and longitudinal sections of every part of
the plant should be cut with a razor, with or without
clamping the material in pith. The section should then
be mounted and examined in sea_ water. Fresh
434 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
spring water or glycerine kills the tissues very rapidly,
and the former more particularly causes a great swelling
up of the cell walls, whereby the appearance of the tissues
becomes very much distorted. Jodine should frequently
be employed to test for the presence of starch. For this
purpose dissolve some crystals of potassium iodide and
some of iodine in water.
Permanent preparations may be made by putting a
freshly cut section into dilute glycerine, and thence into
glycerine jelly. Sections may be stained in a solution of
hematoxylin ( 1 per cent. solution in water), and then
mounted in glycerine jelly. When stained, sections can
also be permanently mounted in Canada balsam. To this
end they should, after staining, be dehydrated in absolute
alcohol, and after replacing the alcohol by xylol, they are
mounted in Canada balsam, which has previously been
dissolved in xylol.
If it is intended to preserve some material in a bottle
for future examination, it should be fixed in a 1 per cent.
solution of picric acid in water. The material may remain
in this solution for a few hours, and is then washed in
50 per cent. alcohol, till the latter no longer becomes
yellow. Then remove it to 70 per cent. and finally to
90 per cent. alcohol for preserving. Some glycerine
(about 25 per cent.) may be added, thus preventing the
specimens getting too brittle.
In order to cut sections with the microtome, the portions
of the plant to be cut must be embedded in paraffin. They
should be dehydrated in absolute alcohol, left in cedar-
wood oil till they are quite transparent, and then trans-
ferred to paraffin at 55° C. They may be cast in a block
after about two hours.
Permanent preparations are, however, useless to a
student, if similar sections have not been previously
CHONDRUS. 435
examined in a fresh condition. The student should,
furthermore, make drawings of the sections before they
are permanently mounted. A permanent preparation of
an alga is often a very poor guide to the condition of
things obtaining in the living plant. A good drawing, or
even a careful sketch of a fresh section is at a later date
generally a far better reminder of what was seen in the
living plant than an old glycerine preparation.
It is a useful plan to make the drawings on loose sheets,
and insert them in the herbarium with the dried specimens.
lt is, of course, necessary to carefully label all slides at
once. This prevents any possible confusion to which a
later labelling by memory nearly always leads.
II—CHONDRUS CRISPUS (L.) Sracxn.
The species Chondrus crispus has now been definitely
recognised from the introductory description given in the
preceding part of this memoir. We can therefore proceed
to the more detailed description of the plant.
A.—TuHe ExtTerRnNAL MoRPHOLOGY OF THE
VEGETATIVE ORGANS.
The plant body of Chondrus crispus shows a very dis-
tinct morphological differentiation into two parts—
namely, into a shoot and a root. Nevertheless it is
generally referred to as being a but little differentiated
thallus, the differentiation not being of quite the same
degree and kind which we meet with in the higher plants.
But it is possible to distinguish very clearly a root from
a shoot. The latter alone bears the reproductive organs.
The Roor is mainly an organ of attachment. In this
respect our alga resembles most of the higher aquatic
436 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
plants. The root is a flat and not very thick plate of
tissue, which adheres very closely to the rocky substratum.
No food material apparently is absorbed from the latter.
There is no reason, however, why the exposed portion of
the attachment dise should not extract some food material
from the surrounding sea water. It is coloured a faint
red, and it may therefore assist in the process of assimila-
tion, but only to a limited extent. It is, however, an
important organ for the storage of food material. It
grows in circumference along its margin, covering every-
thing that may happen to be attached to the rock and
extending into any small holes and crevices in the latter,
thereby acquiring a very irregular shape (Pl. IIL, fig. 9).
By this means the whole plant gets very firmly attached to
the sea bottom (see Pl. I.) |
From the flat root disc arise the numerous upright
sHoots. These are at first undivided and more or less
cylindrical in transverse section. But they soon become
flattened, and when they have attained a height of 1°50”
(3 cm.), they are always divided. The full grown shoot
is as a general rule more or less flattened throughout. Its
lowest end, however, just where it joins the root organ,
may be cylindrical, but it soon becomes flattened, even if
only slightly. With its first division the shoot becomes
very much flattened and very thin. The branching of
the leafy portion of the shoot is throughout a very regular
kind of forking. No midrib is formed, the texture of the
shoot being fairly uniform and almost leathery
throughout.
The shape of the separate shoots is very simple and very
uniform amongst the individuals even of very different
localities—be they broad or narrow forms. A fairly long
and undivided stalk can be distinguished from the much
divided frond. In the taller plants, found chiefly at low
CHONDRUS. A437
tide, the stalk is very long and very strong (Pl. L, figs. 1, 2,8).
In the forms found higher up on the seashore, and there-
fore more frequently and longer exposed, the whole plant
is smaller and the stalk proportionately shorter, the frond,
however, is often broader (fig. 4, 5). |
All forms agree in showing a repeated and fairly regular
bifurcation of the frond into flat lobes, which gradually
get broader at their further ends. A small indentation
between two projecting points at the tips of the lobes
indicates where the next bifurcation will take place. The
segments of the frond not only become broader, but also
thinner in texture. The broadening out of the lobes
causes an overlapping of the seginents.
The colour of the frond varies from dark red to, light
pink, and a brownish colour with a dash of pink.
The following are some of the measurements taken on
our plant. The largest specimens gathered at low-water
mark are as much as 1d-l7cm. (6-7") high, with a frond
12°5cm. (5”) across (fig. 1). ‘The stem in such a case
would measure about 15mm (is’') in thickness. At higher
water marks the plants are found in pools only, and not on
the bare rock, as at the lower tide marks. In the former
case they are much smaller in height and grow in very
close, low tufts. They are, however, usually propor-
tionately very broad (fig. 4, 5).
The functions of the shoot are best expressed by the two
words assimilation and reproduction. The shoot probably
is extremely active in absorbing food material from the
surrounding water. This, however, is a point about which
we know practically nothing of a definite nature. It is
very difficult to keep marine plants in culture, because we
do not know what the essential features of the conditions
are which obtain in their natural haunts. Alga may be
kept for a very long time in fairly dark and cool rooms
4388 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
in even small glass jars. As a rule, however, they grow
very slowly and remain sterile, the conditions being pro-
bably very unfavourable.
B.—ANATOMY AND HIsTOLOGY OF THE
VEGETATIVE ORGANS.
1.—Anatomy of the Shoot.
The young upright shoot of Chondrus crispus shows a
differentiation into several tissues, which are, however, not
very easy to separate at the points where they pass into
one another \see Pl. 11.)
The centre is occupied by very much elongated and
comparatively narrow cells (fig.7). These central cells
lead to a tissue further out of shorter and stouter cells,
from which arise the regular rows of external cells, easily
distinguished by their red contents. There is no morpho-
logical differentiation of these tissues such as we get in
the body of a higher, vascular plant—the differentiation
here being of a purely physiological nature. The external
cells, distinguished by their dark red colourimg form the
3)
“assimilating system,” the large stout ones next inside
>)
form the system of “collecting cells,” the central cells
The whole arrangement is
9)
form the “ conducting tissue.
based on the assimilation, collection and conduction of
food. ‘The assimilating cells have been called the cortical
layer, the two other tissues the outer and inner medulla
respectively. We will employ the nomenclature based on
the physiological function of the respective tissues,
although the other terms, cortex, inner and outer medulla,
are equally good. y
The tissues just mentioned are seen at their best and in
their most characteristic condition a short distance behind
CHONDRUS. 439
the youngest part of the shoot. The youngest or most
actively growing part of a shoot is found at the end
furthest away from the basal attachment organ.
A longitudinal section of a young frond should now be
eut at right angles to its surface, and rather near a
median longitudinal line. The material should be fresh
and the sections should be mounted in sea water. These
should be examined first, but others can also be
examined after being mounted in glycerine (50 per cent
solution in water) or glycerme jelly (fig. 7).
The Central Conducting Cells will be found to be elongated
ina longitudinal direction. They are fairly narrow, and they
possess fairly thick walls. The peculiar nature of the
walls becomes very apparent when a section is mounted
and examined in fresh spring water. In this case,
owing to the rapid absorption of water by the cell walls,
the sections rapidly curl up.
This central tissue of much elongated cells resembles
more a strand of interwoven filaments than a close paren-
chymatous tissue. By this Chondrus crispus may, as
already pointed out, be distinguished from the species of
several allied genera. But it has this feature in common
with Gegartina mamillosa. ;
The cells of the conducting tissue are connected with
one another at certain poinis. These points become very
evident if the cell walls of a section have been allowed to
swell up in water or dilute glycerine. The cell walls
encroach on the cell cavity, leaving only a narrow canal
of varying length leading apparently from one cell to
another. A fine wall, which does not swell up, is stretched
across the canal, thus forming a pit, as we find it in the
higher plants. The pit membrane probably allows of the
cytoplasm of one cell communicating with that of the
other. On each side of this pit is a small cap, consisting
440 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
of what appears to be coagulated cytoplasm. The struc-
ture of the pit will be referred to again, when discussing
the histology of the shoot subsequently.
Connected with the central elongated cells of the con-
ducting tissue are the Collecting Cells. These are much
shorter than the central cells, and as we pass further out
they diminish still more in size. They form a rather
closer tissue than the conducting cells, and they are
extensively connected by pits, with or without the above-
mentioned protoplasmic caps, with any of the neighbour-
ing cells they may come into contact with. The nearer
we come to the outside the more regularly do they come
to le in rows. Finally there arise from them the very
regular rows of Assimilating Cells, which run parallel to
one another, but are curved upwards and outwards at a
certain very definite angie with regard to the longitudinal
axis of the whole shoot. The assimilating cells possess
numerous pits, which are however all destitute of caps.
The whole body of Chondrus crispus consists of a com-
plete system of very long and very much branched hyphe.
The assimilating cells form the apical branches of these
hyphe. As a general rule the divisions in these threads
will take place at right angles te the longitudinal axis
of each cell row. But there is evidence to show that some
of the divisions are more or less at right angles to this
direction. Hyphal tissue of this kind has been distinguished
as plectenchyma. The filamentous nature of the tissues
becomes very apparent if the growing point of a frond is
examined in a longitudinal section, when one can see
spreading out in a fan-shaped fashion the hyphe of all the
three tissues (Pl. IL, fig. 6).
In transverse section the cells of a young plant differ
little in appearance from what is seen in longitudinal
section, except that the conducting cells appear rather
CHONDRUS. A441
round, but still slightly oval in outline. In the case of
the flat frond, they are usually elongated in a transverse
direction and parallel to the two flat surfaces. There is
no difference to be noted in the other tissues.
I have already referred to the growing point. It is
that part of the plant where the formation of new cells is
going on most actively, but it is, strictly speaking, not
the only part of the plant which is growing. Cell division
is going on very rapidly in this region, as may be seen by
looking at the size of the cells. The formation of new
cells is, however, not confined to this region, but is also
going on, though probably less rapidly, at the tips of
nearly all the assimilating cell rows. The innermost cells
of these rows gradually become collecting cells, and new
rows of assimilating cells are formed by branching. New
cells may also, though rarely, be formed by short tube-
like cells growing out from older conducting cells. Thus
far the formation of new cells, as part of the process by
which Chondrus crispus grows, has been described.
The growth in lengih of the shoot is brought about by
the cells of the conducting tissue becoming more elongated,
by the collecting cells becoming larger and in the end
passing into conducting tissue, finally by the assimilating
cells gradually passing into the collecting cells and new
assimilating cell rows being formed by the branching of
the older ones.
The cells of the conducting tissue measure about 8-10u
in length at a point about 100u back from the shoot apex,
at further intervals of 100u they increase on the average
to 10-144, 20u, 380-40u, 50u, being finally 80u at
a distance of about 800u from the apex.
The collecting cells, with a measurement of 4-84 in
their longest diameter at a distance of 100u from the
apex, increase at intervals of 100u to 8-10u, 10-12u,
449 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
and 20u. This may be taken as their greatest diameter,
for after this they would be reckoned part of the conduct-
ing tissue.
The assimilating cells vary very little in diameter, being
about 4-6 x 8-44 near the apex, and rarely rising above
8 x 3-4u in the lowest regions just above the basal disc.
Their longest diameter is generally parallel to the longi-
tudinal axis of the whole row of cells.
The increase in thickness of the lower regions of the
shoot is brought about not by the addition of thick layers
of assimilating tissue, as is the case with Phyllophora
Brodiet. The assimilating layer in Chondrus is 20-254
deep in a flat frond of about 850u in thickness, but in a
frond which was 840u thick, the thickness of the assimi-
lating layer was only 25-30u. The increase in thickness
is in fact due to the assimilating cell rows forming new
cells at their tips, whilst their inner cells gradually pass
into the collecting cells, and these gradually pass into the
conducting cells. The increase in thickness is noticeable
in the central tissue only to any extent. It is taking place
here at the expense of the outer layers, which are, how-
ever, continually being renewed by the formation of new
cells at the tips of the rows of assimilating cells.
It is probable that a good deal of sliding of cells occurs
as the growth in length takes place. The increase in
length is probably caused not by the central cells actively
growing in length, but by their being drawn out passively
during the active lateral extension of the assimilating
layer. But frequent longitudinal slits have failed to indi-
cate in what way tension is distributed in the tissues.
The central tissue is very well separated by the
filamentous nature of its constituents in the younger parts
of the shoot, but in older parts it assumes more and more
a pseudoparenchymatous appearance. By this change the
CHONDRUS. 443
tissues become firmer and the shoot, as a whole, is there-
fore much strengthened in these older parts. The walls
of the conducting cells are very much thicker and firmer
in the older part of a shoot than in the younger one.
2.—Anatomy of the Root.
The basal attachment organ, or the root part of the
whole plant, does not-show any differentiation into the
three tissues met with in the shoot. It forms a flat plate
of tissue, from which the upright shoots arise. Its out-
ward form depends entirely on the nature of the sub-
stratum to which it is attached. It is thickest, however,
at the points from which the upright shoots arise, and it
becomes thinner towards its margin. The lower surface
of the attachment organ penetrates into all the numerous
crevices of the rock in order to firmly fix the plant.
The cells nearest the substratum, forming what might
be called the “ Attachment Layer,’ are of very varying
shape, and are very irregularly arranged. Their position
_and shape depend on the varying minute nature of the
substratum. They have thick walls, and form a layer of
cells touching the surface of the rock which may be two
or three cells deep. But in cases where they have pene-
trated into and completely filled out some small hole, they
may form a mass of thick walled cells, connected only by
small but very firm strands of much elongated cells to
the main mass of the root (fig. 9).
The greater mass of the root tissue proper is made up
of very regularly arranged rows of almost square cells,
which run more or less at right angles to the surface of
the whole attachment disc. These rows of cells are, strictly
speaking, always slightly curved. At the point where
a shoot arises they have a convex side turned towards the
lower end of the shoot, passing finally into and adopting
444 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
the curve of the assimilating filaments of the shoot. Then
again, near the periphery of the whole attachment organ,
where the latter is still very thin, the curved rows of cells
have their convex sides turned towards the margin. Seen
in surface view the cell rows are observed to grow out in
a fan-shaped fashion towards the margin.
The growth of the rows of cells is here mainly, if not
exclusively, apical. Transverse divisions in the apical
cells are common, longitudinal at the most extremely rare.
The upright rows of cells will be seen to be completely
undivided (fig. 10).
The whole attachment disc grows in circumference by
the formation of new rows near the margin. But it grows
‘in thickness by the elongation through apical cell forma-
tion of the old cell rows. The cells once formed do not
change their form and size to any great extent, as soon
as they have attained their full size, about 3 to 4 cells
behind the tips of the filaments.
The whole plant is covered by a protective membrane,
which is not very thick in older shoots, but is very
distinct near the apex of a shoot. It becomes a very deep
layer in certain parts of the basal attachment organ. On
either side of the insertion point of an upright shoot, it is
usually very well developed. It is here produced by
successive layers of wall substance being separated off
from the apical cell of each filament (Pl. III., fig. 10).
The cells of the attachment organ are usually full of
starch. They are reddish in colour, but the latter is not
as dark as in the assimilating cells of the upright shoot.
3.—Histology of the Shoot.
The cell walls of the central cells are not very thick
when examined fresh and in sea water (Pl. IL, fig. 8).
They do, however, swell up very much in spring water
CHONDRUS. 445
or in dilute glycerine. One can distinguish three layers
in the cell walls, which are best differentiated in. case of
conducting cells. when a longitudinal section is stained in
hematoxylin and mounted in dilute glycerine.
The middle lamella is seen to be fairly thin, but can
nevertheless be well made out. It is common to all cells.
Each cell is surrounded by a wall, which lies immediately
inside the middle lamella, and does apparently not swell
up very much 11 water. Then follows an innermost layer,
which is in its turn lined by the protoplasm. This layer
shows a very distinct concentric stratification, and is
apparently most affected by fresh water. It swells up
very much indeed.
With regard to the protoplasm inside the cell wall very
little can be said. It consists of the cytoplasm, and con-
tains a roundish nucleus, one or more plastids, starch and
vacuoles. The cyptoplasm never occupies a very large
space of the cell cavity. The latter is usually taken up
by one or more large vacuoles. The cytoplasm of the
larger central cells consists merely of a very fine mem-
brane, which les between the vacuole and the cell wall.
No fine partitions formed by cytoplasmic lamelle can be
seen stretching across the vacuoles.
In the outer collecting, and still more in the assimilating
cells, the cytoplasm appears as a slightly frothy liquid.
Fine lamellz are seen to stretch across the vacuoles. It
must, however, be understood that the frothy appearance
of the cytoplasm so easily seen in many alge affords no
indication as to its ultimate structure, as is so often
supposed.
It has already been mentioned that the large central
conducting cells are in communication with one another
by means of pits. The pit membranes are thin portions
of the wall which do not swell up in water or glycerine.
II
446 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
Their position, therefore, becomes very apparent if we
allow the other portions of the wall to swell up.
The innermost of the three layers, of which the al
wall is composed, does not apparently take any part in the
formation of the pit, except by its being interrupted at
these points.
The large pits of the central conducting cells have on
either side a cap, which is most likely of protoplasmic
origin. The cap is a short cylinder, the one open end of
which (fig. 12, 13) overlies the pit membrane, with which
. it is co-extensive. At its other end the cap is closed, a small
depression being noticed in the centre of the wall. Itis at
this depression that the cytoplasm is most firmly attached to
the cap. This depression corresponds with the thinnest
portion of the pit membrane. In younger cells nearer the
growing point the caps on the sides of the pits in the
central tissue are not so marked. It is from observations
made in. such parts that the protoplasmic origin of the
cylindrical caps is made likely. The sides of the cylinder
are seen to be continuous with cytoplasmic strands. They
seem, in fact, to be hardened portions of the
cytoplasm.
Owing to the complete absence of any hard woody tissue
in the thallus of Chondrus crispus, it seems very probable
that these hard caps have the important function to per-
form of preventing the collapse or closing up of the open-
ing on either side of the pit.
The cells of the collecting tissue usually have smaller
pits, which may or may not be devoid of any cap-like
structures. The pits connecting the assimilating cells are
usually quite unprotected, but nevertheless form clearly
marked thinner portions in the separating cell wall.
The Plastids met with in Chondrus crispus occur in two
different forms, namely, as rhodoplastids and as leuco-
CHONDRUS. 447
plastids. Both these are, however, only modifications of
the same organ.
The Rhodoplastids are best developed in the assimilating
cells (fig. 14, 15). They are seen here to be of a dark red
colour. The red colour is made up of a mixture of chloro-
phyll and phyccerythrin, the latter completely obscuring
the former. The latter may also be extracted by sub-
mersion in fresh water for some time, preferably in warm
water. The plant will remain green, the chlorophyll
being insoluble in water.
The outermost cell of the assimilating filament has a
very small rhodoplastid. The latter is represented by a
very much reduced flat structure, which fits into the outer
end: of the oval shaped cell. The remaining part of the
cell appears colourless. The other assimilating cells
possess very well developed dark red rhodoplastids. They
form here cylindrical plates, which line two or three or
even all the radial walls, and sometimes even the outer
tangential wall. They do not form a closed cylinder, for
they are open along one side. Each cell here contains
only one rhodoplastid.
The Rhodoplastids are well developed in these assimi-
lating cells, but as you pass on to the collecting cells,
they gradually change. The red colour becomes fainter,
they get drawn out and become very finely divided.. When
we get nearer to the conducting celis, the rhodoplastids
have become almost invisible. Very finely divided
narrow strands are seen of a very faint pink colour. These
are the plastids. The fine strands are interrupted here
and there by rather larger and more deeply stained masses.
Finally in the most central of the conducting cells the
finely divided rhodoplastids have disappeared, their place
being taken by small roundish leucoplastids. These are
almost colourless, but often show a very faint greenish
448 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
tint. These leucoplastids, of which a great many are
often found in each cell, have been derived from the
typical rhodoplastid of the assimilating cells.
The Leucoplastids of the conducting cells and the faintly
coloured rhodoplastids of the collecting cells are both very
active in depositing starch. Starch is never noticed in the
assimilating celis.
The starch grains take the form of flattened discs.
They stain brownish when treated with iodine. The
floridean starch is slightly different in its reaction after
treatment with iodine from the starch of the potato, the
grains of which stain blue with iodine.
4.—Histology of the Root.
The histology of the root calls for no special remarks.
The cell walls do not swell up much with fresh water.
The pits also are not of the same large form met with in
the shoot.
The cells of the root are found to be quite full of starch,
which by its presence almost completely obscures the
rhodoplastids. The root organ is clearly red, but the red
plastids are hardly visible. They are apparently finely
divided, consisting of darker red masses, which are con-
nected with one another by faintly coloured strands.
C.—PHYSIOLOGY OF THE VEGETATIVE ORGANS.
Under the heading of Physiology, reference may be
made to the functions of the three tissues of the shoot. It
is, as already mentioned, to their supposed physiological
function that they owe their names.
The Assimilating Cells are obviously correctly named.
Assimilation is conducted by means of the rhodoplastids.
The fixation of carbon dioxide and the subsequent elabora-
tion of complex organic from simple inorganic compounds
Ss lee
CHONDRUS 449
may be assumed to be going on through the activity and
under the influence of the rhodoplastids. Nothing definite
however is known concerning the importance and function
of the phyccerythrin in the rhodoplastid.
The rhodoplastids in the assimilating cells are on the
whole well developed and of a dark red colour. The
apical cells of these assimilating rows have, however, only
a very small rhodoplastid each. This is a general rule,
and it may be due to the fact that these apical cells are
actively growing and dividing.
The substances built up are apparently removed very
rapidly to the next inner cells away from the assimilating
tissue. ‘This latter, at any rate, contains no traceable
quantities of starch. The food substances are in fact pro-
bably collected by the collecting cells from the outer
layers, and are then passed on to the large conducting
cells. They are then stored or passed up or down the
shoot, according to the direction in which any part of the
plant in need of food may draw them.
A certain faint red colour may often be detected in the
finely divided rhodoplastids of the collecting and of the
conducting cells, but it is impossible to say whether it
enables assimilation to bé carried on. In the centre of
the shoot the red colour has disappeared, and in place of
one red rhodoplastid we get numerous very faint green
leucoplastids.
Starch is found very abundantly in the collecting and
in the conducting cells. Both these tissues, therefore,
probably act as storing tissues.
In the root organ the cells are all found to be full of
starch. The root is evidently a very important organ for
the storage of food. It is not likely that assimilation is
going on very actively in the root. The rhodoplastids are
faint in colour and very finely divided.
450 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
The whole structure of Chondrus crispus is very typical
for a water plant. No hard tissues and no special water
conducting cells are found. The plant as a whole is not
able to keep itself upright except when in the water. The
arrangement of the tissues 1s such that the plant is flexible,
but not very elastic. ‘The shoot is bent to and fro by the
waves and the tides, but owing to the substance being very
tough the shoots are very rarely torn off the substratum.
Chondrus crispus, is, in fact, very rarely found in the
entangled masses of seaweed which are thrown on to the
beach after a gale.
D.—TuHeE REPRODUCTIVE ORGANS.
The reproductive organs of Chondrus crispus are fairly
well known.
Vegetative reproduction seems to play practically no
part in the life of marie plants. If it does occur in
isolated cases it certainly plays no important part in the
general biology either of the red alge in particular or the
sea in general. The power of reproduction is, in the case
of Chondrus crispus, confined to special cells or spores.
These may be produced asexually and sexually. In the
former case, they are called “tetraspores.” In the latter
they are known as “carpospores,” which are the ultimate
products of the fusion of the male nucleus of a “ sperma-
tium”’ with the female nucleus of the “egg cell.” This
fusion—or process of fertilisation—has never actually been
observed in our plant, but may safely be assumed
to occur.
The nemathecia, the organs which produce the tetra-
spores, the antheridia giving rise to the spermatia and the
procarpia which harbour the egg cell, are never met with
on the same shoot. It is impossible to say from the
‘
CHONDRUS. 451
observations to hand as yet whether the shoots bearing
different reproductive organs are borne on the same root.
It is highly probable, however, that they are not.
1.—The Nemathecium.
The tetraspores are formed in great numbers in certain
younger portions of the frond. They make their
appearance during the winter months, probably from
December to March. When held to the light shghtly
oval but elongated dark spots may be seen near the apical
and younger portions of the frond. These darker portions
may be accompanied by a slight bulging out of the assimi-
lating layers, but this is never very marked. Hach dark
part is a nemathecium, containing tetraspores (fig. 19).
In a longitudinal or in a transverse section (fig. 20),
through a nemathecium the dark colour of the latter is
‘seen to be due to a dense and rather irregular mass of
small round cells. These may be the finished tetraspores,
or their mother-cells. Hach mother-cell gives rise to four
tetraspores—hence their name.
The whole internal tissue of the nemathecium consists
of irregular rows of cells, which on the one hand join on to
the collecting and a few of the conducting cells, and on —
the other hand pass into the assimilating layers (fig. 21).
It is, however, before they enter the latter that their cells
swell up at the expense of the neighbouring cells, which
have a large store of starch.
When these cells have attained a certain size they
divide into four cells each. They are, in fact, the tetra-
sporangia or mother-cells of the tetraspores (fig. 22). ‘The
original cell-rows are at first easily made out (fig. 21), but
gradually the cells by their growth exert a certain amount
of pressure in all directions and the regularity of the cell
rows is disturbed. ‘The surrounding sterile cells gradually
452, TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
give up all their store of food material, and finally collapse
almost entirely. The tissues never break down entirely,
but they do get fairly loose when the spores escape on
maturity.
The division of the protoplasm in the spore mother-cell
takes place by the formation of several walls, but always
in such a way that the resulting four tetraspores are
arranged either in one plane round a common point, or in
the fashion of a pyramid of four billiard balls, or in two
pairs, the wall separating the two spores of one pair
running at right angles to that of the other pair. The
spores are said to have been formed by cruciate division.
The tetraspore 1s, on its escape, found to be a round,
non-motile and naked reproductive cell, which soon after
its escape is surrounded by a firm cell wall. It contains a
large amount of food material, starch forming an im-
portant constituent of the latter. The protoplasm of the
spore is also seen to include a rhodoplastid. The latter is
rather difficult to make out, owing to the large amount of
starch present. It seems to be of the form met with in
the old cells of the conducting tissue of the shoot. It
consists apparently. of larger and darker portions regularly
distributed just side the cell wall of the spore, and these
are connected by fine strands. Fresh tetraspores, fixed
with iodine, were heated and mounted in glycerine jelly.
They then showed the rhodoplastids—now quite green—
and their ramifications very well.
When it has escaped, the mature tetraspore is probably
able to proceed to germination at once. How soon it starts
and how rapidly it continues to grow in nature it is still
impossible to say. Probably it starts very soon. The
tetraspores have not the appearance of resting spores.
By employing a method, which gave me good results
when applied to the tetraspores of Actinococcus subcu-
CHONDRUS. 453
tanéus, the small parasite living on Phyllophora Brodici,
I was able to germinate some tetraspores of Chondrus
crispus. The latter were dredged near Kiel, in the Baltic,
and sown in a sea-water culture in the Botanical Institute
of that University.
Small portions of parchment paper were first thoroughly
soaked for a lengthy period, up to six hours, in running
water, so as to remove any acid present. The pieces of
parchment were of a size to be conveniently put on to a
glass slide, and covered with a large coverslip for purposes
of microscopical investigation. These strips of paper were
put on to the bottom of small glass troughs2” x 3” x 6”
being a convenient size. The troughs were filled with
fresh filtered sea water, and kept in a cool and fairly dark
place in the Laboratory. For the first two or three weeks
constant attention must be paid to the condition of the
water in the cultures. ‘The water must be removed imme-
diately on the appearance of the slightest milkiness, the
outward sign of bacterial activity in connection with some
dead organism. A number of cultures should always be
set up, as some will always succumb to some adverse
circumstance.
A portion of a fresh frond bearing a nemathecium may
be placed, as soon as obtained, on one of the strips of
parchment in aculture. After a certain time the spores
will be seen to have escaped, and to be lying about on the
parchment... The frond may now be removed, the spores
remaining in the culture.
When the spores begin to germinate the strips of parch-
ment can be put on to slides and be examined with the
microscope. They must be kept supplied with plenty of
fresh sea water, and be guarded against too strong light.
They may not be kept out of the cultures too long. A
coverslip may be employed, but with great caution.
454 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
If the water in the cultures is once quite clear, it only
wants adding to very occasionally.
In the case of Chondrus crispus, I observed that the
tetraspore underwent division without at first growing very
much in bulk (fig. 27, 28). Then, however, after having
formed a small heap of cells, which are all very much
smaller than the original tetraspore, longish filaments
seem to be formed (fig. 29). These consist at first of
unbranched single rows of cells. Finally the commence-
ment of the formation of flat plates has been observed, and
in the end no doubt a normal flat attachment organ is
formed, from which the upright shoots arise. JI have not
however been able to follow out the growth of the
germinating tetraspore to this stage yet.
2.—The Spermophore.
The spermatia or male cells are found on young portions
of the frond. The latter are temporarily modified only
for this purpose. Later on they evidently again take on
the functions and the structure of an ordinary vegetative
shoot. They have been called spermophores (fig. 30. 31).
The spermophores of Chondrus crispus are small and
narrow, slightly flattened leaves. They appear white
owing to the fact that the rhodoplastids of the assimilating
layers are but poorly developed. They are 3-4mm. long
and barely Imm. broad.
The general structure of the spermophore does not differ
from any ordinary young portion of the thallus. The
difference lies in the nature of the last few cells of the -
assimilating filaments. The last two or three cells appear
to be colourless owing to the rhodoplastid, though present,
being very much reduced. These two or three cells
together form an antheridium, or male organ. The last
cell of the row, the spermatangium, gives rise to one
CHONDRUS. 455
spermatium, or male cell. This escapes as a colourless,
small round cell, devoid at first of any cell wall, with a
diameter of 4-5m. It is non-motile. A fragment of a
plastid seems to be present in the spermatium, but this is
not revealed by any appearance of colour.
When the spermatia have escaped they cease developing
any further till they come in contact with the female organ
or carpogonium.
The antheridia form a layer, which extends over almost
the entire surface of the spermophore, hence the white
appearance of the latter. The spermatia are found to be
mature between October and December.
3.—The Carpophore.
The development of the female cell of Chondrus crispus
has not yet been made out properly. The following
account of its development and structure is based, there-
fore, on the few established facts, and on our knowledge
concerning the state of affairs in nearly allied genera.
Certain portions of the upright fronds take on the
function of carpophores, which carry the female organs.
They are first very short, being barely 1-2mm. in length.
In this condition they show various characteristic struc-
tures. The central conducting tissue is seen to consist of
slightly elongated cells filled with starch. These cells are
destined to play an important part later on in the forma-
tion of reproductive cells. In the assimilating layer certain
of the cell rows, instead of carrying out their normal func-
tion, have developed into procarpia, of which the carpo-
gonia form parts. ach procarp consists originally of four
cells (fig. 36). The large basal cell is seen to be con-
tinuous with the collecting cells stem inwards. Further
outwards it is continued into the two intermediate cells,
and finally the one celled carpogonium. This consists of
456 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
a swollen lower portion, which contains the egg cell and
an upper and slightly drawn out part called the tricho-
gyne, which projects beyond the outer limits of the assimi-
lating layers into the surrounding water. The trichogyne
is the receptive organ for the egg cell. The spermatium
becomes attached to the trichogyne, but only in a very
few alge has the fusion of the male nucleus of the sperma-
tium with the female nucleus of the egg cell been
observed (fig. 36).
Shortly before the supposed fertilisation the large basal
cell has a small cell cut off called the auxiliary cell. The
procarp at this point therefore consists of five cells.
After fertilisation the trichogyne is cut off from the
fertilised egg cell by a complete closing up of the passage
between the two divisions of the carpogonium. The tri-
chogyne, now functionless, soon withers away.
The fertilised egg cell—the oospore—now grows out,
and forms a protuberance in a direction towards the
auxiliary cell. This outgrowth is a sporogenous hypha.
Its contents fuse with the contents of the auxiliary cell,
but as far as has been observed in other cases no fusion of
nuclei takes place. The sporogenous hypha has only been
fed by the auxiliary cell. From the auxiliary cell a
number of filaments now grow out. They are, however,
only continuations and branches of the sporogenous hypha
just mentioned, and represent sporogenous hyphe them-
selves. They grow towards the starch-laden collecting
cells. These filaments are long-celled and very thin. In
their course: they form secondary pits with numerous
neighbouring collecting and conducting cells. When they
reach the latter they draw on their large store of food, and
finally give rise to the carpospores. The end cells of short
branches arising from the sporogenous hyphe, or their
last two or three cells give rise each to one carpospore. In
CHONDRUS. 457
the end the carpophore contains a mass of loose carpo-
spores embedded in a mass of exhausted sterile cells. The
mass of carpospores forms the cystocarp.
The mature carpospore is not unlike the mature tetra-
spore. It is roundish, and at first unprovided with a
definite wall, which, however, it very soon acquires. Its
contents are very dense, a large amount of starchy food
being present. The general colour of the carpospore 1s
red. This is due to the presence of a rhodoplastid, which
occurs in a very much divided form.
The whole mass of carpospores forms a fairly large
cystocarp, which causes a very marked bulging out of the
outer assimilating layers of the carpophore. In this way
the latter may be distinguished from a frond bearing
nemathecia.
What the fate of the carpospores is, we do not know.
Presumably they soon germinate, and thus give rise to
new plants.
Our knowledge concerning the development of the
sexual organs of the Rhodophycee is still in a very
unsatisfactory condition. The botanist who wishes to
obtain any definite results in this connection must, how-
ever, live near the sea for a lengthy period, and have a
sufficient amount of time at his disposal to carry out
extensive and careful continuous observations.
E..—Ecouoey.
As a species Chondrus crispus is found to be fairly
widely distributed, being common on the shores of the
northern Atlantic Ocean. It forms one of the commonest
plants on the seashore in the L.M.B.C. distriet—in fact,
along the whole British coast, as long as the substratum
is hard rock and the water is clear. It is a species which
458 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
grows best in the temperate zone. I have no doubt that
the distribution of the species of marine alge depends on
the same factor as that of terrestrial phanerogams. The
limits of the distribution of phanerogamic species as a
rule coincide roughly with isothermal lines. |
The distribution of the plant form represented by
Chondrus crispus in any given small district is dependent
not on the temperature, but on quite different factors. It
is impossible to say as yet fully what these factors are.
The following account is therefore only short.
To begin with, it may be stated that a firm sea bottom
is generally necessary for the growth of alg in general.
Stones which roll about with every tide never bear red or
brown seaweeds, at the most only a few green ones. Sand
is always quite barren.
Certain alge occur very regularly at certain heights
above or below certain fixed levels. I have lately been
fixing these heights for a few alge in Port Erin Bay as a
preliminary to some more detailed investigations into the
vertical distribution of marine alge.
If we call the level of dead low-water mark of an
ordinary spring tide O, then we can divide the shore into
a series of regions. We will begin from the highest point.
Pelvetia canaliculata extends from 12‘to17' above O. These
plants are often left exposed by the sea water for days.
The highest individuals are often moistened only by the
spray of dashing waves.
Fucus vesiculosus extends from 3’ to 13’, but not in the
same condition. In an upper region, 9/ to 13’ above O,
the plants are small, rarely fertile, and possess no vesicles.
In the lower region the plants are normal.
Ascophyllum nodosum extends from 6! to 11’ above O.
Fucus serratus forms a very distinct region, 3! tert
above O.
CHONDRUS. 459
Laurencia pinnatifida begins at about 6’ above O, and is
closely followed by Laminaria digitata, 5' above O. Lami-
naria saccharina begins a few feet lower down. Sacchorhiza
bulbosa and Alaria esculenta still accompanied by Lami-
naria saccharina and digitata, the latter having about
reached its lower limit, are then met with at about
3’ below O. Halidrys siliquosa is found at a still
greater depth.
These are the chief plants met with in descending from
the highest to the lowest water-marks.
The data mentioned so far refer to plants which lie
exposed on the surface of the rock when the tide recedes.
Jt is important to mention this, as many plants rise to a
greater height when growing in pools.
Laminaria digitata may rise to 9' above O, and probably
higher still ina pool. Exposed, however, its upper hmuit
appears to be 4’ lower. The plants at the former heights
are much smaller than those growing exposed lower
down.
We can say that alge exposed when the tide recedes
attain their best development in size and reproductive
powers in the lower part of the region to which they
belong. As they rise to the upper limits they become
smaller. They may, however, be found above their
normal limit in pools. The higher pool plants are always
smaller than the lower exposed ones.
Chondrus crispus, as a plant lying quite exposed when
the tide recedes, extends from 3/ to 4! above O downwards.
It has been actually observed to about 3’ below O. Asa
general rule the upper plants are shorter, broader and
thinner (PI. L., figs. 4,5), than the lower ones. The latter are
stouter, very much longer, and the frond is divided into
narrower lobes than are found higher up. When growing
in pools Chondrus crispus has been found up to a height
460 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
of 9’ above O, being often fairly broad, but never very
-high. It is a plant which is completely exposed only for
a short time. »
Little is known as to the reason why longer and shorter
exposure causes a difference in the habit of an alga. We
practically know nothing about the distribution of and
the meaning of the plant forms met with in alge.
Long submergence in sea water is evidently conducive
to increase in size and strength. This is possibly due to
the necessity of providing for an increase in assimilating
power. The forms which are left exposed long become
smaller and often rather close set. Plants with bladders
are restricted to a limited area, which is probably exposed
at every tide, but the significance of the bladders, from
an ecological point of view, I have not yet been able to
fathom. Halidrys seliquosa occurs, with bladders, quite
isolated, at great depths.
So far it can only be said that marine alge, as a whole,
are at their best when least exposed. Certain species,
however, by the possession of certain structural or other
peculiarities are able to live in localities which must be
considered less favourable. ‘They were driven there by the
strong competition prevailing in better localities. Pelvetia
canaliculata was probably unable to stand the competition
of the moister parts of the sea shore, and was thereby
driven to its present position. Many of the green alge
seem to be at their best in the higher regions. <A large
amount of hght seems to be necessary for their well being.
Many Chlorophycee seem to be quite indifferent to
changes in the salinity of the sea water caused by an
inflow of fresh water. 3
The point of greatest interest is still to ascertain that
factor, the influence of which the plants have to guard
against during exposure. Is it the strong lght, or is it
CHONDRUS. 461
the danger of being dried up? I do not think that the
latter can be very great. Even with a fairly strong wind
and strong and warm sunshine, the large individuals of
Ascophyllum nodosum of the higher regions can hardly be
said to become really dry, when exposed between tides.
The upper exposed side may not be very moist, but the
under side often remains quite wet.
Nevertheless I think it will be found that moisture and
light are the two factors which have a hand in the shaping
of the forms of alge. My preliminary investigations,
carried out over a limited area, and during a short period
only, certainly point to this conclusion.
One remarkable feature in the life of the marine alge
is the way in which the reproductive cells will germinate
apparently anywhere. The presence of a young algal
germling is no indication that the locality is quite
suitable for the adult plant. The reproductive cells are
very easily distributed, and apparently germinate very
readily almost anywhere, at least in a good many cases.
Thus it is that the flora of every locality is a very accurate
expression of what competition and locai conditions have
allowed to flourish. As a rule everything that has a
chance in any locality will be found there.
In this connection reference might be made to a few
plants which I have observed growing on Chondrus
erispus. ‘These are nearly all epiphytes. The only
exception is Mntocladia viridis, a green alga, which I
occasionally found growing apparently parasitically on
our plant, penetrating in between the assimilating cell
rows of the upright shoots.
Some of the very numerous epiphytes met with
belonged to the following species; Rhodymenia
palmata, Asperococcus compressus, Fastigiaria furcellata
and species of Melobesia, Cladophora, Enteromorpha,
KK
462 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
Ceranuum, Polysiphonia, Callithamnion, Dermatocarpon
and others.
Not a few animals are also found on Chondrus crispus.
Flustra grows attached to the fronds, whereas others, like
Caprella linearis, and some of the Halacarini are found
crawling about on the upright shoots.
Chondrus crispus is a perennial plant. The root goes on
crowing for several years, sending up new shoots annually.
Considering the condition of things, which I have observed
in the Baltic species of Phyllophora, I do not think that
a frond once separated from the base can again attach
itself. I have had detached individuals of Phyllophora
membranifolia and P. Brodie. under observation in
cultures continuously for several years. The wound
formed by the separation would gradually heal over,
but no attempt would be made to form a new
attachment organ.
The reproductive organs of Chondrus crispus are formed
during the winter. The reproductive spores probably
germinate in the early summer.
III.—_ CONCLUDING REMARKS.
Having surveyed more or less in detail the develop-
ment, structure and ecology of Chondrus crispus, I will
-now give a brief summary of what has been said in
the preceding chapters. The summary takes the form of
a full diagnosis. A diagnosis may include just enough
information to distinguish any particular species from
nearly allied forms. It is better, however, that it should
include more. It should supply as complete but as brief
an account of the species as possible.
CHONDRUS. 463
p Chondrus crispus (L.) Stackh.
SYNONYMY AND LITERATURE:
Harvey, W. H., Phycologia Britannica. 1846-18951.
Synopsis 197 (plate 63). A full account of the
Synonymy will be found here.
Hauck, F’., Die Meeresalgen Deutschlands und Oester-
reichs, 1885, p. 184.
ILLUSTRATIONS :
Harvey, loc. cit., plate 63 (Syn. 197): generai habit of a
broad and a narrow form; transverse and longitu-
dinal sections of the stem; general view and section
of nemathecia.
Hauck, loc. cit. p. 134, fig. 53: habit of plant with
cystocarpia and nemathecia, with sections of both.
Murray, G., Introduction ‘to the study of seaweeds. 1895.
Plate VI., fig. 3.
Wille, N., Entwickelungsgeschichte der physiologischen
Gewebesysteme bei einigen Florideen. 1887.
Nov. Act. Leop.-Carol. Vol. 52, n. 2. Plate VII.
fig. 70, 71. Anatomical details.
EXxsiccata :
Nearly every published collection,of dried marine alge
contains specimens of this species, so that it is
unnecessary to quote here a lengthy list.
Remarks.—The Synonymy of Chondrus crispus is very
straightforward. Harvey refers to certain repro-
ductive organs, which he calls “ prominent tubercles
(nemathecia),” and which are certainly not
nemathecia in our sense. Nothing in Chondrus
crispus, in fact, corresponds to these prominent
tubercles. Murray refers to the spermatia as
pollinoids. I see no reason why the term sperma-
tium should be replaced by pollinoid, especially as
464 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
it has nothing whatever to do with the pollen grain.
The forms and varieties mentioned here and there
in the literature are of no special value.
DIAGNOSIS:
Thallus, consisting of root and shoot. Root, a flat, hard,
reddish disc of irregular outline, made up of very
regularly arranged ‘cells of very uniform size and shape.
Shoot, upright, 15-1l7em. high; narrow or slightly
flattened stalk; frond repeatedly forked and divided into
very much flattened and thin lobes; internal conducting
cells elongated, loose, hyphal in younger parts; more
external and small collecting cells leading into external
rows of assimilating cells, each containing one rhodo-
plastid.
Nemathecia, slightly prominent dark red spots on young
lobes; sporangia in rows; tetraspores roundish, formed by
cruciate division; mature December to March; in ger-
mination the spores divide into a number of cells before
increasing in bulk.
Spermophores, small, narrow, white leaves on apical
margins of frond; antheridia formed by two or three
outer cells of assimilating layer; spermatangia produce
one spermatium each. Mature October to December.
Carpophores, small leaflets on frond; procarpia just
inside assimilating layer; basal cell, cutting off auxiliary
cell before fertilisation, two intermediate cells, carpo-
gonium and trichogyne; sporogenous hypha of egg cell
fuses with cytoplasm of auxiliary cell, and numerous
sporogenous hyphz grow out towards the central starch-
laden cells of the carpophore, fusing with them and pro-
ducing carpospores; cystocarps forming prominent dark
red patches on the frond; ‘carpospores roundish. Mature
December to March.
Oe a a a
CHONDRUS. 465
Hasrrat.—Rocky sea bottom, in clear water, very rarely
epiphytic on other alge; low-water mark. Very common
in the district.
Distrrpution.—Atlantic shores of northern hemi-
sphere.
Kconomics.—lt might be mentioned here—although the
point is of no interest botanically—that Chondrus crispus
was formerly often used, and—I am credibly informed—
is still occasionally used, in the making of jellies. It is
known as Irish Moss, or carragheen, by chemists, and was
supposed to be useful against consumption.
In Concuuston, I would like to say that it is most im-
portant that the student, who has worked through
Chondrus crispus, should examine a number of other red
algee.
If staying near the seaside, seaweeds should be collected
and carefully examined. Drawings should be made of a
few anatomical details and of the reproductive organs.
An attempt should be made to name the specimens
collected. It may often be impossible fot the beginner to
determine the species, and he must be content if he can
- ascertain the genus to which it belongs. If he also fails
in the latter, the material, together with the drawings,
should be laid aside for future reference.
Unfortunately we are very badly off at present for any
book on the British Alge. The very good Phycologia
Britannica of Harvey was published in 1871, and is there-
fore very much out of date. Its illustrations are, however,
as a rule very good, and the student can use it as a
beginning. But many of the generic and specific names
have changed since 1871, and a very large number of new
species have been added to our flora.
466 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
A British Marine Flora is being compiled, but no date
for its appearance has, I have been kindly informed, as
yet been fixed by its author.
The works by Murray and Hauck quoted above may be
of some help, especially the former, although it treats of
foreign as well as British marine alge. It contains a
short list of books and atlases of algological interest.
Vol. I., part 2, of Engler and Prantl’s “ Die Natitirlichen
Pflanzenfamilien,’’ which treats of the alge, is a very
useful book to consult. By the aid of this the beginner
may often be able to determine the genera.
Fig.
Fig.
Fig.
Fig.
Fig.
Fig.
Fig.
Fig.
i.
HH co v9
CHONDRUS. 467
DESCRIPTION OF THE PLATES.
Puats I.: Ture Generar Hast.
A typical form of low-water mark.
Narrow form, low-water mark.
Broad form, low-water mark.
and 5. Broad forms, high-water mark.
All these specimens, drawn natural size,
were collected in Port Erin Bay, between the
16th and 19th of May, 1901.
Puatse I].: ANATOMY OF THE SHOOT.
Longitudinal section of frond apex, mounted in
glycerine jelly. x 390.
Longitudinal section of a young frond a short
distance from apex, mounted in glycerine jelly.
x 190.
Longitudinal section of older part of frond,
examined in fresh sea water. x 390.
Puate Ill.: Anatomy or tHe Roor.
Perpendicular section through the root and the
insertion of two upright shoots. The central
tissue of the latter is seen to end in the attach-
ment organ in a conical form. ‘The root has
attached itself to the rock by anchorlike out-
growths. x 04.
. 10. Perpendicular section through the upper layers
of the attachment organ mounted in glycerine
jelly. Notice the regular and unbranched cell
rows, and the series of caps which have been cut
off by the tip of each row towards the surface,
x 1075.
Fig.
Fig.
Fig.
Fig.
TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
toe de
12.
14.
15.
iG!
Aalyie
pep Lo:
Section in the same direction of the regular cell
rows of the inner tissue of the root, mounted in
glycerine jelly. x 1075.
Pratt LV.: Huistotocy or THE SHooT.
A central cell from the longitudinal section of
an old shoot, stained with hematoxylin,
mounted in glycerine jelly. The middle
lamella, the darker portion of the cell wall,
which has not swollen up, and the lighter and
stratified inner cell wall, which has swollen up,
may be distinguished. x 1075.
Large pit between two central cells in optical
section; on the left the same in end view.
Mounted in glycerine jelly. x about 3000.
The apical (smaller) and next inner cell of an
assimilating cell row. The former has a
smaller rhodoplastid than the latter. Fresh
material. x about 4000.
Transverse section across an inner assimilating
cell. The rhodoplastid lines the wall. Fresh
material. xabout 4000.
The much-divided rhodoplastid of an inner
collecting cell. Starch is being formed here
and there. Fresh material. x about 4000.
Leucoplastid from a conducting cell. Fresh
material. x about 3000.
Starch grain, seen from its broadest (a) anu its
narrowest side (6). Examined in iodine .and
glycerine. xabout 3000. L
Puate V.: THe NEMATHECIUM.
Habit of a plant bearing nemathecia. x 2.
Vith.
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“B.C. Memoir IX.
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B.C. Memoir IX.
CHONDRUS.
ANATOMY OF THE Root.
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CHONDRUS. 469
Longitudinal section of a frond containing a
nemathecium. x 43.
Section showing the undivided spore mother-
cells lying in rows, which are continued into
the assimilating filaments. Fresh material.
x 1075.
Mass of divided tetrasporangia, surrounded by
the sterile cells in a nemathecium. Fresh
material. x 1075. -
Form of cruciate division of a sporangium.
Diagrammatic.
Another form of the same. Diagrammatic.
Another form of the same. Diagrammatic.
Single free tetraspore. It is filled with food
material; the darker portions represent parts
of the much divided rhodoplastid. x about
3000.
PLATE VI.: Tur NEMATHECIUM AND THE
LL
SPERMOPHORE.
Free tetraspore, some time after its escape, and
surrounded by a wall. In elycerine jelly x 1075.
A tetraspore, having germinated to four cells.
In glycerine jelly. x 1075.
Germinal product of a tetraspore forming a
rhizoid-like outgrowth. In glycerine jelly.
x 1075.
Frond bearing spermophore at its tips. x 2.
Two spermophores. x 12.
Outer layers of the tissue of a spermophore.
The assimilating cell rows end in antheridia.
The last cell of each antheridium, the sperma-
tangium, gives rise to one spermatium. In
glycerine jelly. x 1075.
Fig.
TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
: ed.
Puatse VII.: Tue CAarPoPHore.
Frond bearing several cystocarps. x 2.
Longitudinal section of a carpophore, showing
the spore mass of the cystocarp bulging out.
x 43.
Group of carpospores surrounded by numerous
sterile cells. The two lowest are shown with
dark spots, which represent portions of the
finely divided rhodoplastid. x 1075.
Diagrammatic view of the procarp. The single
arrow line shows the sporogenous hypha grow-
ing out from the fertilised egg cell. The three
arrow lines indicate the course adopted by the
several sporogenous hyphe growing out from
the auxiliary cell towards the nourishing cells
of the centre of the carpophore.
471
SNAKE - VENOMS.
By W. Hanna, M.A., M.B.
[Read April 11th, 1902.]
Venomous snakes are pretty well distributed all over
the temperate and tropical regions of the world, with the
exception of New Zealand and Oceanic Islands. They are
divided into two great classes : —
1. Poisonous colubrine snakes.
2. Viperine snakes.
~The chief aim of the paper is to draw attention to the
differences in the two great classes, especially as regards
the poison apparatus, and more particularly the venom.
The two types to be considered are the cobra, represent-
ing the colubrine, and the daboia, or Russell’s viper, repre-
senting the viperine snakes, these being the two snakes
with which the writer has more intimate acquaintance.
The venom of snakes is secreted in a gland which is the
homologue of the parotid salivary gland in other
vertebrates. It is a compound racemose gland with large
alveoli. These have an epithelium of short columnar cells
enclosing a capacious lumen, in which the secretion is
stored. The glands are placed one on each side of the
head, behind the orbit and beneath the masseter muscle.
In the cobra they are of very large size. The poison duct
passes from the anterior margin of the gland forwards
along the upper jaw; it is longitudinally folded on itself
for the greater part of its length, and lined with
epithelium.
The duct has opening into it, throughout its length, a
series of small glands, completely surrounding it. It has
A472, TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
been supposed that in the cobra these small lobules are
mucus glands. ‘Thus in the Ophidia are to be found the
only animals in which an admixture of mucus is present
in the parotid saliva.
Before reaching its termination the duct doubles on
itself, and opens upon a small papilla on the anterior wall
of the mucous sheath surrounding the base of the tooth.
The fang is attached to the maxilla, is tubular and
slightly curved. The canal for the poison is really on the
outside of the tooth, being formed by the longitudinal
reflection of the margins of a fang, which has, as it were,
been flattened out transversely.
It has two openings. The basal one, near the papilla of
the duct, is on the anterior surface; the other opening is
on the same surface of the tooth within a short distance of
the point.
In the largest specimens of the cobra, the fang does not
often exceed 4in. In the viper it is much longer and
beautifully curved, but never exceeds 4in. in length.
In the vipers the fang is so long that it cannot, as in the
cobra, be received into a pit in ihe lower lip. Complete
depression, when the mouth is closed, is therefore brought
about by a slip of the ecto-pterygoid muscle which passes -
to the mucous sheath surrounding the fang.
When the snake opens its mouth the fangs are erected. .
This takes place to a greater or less’ extent in. different
snakes. The sheath of the fang is drawn tightly over the
anterior surface, and the aperture of the poison duct and
the opening at the base of the fang are brought into
apposition. |
The muscles acting in the closing of the jaws are the
masseters and internal pterygoids. The masseters have
some of their fibres inserted into the tough fibrous capsule
of the poison gland, and when contraction of the muscle
SNAKE-VENOMS. 473
eecurs the gland is compressed and the poison dis-
charged. |
By the arrangement of folds of mucous membrane round
the base of the tooth, as is well seen in the sea snakes
(Hydrophide), and especially in the cobra and viper, any
injury or loss of the fang does not affect the apparatus for
the transmission of the poison to the new tooth.
Regarding the rate at which the venom is discharged, it
has been found by Nicholson that a cobra could not eject
through the fang with more force than would be necessary
to expel one drop in three seconds, so fine is the interior
orifice ; a viper, on the other hand, can eject much larger
quantities. The orifice is larger and the poison not nearly
so viscid as cobra poison. The writer has seen a specimen ~
of Russell’s viper, when much irritated, ejects a fine stream
of poison to a distance of several feet.
The poison, then, in cases of snake bite, is discharged
through the duct by the mechanical pressure of the
muscles which lie in the neighbourhood of the gland, and
are used in closing the jaws. Cases, however, are known
where the poison has been discharged reflexly from simple
pressure on the fang. The gentleman who was the writer's
co-worker in India was one day cleansing the mucus from
the mouth of a cobra, which was being held by a snake
charmer, preparatory to expressing the poison, when he
inadvertently pusned the top of his thumb against the
fang. He fancied that as the cobra had not bitten him
he had not received any poison, although the fang had
penetrated deeply; he did no more, therefore, than suck
the wound. In about two hours he had weakness of the
limbs, drowsiness, vomiting, and was unable to feel in his
thumb and first two and a half fingers. The parts swelled,
and it was only after a considerable time that he recovered
by energetic treatment with Calmette’s antivenine. He
474 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
ultimately lost the tip of his thumb as a result of necrosis
and death of ihe tissues. Here, without doubt, a con-
siderable amount of poison had been injected, simply by
reflex contraction of the muscles from pressure on the tip
of the fang.
A few words might be said regarding the keeping of
snakes and taking their poison.
The snakes were usually brought in by snake charmers
during the early part of the rainy season. Later, the grass
grows so long that they have difficulty in obtaining them
in quantity, and at times they were scarcely obtainable
from the neighbourhood of Bombay, either through the
grass in the jungles being long or the proverbial laziness
of the native, who promises, but never performs much.
The snakes were kept in wire cages, or biscuit boxes
with wire netting over the front and a door at the back.
Snakes have been kept for over a year in this fashion.
The snake charmer came once a week or ten days to feed
the snakes. His method of procedure was as follows : —
Having shaken or pulled the snake, be it cobra or viper,
out of the box to the ground, he allows it to make off, and
following, he grasps its tail with his left hand and elevates
it, so that the snake is unable to turn upon him—it simply
hisses loudly.
He allows it to steady its head on the ground, and while
so doing he gently and firmly places a strong, slender
stick across its neck, pinning its head to the ground. He
now lowers his left hand, and places the tail under his
naked left foot, and with the left hand grasps the neck
firmly close to the head, the stick keeping the head steady
until he has accomplished his object. By taking the tail
in his right hand, he has now complete control of the snake.
His first object is to take poison from the snake. After
washing the mouth (if mucus or dirt is present) with a fine
SNAKE-VENOMS. A475
stream of water from a wash bottle, the snake man, steady-
ing the tail under his toes, compresses the poison glands
gently and gradually with the thumb and forefinger of his
right hand. The poison is forced along the ducts, and
issues from the mouth in drops; these are received into a
clean watch glass held underneath.
Cobra venom comes out much more slowly than that of
the viper, the poison of the latter being of a more watery
consistence. A rather different method is adopted in
taking that of the viper, the fangs being so long and the
sheaths large, much of the poison would be lost. In the
viper, then, a fine piece of string 1s passed round the fangs ;
they are drawn forwards, and made to rest inside a watch
glass, which has been put into the mouth. The glands
are then compressed in the usual way.
Regarding the quantity of poison obtained, a fresh, full-
grown cobra will give from 10 to 20 drops of poison. A
large specimen will give 25 to 28 drops, the quantity being
greatest in wet weather; in captivity, however, the amount
gradually diminishes, and is reduced to 5 to 10 drops. <A
viper will give about 8 to 10 drops of venom when freshly
caught. After the poison has been obtained the snake is
fed. This is done by means of a small glass funnel passed
into the mouth. The snakes were fed each on one egg
beaten up in a little water. Snakes kept in captivity in
Bombay—and there were about 40 of them at the Govern-
ment Research Laboratory—invariably refused to bite any
small animal introduced into their cages. They have
been given small rats and toads, and although these, their
natural food, have run and dashed about over their bodies,
they have done nothing’ more than, at times, to hiss
loudly.
Vipers and cobras in the Museum in Bombay always
killed rats and toads. The only explanation is that we
476 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
probably fed our animals too well. I cannot say that they
were overfed.
The venom obtained from the snake was in the cobra of
a pale straw colour; it is of a sticky and gummy con-
sistence. The venom of the viper is more watery, and not
so yellow.
Snake venoms are acid in reaction, and that of the cobra
is said to have a bitter taste. T’he amount of solids varies
from 12 to 60 per cent., according to the condition of the
snake. T’o keep snake venom, it is necessary to dry it
thoroughly, and keep it so. This was done by placing the
watch glass containing the venom in a drying chamber of
calcium chloride. In twenty-four hours it has usually
dried after the fashion of a gum or resin, the film cracking
in the same manner; in some cases a pseudo-crystalline
structure may be made out. Cobra venom dries into small
irregular lumps, or scales, like a resin or gum, while viper
venom gives rise to needle-like pieces, all radiating from
the centre of the mass in the watch glass. Venom, after
drying, can be readily stored in sealed glass tubes. In
these it can be kept almost indefinitely. Professor Weir
Mitchell kept some crotalus venom in his possession for
22 years without apparent diminution in toxic power.
Solutions of venom in glycerine also keep well, but
those in water rapidly deteriorate.
It has long been known that snake venoms contain proteid
bodies in solution, but Weir Mitchell was the first to
demonstrate that the toxic properties of crotalus venom ~
resided in these albuminous bodies.
It is rather a difficult thing to classify these bodies, this
being determined by their solubility in water, or dilute
saline solutions, coagulation by heat, or precipitation by
alcohol. From their retaining their solubility after pro-
longed sojourn under alcohol, and the fact that they
SNAKE-VENOMS. . A777
require complete saturation with neutral salts to precipitate
them from their solutions, these bodies may probably be
classed amongst the albumoses.
When a solution of venom is raised to between 70° and
80° C., in the case of cobra and viper poison a white,
flocculent precipitate appears. After removal of this
precipitate the solution is still, in the case of the cobra,
almost as deadly as before the application of heat. Viper
poison, however, loses almost all its texic power, thus
showing how extremely sensitive viper poisons are ito heat
when in solution. The degree of heat and the length of
time of exposure being important factors, the effect
produced also appears to depend on the concentration of
the solution heaited.
From experiments made by Captain Lamb, I.M.S., and
the writer, on the amount of coagulable proteid in cobra
and viper venom, it would appear that cobra venom
contains practically the same amount of proteids coagulable
by heat as daboia poison contains, namely, 25 per cent.
As regards cobra venom, the estimation was widely
different from that obtained by Weir Mitchell and
Reichert, who state that cobra venom contains only 1°70
per cent, of proteid coagulated by heat. Regarding
daboia, there is no record of any estimation to be found in
the literature of the subject; its amount, however, is much
the same as the quantity of coagulable proteid in crotalus
venom, namely, 24°6 per cent.
We might now contrast the symptoms occurring in
persons who have been bitten.
The cobra has a poison fatal to almost all vertebrate
animals. The mongoose, about whose immunity so much
has been written, if fairly bitten by a cobra, most certainly
dies. His long, wire-lke hair and agile movements,
however, protect him almost completely.
A78 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
The symptoms of cobra bite in man are a burning
sensation at the seat of the bite; the spot becomes red and
swollen, and the pain and tenderness may extend. After
one-half to one hour the patient begins to feel weak in the
legs, and lethargic; profuse salivation and inability to
speak and swallow occur; nausea and vomiting are
frequent. Paralysis then becomes general, and the
patient’s breathing gets slower and more laboured,
gradually diminishing until death takes place, with or
without convulsions. The patient may die in from two
to three hours.
Bites from daboia, or Russell’s viper, affect the patient
quite differently. The pain in the wound is exceedingly
severe, followed by swelling and discolouration, much
hemorrhage occurring at the site of the bite. Later the
constitutional effects appear. These consist in great pros-
tration, staggering gait, cold and clammy skin, and
vomiting; convulsions frequently occur, and the patient
may die in about twelve hours after the bite.
If he recover from the general symptoms, the local
effects of the bite continue to be prominent, much more so
than in cobra poisoning. Swelling and discolouration
continue, and the parts may become gangrenous, and the
patient lose a portion of the limb which has been bitten.
Hemorrhagic discharges from the lungs, nose and mouth
are also quite common in viper poisoning.
To give an idea of the extreme toxic action of these
poisons, it has been estimated by Fraser that the minimum
fatal dose for a man is about 30 mgrms., and a full-sized
cobra, according to Calmette, is capable of injeadting at
each bite a quantity of venom which in the dry state
amounts to 30°45 mgrms.
A full-grown rabbit will succumb to about ‘8 mgrm. of
this poison, and a rat to ‘(04 mgrm.
SNAKE-VENOMS. 479
Regarding daboia poison, we have no evidence as yet of
the amount causing a fatal issue in man, but from
observations made in India, Captain Lamb and the writer
concluded that one part by weight per million of
circulating blood was quite sufficient to clot it solid in a
few minutes.
_ The physiological action of the venoms of most of the
poisonous snakes has been much elucidated of late years.
Thus Weir Mitchell, in America, has carefully investi-
gated the nature and action of the venom of the rattle-
snake. The Australian black snake and tiger snake have
been similarly investigated by Martin, of Melbourne,
Wall, Cunningham, Kanthack, Stephens and Meyers have
all added work on the subject of these venoms.
Less recent observers, such as Brunton and Fayrer, seem
to have regarded the physiological action of cobra venom
as identical with that of viper poison. All recent
investigators, however, have shown beyond doubt that the
toxic effects of cobra venom are quite different from the
effects of the venom of true vipers.
Calmette has also recently stated that snake venoms
differ from one another only in the degree of their toxicity,
and that they are all of the same nature. On examining
the literature of the subject, it would appear that although
the accounts of the symptoms produced coincide, yet there
is a divergence of opinion as to the cause of these.
Most writers agree that the action of cobra venom is
chiefly on the central nervous system; yet Cunningham
contends that it acts primarily as a blood poison, the action
on the nervous system being secondary.
Regarding the cause of death in viperine poisoning,
Martin, who worked with the black snake and tiger snake,
believes that all rapid deaths from bites of these snakes
are due to extensive clotting in the blood vessels.
480 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
~ These snakes, however, classed morphologically amongst
the colubrine snakes, resemble the vipers as regards the
nature and action of their poison. Weir Mitchell, as the
result of experiments with crotalas venom, upholds this
opinion. Cunningham, however, working with the poison
of daboia, or Russell’s viper, puts forward the opinion that —
rapid death from the bite of this snake is due to its direct
action on the central nervous system.
From the fact that Martin used the venom of snakes
which are not true vipers, and whose poison, he admits, is
probably related in physiological action to that of the
cobra and also the viper, Captain Lamb, I.M.S., and the
writer undertook some experiments with the venom of a
true viper, viz., daboia, or Russell’s viper. As a result
of these observations it would appear that when death
rapidly follows an injection of viper venom, made
either subcutaneously or directly into the blood stream
(the fang of a snake frequentiy enters a large vein when
a person is bitten), more or less extensive intravascular
clotting is always found on careful examination
immediately after death. Further, it would appear that
even when a dose of poison, which just fails to cause this
clotting, is injected, very slight symptoms, or none at all,
appear. In certain cases, however, where the venom has
been introduced subcutaneously in a small dose which fails
to cause coagulation, serious symptoms of chronic intoxica-
tion, or even death, may arise leter.
The question evidently resolves itself into the considera-
tion as to whether the intravascular clotting, which is
present in all cases, can explain the symptoms observed
and the rapidly fatal issue.
The objective symptoms following coagulation in the
pulmonary arteries, or their main branches, are well
known, and there can be no doubt that the extensive intra-
SNAKE-VEN)MS. 481
vascular clotting, especially in the pulmonary arteries, is
the cause of the symptoms and rapid death in the acute
cases of viper poisoning.
From a study of Cunningham’s paper, it will be seen
that he based his opinion solely on the interpretation of
symptoms, and his examinations were quite inadequate.
It is evident, then, that Cunningham did not observe, or
put no value on, the clotting which has such an important
bearing on the question.
Regarding the cases of viper poisoning in which a fatal
issue is delayed, or in which even after grave symptoms
have developed, recovery takes place, we may divide the
symptoms into local and general.
At the site, a few hours after the bite, a more or less
extensive subcutaneous hemorrhage has developed.
Around this there is a considerable exudation of serous
fluid. In other cases the patient may die rapidly from
spreading gangrene. The patient is dull, depressed,
refuses food, and the skin is cold. No-convulsions or
paralyses occur. The coagulability of the blood is
markedly diminished, and may remain so for some time;
in cases of death it may absolutely refuse to clot.:
The diminution in coagulability of the blood is no doubt
the chief factor in the causation of the symptoms in chronic
‘eases of daboia poisoning, especially of the hemorrhages
and serous infiltrations, and if this deficiency be at all
prolonged, the more likely will the case have a fatal issue.
This aspect of the action is in marked contrast to the
increased. coagulability due to the rapid absorption of
large quantities, and resulting in rapid death from
asphyxia, due to clots in the pulmonary vessels.
The manner in which this diminution of blood
coagulability is brought about is a problem which has not
yet been solved.
482 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
In cobra poison, on the other hand, we have a venom
which would appear to exert little effect on the blood.
Marked diminution of cardiac activity is characteristic of
all kinds of snake poisoning, except in the case of cobra
bite, in which case the circulatory mechanism is not
markedly affected unless the dose be very large.
The principal action of cobra venom on the nervous
system consists in an extinction of function, extending
from below upwards, of the various nerve centres consti-
tuting the cerebro-spinal system, and though no doubt
other parts of the nervous system suffer, cobra poison has
a special affinity for the respiratory centre.
Having shown that these two poisons, cobra and daboia,
are quite distinct in their primary action, and that the
only physiological action of daboia venom is its action on
the blood, especially on the blood coagulability, it may be
now asked, whether this viper venom contains any of the
elements to which cobra poison owes its toxic power.
From the result of observations in India, it seems conclu-
sive that daboia venom is free from, or contains only the
merest trace of, the principal toxic constituent of cobra
venom.
It is now well known, after the work of Calmette and _
Fraser, that the serum of an animal immunised against
cobra poison will protect not only against this posion, but
against the poison of other snakes. This, however, is only
true to a limited extent. There is one poison, viz.,
that of Russell’s viper, which had been shown by
Cunningham and Wall to have a different physiological
action from that of cobra venom; and Kanthack pointed
out that therefore one could hardly expect animals
immunised against cobra poison to become resistant, and
furnish a serum against viper poison.
Captain Lamb and the writer last year, in a communica-
SNAKE-VENOMS. 483
tion to the “ Lancet,’ showed that Calmette’s serum,
obtained from horses, gradually immunised with cobra
venom, furnished a serum of fairly high neutralising
value, viz., that 1 c.c. of the fresh serum was able to
neutralise ‘73 mgrm. of dried cobra venom, and, further,
it was shown that ‘this anti-venomous serum undergoes
progressive and rapid deterioration when stored in hot
climates. Some further work on daboia poison showed
also that Calmette’s serum was absolutely useless
in cases of viper poisoning, 4 cc. not neutralising
even such a small quantity as 125 merm. of dried
viper poison.
Of considerable interest is the question of the natural
immunity of venomous and other snakes to these poisons.
Fraser explains this immunity as due to snakes swallowing
their own poison. Kanthack, however, was unable to
obtain antitoxic effects from the serum obtained from fresh
cobras. Cunningham has since confirmed this, and added
that “the natural immunity of cobras is perfectly distinct
“in its nature from the artificial immunity established as
“the result of continued treatment with snake venom, and
“is unconnected with any material of the nature of an
“ antitoxin.”
Although the serum of the cobra has no neutralising
power against daboia venom, yet the cobra possesses great
immunity against the bite of this viper. Many innocent
snakes are also resistant to cobra bite.
That inoculation of a cobra with its own venom does not
lead to neutralising bodies being produced in its blood has
been shown by Cunningham, and this investigator !s
inclined to believe that the degree of susceptibility runs
parallel with that of respiratory requirement, Batrachia,
which have a low respiratory requirement, being relatively
insusceptible,
_ = ~ “— ia é <
Say a bey, oN re an
Ld ‘ word a <
é » 77 ye ae ie : AAs
a el — ag iy
‘ us iy
i > ie
yur
Self-immunisation, then, does not seem to gin
that natural immunity to their own venoms which -
fs a?
amongst the poisonous snakes.
485
THE PLACE OF GEOLOGY IN ECONOMICS AND
EDUCATION.
By Prof. C. Larworrnu, F.R.S.
[Read December 13th, 1901.]
Your distinguished and enthusiastic member, Professor
Herdman, wrote to me some months ago, giving me an
account of the aims and functions of this Biological
Society, and invited me to come to Liverpool and give you
a “talk” upon some geological subject. This year I have
been exceptionally busy with extra duties and responsi-
bilities, and while I felt I could not possibly decline the
request so kindly conveyed, I begged my friends, Prof.
Herdman and Mr. Lomas, to defer my visit as long as
they possibly could, in the hope that I might find time
to prepare something more than a crude geological “ talk,”
but that I have found to be impossible.
I learn from our Principal, Dr. Oliver Lodge—for the
gift of whom Birmingham University owes Liverpool an
especial debt of gratitude—that you are very desirous of
giving Geology its natural and proper position as one of
the great sciences taught to the Degree students in
Liverpool College, and that you hope to give the subject
eventually the dignity and status of a Professoriate. With
this movement I have naturally the deepest sympathy,
and shall be pleased to aid it by any means in my power.
With this in my mind, I suggested to Prof. Herdman
that it might perhaps best accord with the wishes of the
Society if I spoke upon “The Place of Geology in
Education and Feonomics,”’ and Prof. Herdman, in his
turn, being not only scientific but practical, hinted that in
MM
486 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
this age and in this district the economic side of the
science naturally possesses the widest interest.
Indeed, at a meeting of Biologists lke the present, there
is no necessity for making a defence of, or an apology for,
the science of Geology, or to claim for it its natural place
and status in any University curriculum, side by side with
the science of Biology. Biology and Geology are sisters,
and have long been mutual helpers, and it is almost
impossible to say which of the two has most benefited
by the progress of the other.
The great biological ideas of evolution in general, of
the doctrine of descent, of the survival of the fittest, of the
origin and meaning of the great biological regions of the
globe, even the prevalent biological opinions of the present
days respecting the origin of man himself, are all of them
the natural consequences of the great discoveries made by
geological science. Without the results arrived at by the
geologist, and the proofs of the uninterrupted geological
evolution of the past lands and waters of the globe, pre-
senting the collection and classification of the fossilized
remains of various assemblages of living beings which
have successively peopled them, these great biological
conceptions might well have originated as intellectual
theories, but they would for ever have remained figments
of the imagination—reasonable it may be in themselves,
but wholly incapable of proof.
The whole science of biology has attained through
geology a grandeur cr an immensity undreamt of by the
most sanguine of our forefathers. As the discoveries of
astronomers have proved that the laws which prevail in
this little world of ours rule in all directions through a
universe of worlds, as far as man’s powers can grasp in an
infinity of space, so the discoveries of geology and
paleontology have shown us that the laws and principles
GEOLOGY IN ECONOMICS AND EDUCATION. 487
that rule the biology of the present, have prevailed
unbroken from the dawn of existence through what has
been termed “half an eternity of time.” But on the
other hand, 1t is equally impossible to over-estimate the
benefits which geology owes to biology.
The original biological demonstrations of the Italians,
Steno and Moro, made about the year 1740, that the fossil
fishes found in the Tertiary beds of Italy agreed in struc-
ture with the living fishes of the Mediterranean, and that
their skeletal structures showed that they must have once
been living beings which inhabited a vanished sea, formed
the first of those immovable logical foundation-stones
upon which the great science of historical geology has
gradually been erected. Again, no doctrine in historical
geology has had so vital an effect, so world-wide an
influence, as that cf the identificaticn of the individual
geological formations by their organic remains. And
even at the present day it is the biological or palonto-
logical section of historical geology which, at bottom, is
the more powerful. I can confidently assert (even from
my own experience, and mine is only a type of the
experience of others) that whenever the geological section
of historical geology—stratigraphy—and its biological
section—paleontology—are in conflict, it is the biological
side which is invariably the victor. The whole history of
the progress of geology is starred with names of biologists
and palzontologists who have enriched that science by
their ideas or their discoveries, from Moro to Cuvier, to
Hdward Forbes, Agassiz, Huxley, Wallace, and to the
great Darwin himself.
I have said that there is no need to apologise for the
existence of the science of geology, or to claim a place
for it among those sciences beneficial to humanity, to
biological men. I wish, however, I could say as much for
488 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
the side of the economist and the British public at large.
It is strange how so few of those who interest themselves
in the commercial progress of the British Islands and our
great Colonial Empire are aware how great a part is
played by matters purely geological, and by the minerals
and mineral wealth, which naturally falls to be dealt with
by practical geologists. And here, perhaps, I may quote
what I wrote upon the matter some years ago when
treating of some of the work done by geologists and by
geology in Britain. “It is a fact which no one dreams of
disputing, that the primal cause of the uninterrupted
progress of our country, almost from the days of the great
Elizabeth down to those of the greater Victoria, has been
the vast store of mineral wealth that Nature has placed
round the homes and at the very feet of our people. Talk
of the great landed nobles as we may, boast of the sturdy
yeomen of the land and the hardy sailors of the seas, yet
at the back of them all, at the back of all our national
progress and prestige, le the great coalfields and iron-
fields, which have founded and fed our great manufactur-
ing districts. These in their turn have furnished employ-
ment and subsistence to our teeming populations, have
brought wealth, leisure and influence to our middle classes,
and have afforded to the nation at large the means of
trade and inter-communication at home, of transport and
commerce on the seas and of colonisation and conquest
abroad.”
Let us consider the economic relations of geology in
Britain alone, and endeavour to realise, at any rate in
outline, the enormous value of the mineral products with
whose nature and distribution the geologists have to deal.
The monetary value of our mineral products at the pit
mouth alone, according to the latest published Blue Book
(1900) on the subject, amounted to more than 135 millions
GEOLOGY IN ECONOMICS AND EDUCATION. 489
sterling. Indeed one can hardly over-estimate the
importance and! variety of those British mineral produc-
tions, the places and characters of which are mapped out,
described and studied by our practical geologists. These
mineral productions include not only the coal, ironstone
and limestone deposits worked by the coal miner, the vein-
stones wrought by the ore miner, searching for tin, copper,
lead and the lke, but they embrace all that long array of
mineral material employed by the architect in almost
every kind of building construction, or by the engineer in
making and maintenance of roads, aqueducts, and
railways.
A few years ago coal was ignorantly sought in every
geological formation. But since the coalfields have been
mapped by geologists, and the maps and_ sections
published for the people, this waste has practically ceased
(at all events in those cases when the owners and
speculators have consulted competent geologists, or have
been themselves familiar with tthe results of geological
research). By means of a certain amount of geological
knowledge, and the ability to understand and to utilise
geological maps and publications, the landowner in a coal
district can now ascertain broadly the extent and value
of the coal or iron seams on his estate; the mining
engineer can fix on the best place for his new shafts, and
can estimate beforehand the amount and quality of his
needed engine plant. The borer for coal, iron or water,
if he has only a fair amount of geological knowledge, can
in most cases determine for himself beforehand the
thickness and nature of the strata which he will have to
pass through, and consequently the probable costs and
profits of his undertaking.
“Not only has the advance of geological science, and
that faith in its results which has gradually made its way
490 ‘TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
among a few practical and commercial men, prevented
waste inside the coalfields themselves, but it has
stimulated mining and commercial enterprise outside
them. It has already led to the successful working out
of profitable coal seams far outside the visible limits of
our actual coalfields, away under the red rocks and other
barren formations, where none but a geologist would ever
have dreamt of sinking for profitable minerals. And
more, it has demonstrated the probability—and in some
cases almost the certainty—that most of our present
visible coalfields are connected together underground by
a continuous chain of hidden coal seams, which are
all destined sooner or later to be worked with profit.”
Leaving altogether out of account the recent discovery
of coal in Kent and elsewhere, a discovery prompted solely
by the geologist and by geological inferences, we find that
all our existing coalfields are extending their borders deep
under the red rocks which surround them to even greater
and greater depths and over broader and broader stretches
of country. There can be no question that on the enlarge-
ment of our present coalfields, through the combined
discoveries of geologists and the advancement of mining
engineering, the future prosperity of Hngland mainly
depends. When all our coalfields have been discovered
and worked out, it has been well said “the main-spring
of our commercial enterprise will be gone.” How
important, therefore, it is for the well-being of our people
that the study and practice of geology shall be encouraged
and fostered by the men of enterprise and commerce who
deal with the mineral resources of the land.
Of course the value of a knowledge of geology,
geological mapping, and the like, to those who work in the
search of metalliferous ores of copper, tin and the like,
has been acknowledged from the first. Indeed, it was the
GEOLOGY IN ECONOMICS AND EDUCATION. 491
ancient ore miners and ore mining schools of Germany
and Britain which originally laid the foundations of
practical geology itself. But the advance of geological
science and mining engineering during the last fifty years
has opened out an enormous series of ore-bearing deposits,
unknown and unthought of by the ore miners of a century
ago. Such, for example, are all the bedded iron ores of
our Hnglish secondary deposits—those of the Lias and the
Oolite—which indeed at the present day afford two-thirds
of our total iron supply. Whole districts like those of
Cleveland, in Yorkshire, and Central Northamptonshire,
and towns like Middlesbrough, Wellingborough, and
Kettering, have rapidly sprung into great wealth and
importance in consequence. It was the stratigraphical
geologist who first made known the exact places of these
rich deposits in the stratified rocks, following them from
point to point, and putting them down on his maps, so
that the miner and the mineowner might know where to
seek them, and how to work them to the best advantage
and the greatest profit.
But the utility of a knowledge of geology is almost as
great to the architect and engineer as it is to the mining
man. ‘The discoveries of British geologists have placed it
beyond question that almost every kind of stone used in
building construction has its own place in the scale of
British formations, and its fixed range across country can
be determined by the working geologist. ‘The freestones
of Portland, Bath, the famous building stone of Barnack,
York, Nottingham, the millstone grits, the carboniferous
limestone beds so largely employed in the North of
Kngland, have had their geological places determined years
ago, and it is part of the training of a geological student
and a practical geologist to know where they are and how to
seek for them whenever he is consulted upon the subject.
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And it is precisely the same with all the great varieties
of clays, of which, in the form of bricks, most of our great
towns are built. They have all their known and their
ascertainable positions, and it is the duty of the geologist
to ascertain and study and describe the various rocks and
rock-sheets themselves in detail, and it is his business to
be familiar with those not only available for building
purposes, but also those suitable for road making and the
hke. Over most of our English geological formations the
local road metals are soft and indifferent, but in certain
districts, such as Charnwood Forest, Shropshire, Cornwall
and Devon, rocks excellent for road making purposes
occur, all familiar to the working geologist. Every single
district in Britain is bound down irrevocably by the
geological conditions of that district as respects its fuels,
its building stones, its road metals, its cements and the
like, conditions which render these materials relatively
cheap and relatively costly, as the case may be. But each
district can repair its own deficiencies from elsewhere, or
can enrich itself by parting with its surplus, by taking
advantage of the geological conditions of other areas. The
information obtained and codified by the geologist,
properly interpreted, enables the landowner and the
business man to ascertain in what other districts the rock
he requires is obtainable, where there is likely to be
monopoly or a superabundance, and where there is likely
to be the greatest demand; and it is to geology and the
geologist that the District Councils, contractors and
engineers must apply for information as to the nearest
district or locality whence they can obtain the minerals
they require in the needful abundance and of the necessary
quality.
In matters of water supply, again, the knowledge and
the special training of the practical geologist are of the
GEOLOGY IN ECONOMICS AND EDUCATION. 498
very first importance. The relative thicknesses or special
natures of the local geological formations round a village,
town or city make all the difference between success and
failure in a water supply both as regards quality and
quantity. But it is almost like carrying coals to New-
castle to make an assertion like this in Liverpool. All
the city is well aware that its original water supply owed
its first success, as well as its subsequent failure, if | may
eall it so, purely to geological considerations, namely, to
the thickness, the characters and dislocations of geological
formations in and around the city itself; and all the water-
bearing formations of the British Islands, hke those of
Liverpool, have each their fixed geological position, which
the trained geologist knows, or should be able to ascertain
for himself or for his employers. Or further, if we have
to deal with the great surface water supplies brought
from a distance, like that of Vyrnwy brought into your
own city, Thirlmere for Manchester, or Rhuyader for
Birmingham, we find that the water engineer is dependent
upon the facts furnished to him by geology and the
geologist. The catchment basins of the reservoirs must
be floored by an impervious geological formation, his great
retaining dams must lie on solid geological ground and
guaranteed safe by the practical geologist. It is to the
geologist that he applies for information for the necessary
materials of which his dam is to be constructed—puddle,
clay and building stone. rom the geologist and the
geological maps and sections he should obtain the desired
information respecting the extent, the character and the
range of all the rocky material his aqueduct must be cut
through—whether in open work or in iunnel—along its
entire track from his storage reservoirs to his district of
supply. When we realise that the original cost of such
great overground waterwork undertakings to companies or
494 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
to ratepayers is enormous, that on the stability of the
works themselves and their immunity from all chances of
accident depend the lives of thousands, and upon their
proper construction from end to end depend the daily
health and comfort of millions of people, the need of
accurate geological information and its efficient utilisation
in waterwork engineering is beyond all question.
But geology not only has its uses for the miners, the
architects, the County Councils and the engineers, but is
altogether bound up with the art of agriculture—the
oldest and most widespread profession, if I may call it so,
in the world. All these soils cultivated by the agricul-
turalist are the broken up débris of the geological forma-
tions, and they vary from place to place and from district
to district in fertility and barrenness in proportion accord-
ing as the geological formations change, or their materials
have been transported by geological agents in the past.
Aud with agriculture and the comparative richness of our
soils is bound up the fact that each geological formation
plays its individual part in the comparative fertility. or
non-fertility of every broad district of country, considered
as a whole.
I have no doubt that the dwellers in Lancashire and
Cheshire could furnish me with hosts of examples, but I
will take two examples selected from the country best
known to me, namely, the English Midlands: The long
stretch of country underlain by the Triassic pebble-bed
formation of the Midlands, poor in sub-soil and weather-
ing to gravel, is even at the present day a region of
heath land and forest land; dry, barren of population,
and of but little surface value. But side by side with it
upon its outer border runs for hundreds of miles a
narrower band of country floored by the formation known
as the waterstones. This waterstone band, rich in
GEOLOGY IN ECONOMICS AND EDUCATION. 495
underground waters and weathering easily into open sub-
soil, has been settled upon for untold generations. The
earliest dwellers in the land fixed upon this waterstone
band for the sites of their homes, the barons of feudal
times for their castles, and their retainers for their
villages, the manufacturers and merchants of later times
for their places of trade and residence, and upon it to-day
are situated most of the chief towns of the Midlands and
their fashionable suburbs. Its rich soil has been culti-
vated for centuries, and year by year more and more of
its extent becomes enclosed for parks, gardens and
private estates.
And so we might go on to shew how the health of our
people individually, and indeed many of the most
dominant factors in the hygiene of our towns and villages,
such as the dampness or dryness of the soil, sites
for town and village sewage disposal, water contamination
and the lke, depend upon geological fact, and how
necessary in most cases is the careful application to these
of sound geological knowledge and practice. But I have
said enough, and perhaps more than enough, to shew how
the practical parts of geological science are bound up
with the wealth, the health and comfort of the people at
large, and how all of us are more or less affected, from
the economic point of view at any rate, by geological
facts and geological knowledge. The more that know-
ledge is added to by the geologist, and the more accurate
and the more widespread it becomes; and further, the
quicker and the cheaper that knowledge is applied and
utilised by those concerned, the better will it be for the
health, the wealth, the comfort, and the progress of the
entire community.
But this purely economic side of geology is only one of
the many aspects and departments of the science. In the
‘496 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
very earliest stages of its history it was more or less bound
up with mineralogy, which stands related to chemistry
as paleontology to biology, and with this inorganic
chemistry it has developed side by side. But it has added
to mineralogy the great sub-science known as petrology or
petrography, which deals with all the mineral constituents
of the earth-crust and with their groupings and inter-
relationships, actual or theoretical, present and past.
Indeed, within the last ten years or so, to not a few who
call themselves geologists, petrography is the be-all and
end-all of the science itself. Fortified by the advantages
afforded by the invention of the microscope and its great
improvement in recent years, as well as the advance in
chemistry and optics, some of us are tempted to pay too
much attention to the study of rocks and rock slides, to
the neglect of other branches of the science. There is
no hkelihood that this side of geology can be ignored. It
has opened out to us the grandest views of the origin and
evolution of rocks in general. The day is fast approach-
ing when, taught by Nature’s methods, the student of this
branch of geology may learn to imitate and manufacture
in their laboratories even the natural jewels which are
the most valuable of all the mineral products known to
mankind.
The second stage in the history of our science after its
mineralogical childhood was its glorious youth, when in
company with its biological sister it entered upon the
study of fossils and of the geological formations. And
with what a wealth of natural facts and natural phenomena
has this branch of our science enriched human knowledge
and human philosophy. It has unravelled the structure
of almost all of the rock formations of the British Islands
and made them the accepted model for the whole scientific
world. It has proved that in these formations we have
GEOLOGY IN ECONOMICS AND EDUCATION. 497
the past history of our planet from the dawn of existence
down to the present day, written in characters that every
trained geologist can interpret and every conscientious
student of nature must accept as true. It has destroyed
the old and cramping notions that for man’s behoof the
earth and its living tenants have been created and that
without him it would have neither use nor meaning. It
has replaced this vain-glorious conception, by the wider
knowledge and more ennobling view of the present day,
that this earth of ours reaches back through an immensity
of time transcending all human conception and that it
has been for an infinitude of generations the home of
animated beings all bound together in one great family,
one great chain of progress, by a mutual kinship and a
common experience of birth, joy and suffering, life and
death.
At the present day no man can be called a well-educated
man who does not recognise how much this historical
branch of our science has done to increase our knowledge
of nature and to broaden the outlook of human philo-
sophy. And so vital do I take this knowledge to be to
the biologist, the political man, the student of mankind,
the teacher, the theologian, the practical man, and even
the ordinary man of the world, that I would urge upon
each and all of them the necessity of making themselves
acquainted with at least the principles, the methods, and
the results of geological science.
The third stage in the development of our science of
geology might be described as its geographical stage.
The initiation of this stage we owe to the great Hutton
and his apologist Playfair, who were the first to discover
or to suggest that all the geological phenomena of the
great rock formations could be interpreted in the light of
the physical geology of the present. But this branch
498 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
remained under a cloud of misapprehension and unbelief
for nearly a century, and it was reserved for the genius
of Charles Lyell, hardly more than fifty years ago, to lift
that veil and compel the thinking members of mankind
to recognise that geology is in effect the sum of the
countless geographies of the past, and that the geography
of our own time is merely the geology of the present.
But it is only of very late years that the geographers
themselves have been willing to admit this fact and to
employ geological science in their own interpretation of
geographical phenomena. Nowadays, we are threatened,
however, with a flood of geographical literature coming
from their direction. Now, simply because its inhabitants
speak a kind of geographical language, Lesley, Gilbert,
Suess, Penck, and Davis have shewn hew in the matter
of mountain chains, plains, rivers and the coasts of the
present day we see in each and all a link in the unbroken
chain of geological cause and effect. . What was, a few
years ago, to the geographer a geographical phenomena,
to be accepted merely as a topographical fact and nothing
else, becomes endowed with interest and with life, when
it is shewn in this way to be a passing phase in the
unbroken course of geographical evolution. But I am
still of the opinion that much of what is written is beyond
the grasp of the average geographer. For the proper
study and appreciation of this so-called branch of geo-
graphical science, a knowledge of the principles and the
practice of stratigraphical geology is absolutely
indispensable.
At the present day the science of geology is entering
upon its fourth and highest stage, in which the science
of physics, or natural philosophy, is destined to play the
most important part. Now that the general distribution
and characters of the great geological formations have
GEOLOGY IN ECONOMICS AND EDUCATION. 499
been sketched out nearly all over the world, and now that
it has come to be recognised that they owe their present
positions and their relationships to the actual outward
form of the earth’s surface, to changes in position brought
about by the deformation of the earth’s crust and its
various parts, we are beginning to codify the effects of that
deformation and to set about the task of discovering the
laws which rule in the process. We have as yet, it is true,
done little in this department, but the great works of
Suess, Heim, Bertrand and many others, all tend to show
that the grander deformational effects have been brought
about by the same causes, and are certain eventually to
fall into line with, and perhaps become compressed under,
a common nomenclature with the corresponding results
worked out by the physicist in his laboratory at home.
It is very difficult to say at what period of life a pupil
or a student should properly commence the study of
geology. It is the one science among the natural sciences
the principles and illustrations of which may be largely
taught in the common language of the pupil. By means
of such language alone the teacher or indeed the pupil
for himself may build up the ideas of precise phenomena
in more or less scientific terms. To the average school-
boy it is an exhilarating and mind-expanding subject
when properly taught. It is a subject which unlike
chemistry, physics or even zoology, demands no great
expense in the matter of laboratory apparatus. A col-
lection of minerals, hammers, a clinometer or compass,
a map and a bag for carrying his lunch and his fossils,
and you have the complete outfit for every member of a
school class setting out on its first geological excursion.
The collection of his first rocks, his first fossils by a school-
boy, who knows just enough geology to be aware what
they mean or what they imply, is a pleasure never to be
500 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCTETY.
forgotten, and every fresh out-door discovery gives him a.
thirst for more knowledge of the subject and more out-
door delights. And, if no more results from the excur-
sion than this, yet as Sydney Smith puts it: “If you
make children happy now, you will make them happy
twenty years hence by the memory of it.” But with a
good geological teacher infinitely more may result. Even
as a science of observation alone, geology trains the boy
to observe accurately, to record correctly, to compare and
to systematise, and at every fresh step there is a fresh
inference to be drawn or a new fact to be explained and
accounted for. Not only so, but the science of geology
branches out in all directions and the boy picks up almost
insensibly in the course of his work some of the more
important results obtained in other sciences, in chemistry,
in physics, in biology, in physical geography, in meteoro-
logy, and his mind becomes stored with facts of value
for him in his after life. His reasoning powers become
strengthened, broadened and stimulated by the host of
inferences and deductions, inductions and verifications he
has made during his geological progress. He learns the
use of maps and sections, his eve becomes trained to note
the form of the country, the distribution of its rock form-
ations and all their relations to nature and to man.
“When we recollect how many of the hundreds and
thousands of the pupils in our public schools are destined
to become landowners, agents, architects, engineers,
officers, and the like, and it may be pioneers and dwellers
in the great colonies and dependencies of the Empire, it
appears almost a crime that at least the outlines of
geological science and physical geography are not taught
in every one of our public schools.”
That geology should be taught in every University
College goes without saying. I think I have said more
GEOLOGY IN ECONOMICS AND EDUCATION. 501
than enough already to show that no civil engineering
course can possibly be complete without it; it is indis-
pensable to the student of mining, it is almost as necessary
for the metallurgist, and more than good for the biologist
himself. For agriculturalists and County Councillors, for
architects, and for doctors desirous of qualifying in the
matter of hygiene and public health, if it isnot an absolute
necessity—at all events it is most highly desirable. To
the traveller, whether in Britain or abroad, a knowledge
of the science adds immensely to the interest and value of
what he sees. To the theologian, the student of history,
of humanity and of human philosophy, it gives that clear
conception of man’s place in Nature which it should be
their duty to ascertain as much as it is his pride to teach ;
and to the so-called educated man at large it presents that
broad outlook over the whole realm of Nature which is the
natural supplement and correction of ‘his one-sided culture.
To the landscape painter and the lover of scenery for
its own sake there is hardly any need to point out the
interest and value of a knowledge of geology. Tor the
words of Hugh Miller himself—no mean judge of geology
or landscape—“ Geology may be properly regarded as the
science of landscape. It is to the landscape painter what
anatomy is to the historic one, or to the sculptor. In the
singularly rich and variously compounded prospects of
our country there is scarce a single trait that cannot be
resolved into some geological peculiarity in the country’s
' framework, and which does not bear witness to some
striking event in its physical history. Its landscapes are
tablets roughened and engraved, like the tablets of
Nineveh with the records of the past.”
But it has been said, and said often, that the study of
geology is destructive of man’s feeling for beauty and
mystery, and fatal to the exercise of the imagination and
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502 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
of the poetic faculty. No assertion could be farther from
the truth. There is no science which demands so
frequently the highest efforts of the imagination, nor one
which is more crowded with those mysterious problems
of Nature and so beloved of the poet. The reply given
half a century ago to a poet who complained that “the
rocks were stratified by geologists as cloths are measured
by the mercers, and are in consequence no longer redolent
of that emotion of the sublime which was wont to breathe
forth of old from broken crags and giddy precipices ”
remains to-day as true as when it was spoken.—‘ The poets
need be in no degree jealous of geologists. The stony
science, with buried creation for its facts and its domains
and half an eternity charged with its annals, possesses its
realms of dim and shadowy fields, in which troops of
fancies already walk like disembodied ghosts on the old
fields of Elysium, and which bid fair to be quite dark and
uncertain enough for all purposes of poetry for ages to come.”
Speaking as an old Geological Professor and teacher, I
must acknowledge that I hold Liverpool to be an excellent
centre for a School of Geology. You have in your College
itself already a Scheol of Engineering and a School of
Biology. You have in your great city a host of people
who are, or who cught to be, interested in knowing all
that there is to be known of the natural products of Britain
and of foreign countries for the purposes of commerce and
of trade, and who ought to be desirous of securing for
themselves and their sons that special knowledge which
shall enable them to know where to seek for and how to
secure those productions wherever they are to be obtained.
You must, in addition, have a host of persons of leisure,
of travellers to whom the study of geology would be a
relief and a means of adding to their enjoyment and to
their culture.
GEOLOGY IN ECONOMICS AND EDUCATION. 503
You have within easy reach of Liverpool City some of
the finest exhibitions of Post-Tertiary geological deposits
in the British Islands. The glacial deposits of Lancashire
and Cheshire, as Mr. Mellard Reade and Mr. Lomas have
shown, are crowded with geological problems yet awaiting
solution. Your Triassic rocks, in spite of all the excellent
work my old friend, Mr. Morton, did amongst them, are
rich in problems equally mysterious and fascinating. The
wonderful series of dislocations which have brought about
and fixed the site of the great Dee-Mersey depression,
which constitutes the very foundation of the wealth and
prosperity of Liverpool itself, are still unsystematised and
still unexplained. You are within easy reach of the coal-
fields of Lancashire and Flint, and it is yours to discover
the hidden places of the Cheshire coalfields that probably
he to-day deeply buried below the barren red rocks
-between, awaiting the progress of geological research to
render them available for the use of future generations.
The lovely Paleozoic districts of North Wales, the Isle of
Man and the Lake District itself are within the limits
almost of a day’s excursion. With all such advantages of
position, and with all the daily growing appreciation of
the economic and the intellectual benefits of the science,
surely it is not too much to hope that a vigorous and
successful career is before your Geological School.
But after all, success or failure does not so much depend
upon the utility of a science, either economically or
intellectually, as upon the enthusiasm of its teachers and
its votaries. ‘hat enthusiasm is, indeed, whether confined
to the individual or communicable to others, its own great
and excellent reward. Nor even should we complain if
among our geological students we have many who decline
to submit to the yoke of examination, and are consequently
unknown to the list of those bearing our University
504 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY.
degrees, but are content to be numbered among that
heterogeneous crowd of geologists popularly known as
amateurs. ‘'hey and their teachers and their companions
may comfort themselves in the fact that all the most
famous geologists of the past have been in their day
amateurs in the science—Hutton, Murchison, Lyell,
Sedgwick, Ramsay, De la Beche, and in modern times
Heim and the great Suess. This is surely a great and a
goodly company. ven if we ourselves never rise higher
than the amateur stage in one or more of the many
branches of the science, and get merely an occasional
geological outing in the country, and collect only now
and again a new fossil or make an original observation—
what more glorious and exhilarating than a summer
geological excursion in the field! From the sunny morn
to the dewy eve, the entire land we traverse is all our own.
There is the charm of freedom, there is the keen joy of
the chase. The hunt for discovery is as exciting as the
hunt for game, and moreover, it is all unstained by the
horror of bringing death to a helpless creature. Rather,
on the other hand, have we often the delight of restoring
to life and light some grand geological phenomenon
hitherto dead to science for want of its true interpreta-
tion; or we have the pleasure of discovering some fossil
relic of the extinct creatures of the lost geological past,
and in the words of the great historian—‘ He who ealls
what has vanished back again into being, enjoys a bliss
like that of creating.”
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