4

tlh
thet

ie .

LN

ii dsetaane
vi) tlaien a)
watas §s°

hei cera

te
Ly

nate >
i J Hae oe: he ity nied
4: py bad ag 44 oe
eat Spades Gee ta elas 7
my ahs As ca tre
i iy tt
a

hai

one
ide ve e
5 a hh a fi Hite
elie ithe ies

u}
‘be riigh

ei

rt

ie. ‘ i
eueets ae
ba he

arr
Aaeti jy) ae:
re Th,
4
+4 ols M . eee
creat a ait Les j ‘ yen Haas gn
beaeaseng sn 4 9 4 fH earar stg 444 ; yeas ts
Ce ara 4 Ghd ire Had : } z
Ai4e S94 ; r hie
Dt ed rt
Hoes hd hte ¥ i
HF host snd te Nah phe
.) she het 4)
te bi

ieiot
ttn ay ri *y
e die ai a4
yeas at pote, io
gs a eal
cue RAMS 4
sh with cn
lin i nyu A
ees se
q ° ' ant
pe ii rbot duet ie ite on oe at
hid 6243 Cr icant he vate i eo ili
we this Be ‘ sesatenssrateratn Wee La i oe
hod te pine Perret ter erate te Siti Hester i
Pu epee we nnd watt MPM Hirer sane} Hi roa
4 Luh Het ne rit eins st ahh
Cake Basa ce ett

hiaahe

Hans statist ase Fe ae
is F i My

silt

Bos ee Das

57m
i Livia Peis
“i * 4. bs ay sy: .

Hh Pe beatae | i 4
HAD phe

“th
neat ts : i
- ny ‘ a f inv pat et
eae aa
: n r ‘ ipalifitr
mantras oT 6 ih} red
dt Rcty sdaaeke Mite?)
Hagen ida hs Ree SSPE
aia pide Ha f
da pete
wri Ot

th
i
a ae

Hie

ive

New Series VII.

‘DOVE “MARINE. LABORATORY,

Cullercoats, Northumberland.

‘REPORT
ee ‘For the ‘year ending pane goth, ists

Stas BY ALEXANDER MEEK,

te “Paorzsson OF Zoouoey, “AmustRoe Couunen, IN" THE UNIVERSITY oF DuRHAM,

AND
ae ‘Drrecror oF THE Dove MARINE eased

Published by the Marine Laboratory Commitee of Armstrong College
“on behalf of the Northwmberland Sea Fisherics Conunittee
: = and. other contributing anthorities.

NEW SERIES VII.

DOVE MARINE LABORATORY, _

CULLERCOATS, NORTHUMBERLAND.

REPORT

For the year ending June 30th, 1918.

KpITeD BY ALEXANDER MEEK,

Proressor oF ZooLtocy, ARMSTRONG COLLEGE, IN THE UNIVERSITY ofr Duruam,
AND

DirEcCTOR OF THE Dove Marine LABORATORY.

Published by the Marine Laboratory Committee of Armstrong College
on behalf of the Northumberland Sea Fisheries Comunittce

and other contributing authorities.

Price . = Five Shillings.

TRewcastlecon=Tyne :

Cait & Sons, PRINTERS, 29 anD 31, QUAYSIDE.

1918,

Marine Laboratory Committee.

Principal W. H. HADOW.
Alderman J. CROMIE.
Alderman R. MASON, M.P

Councillor H. GREGG.

Professor A. MEEK.

W. S. VAUGHAN.

i J. 8. REA.

CHARLES WILLIAMS.

F, H. PRUEN, M.A., Secretary.

Director - = -

Naturalist = -

Librarian = =

Staff.

= - Professor A. MEEK.
- - BENJAMIN STORROW.*

- - DOROTHY STONE.

* Serving with H.M. Forces.

CON RENTS:

SUMMARY AND GENERAL REPORT

HERRING INVESTIGATION, 1917 (2 Figures)...

By A. Meex and Dorotuy STone.

POLLUTION OF THE TYNE

By A. MEEK.

PROPOSED MUSSEL BED AT HOLY ISLAND

By A. MEER.

ON THE CRUSTACEA (10 Figures)

By A. Mrex.

PLANKTON OF THE SUPPLY TANKS OF THE DOVE MARINE
LABORATORY ..

By Otea M. Joncensen.

OCCURRENCE OF AMPHIDINIUM OPERCULATUM AT CULLERCOATS

By Ouca M. JornGENSEN.

NOTE ON THE LARVAE OF GRANTIA COMPRESSA (1 Figure)

By Ouca M. JoRGENSEN.

NOTES ON THE DEVELOPMENT OF CARCINUS MAENAS ...
By Ouea M. JorGENsEN.
FAUNISTIC NOTES (2 Figures)—
NEMATOSCELIS MEGALOPS ...

CALIGUS CURTUS ee a8 os ea

PAGE,

16

13

46

60

62

65

66

SEE SS

Dove Marine Laboratory, Cullercoats.

SUMMARY AND GENERAL REPORT.

During the year ending 30th June, 1918, in addition to
general work connected with the coastal fisheries, a series of
investigations were undertaken and are now reported upon.

Samples of herring were obtained from Berwick, Sea Houses
and North Shields, altogether amounting to a total of 3,200
herring, and from the chart indicating the localities of capture
it will be seen that the district was fairly completely covered.
The samples again proved to be very similar in size and in age
composition, thus evidencing that the Northumberland herring
belong to one school. As in the previous season herrings with
four winter rings were predominant; an interesting and note-
worthy feature. Up to 1915 our investigations showed that the
herring consisted for the most part of four year herring that is
with three winter rings; in 1916 and 1917 the school has
presented a majority of five year old herring (with four winter
rings). It is fortunate that we have persevered with the herring
investigation at this time for it may turn out that the advance
in age composition is due to the restricted fishing. Reasons are
given for the conclusion that spawning took place in the northern
part of the district at the end of August and the beginning of
September.

In 1918, as in 1917, the dry weather in the spring brought
the Tyne at Newcastle into a serious state of pollution. Many
kelts were poisoned, and in May the smolts, after hesitating
above the tidal region, were tempted by a slight amount of rain
to descend. Hundreds were killed opposite and below the gas
works. It is not suggested that the gas works alone are respon-
sible, nor that at present any particular effluent can be blamed.
A collective plan of reducing the pollution will have to be
adopted, but it cannot be urged that the present is a convenient
time for undertaking it. Still, even now, the managers of works
on the Tyne might be asked (and they have been asked by the

6

Tyne Salmon Conservancy) to do all they can to prevent poisonous
effluents being poured into the river, and to see that poisonous
products are not deposited on the banks.

An important step has been taken as to the formation of the
mussel beds at Holy Island. Arrangements have been made for
obtaining a lease of the area, and it is hoped that a beginning
will be made in transplantation this season.

A paper on the Crustacea is meant to draw attention to the
confusion which exists regarding larval nomenclature, and
especially to bring together the knowledge we possess as to the
growth and the age of various species, based mainly on the series
obtained by G. Brook and Mr. Waddington. The statement
shows that the Decapod Crustacea only reach maturity after
about four to five years from hatching, and that the crab and
lobster, for example, may reach an age which cannot be said to
be less than 20 years.

Miss Olga M. Jorgensen, M.Sc., contributes a series of papers
on the work she has been engaged in during the year. The
first gives the results of an examination of the water of the tanks
of the Cullercoats Laboratory, with a view to indicating the
nature and the quantity of the micro-plankton of the water
supply, and incidentally the changes in the micro-plankton of
Cullercoats Bay. It is shown that the tanks and the sea
undergo the spring and autumn increases so generally observed
in the North Atlantic region, but it is plain that the maxima
are intensified by the accumulation of plankton in the tanks
between the periods of pumping. The results, therefore, do not
give a true picture of the sea plankton, but they give an in-
teresting and important indication of the monthly variation of
the micro-plankton of the tanks and the lists of species will be
found to be of great value.

Amphidinium operculatnm, which was recorded for the first
time in 1913 and has appeared irregularly since, was found in
1917 and 1918 from November to May. It has thus, so to speak,
become established at Cullercoats as Herdman has found it to
have been at Port Erin.

7

Miss Jorgensen adds a note of importance to her account of
the development of the common calcareous sponge Grantia com-
pressa. The larva appears to be free for at least 24 hours, and
is thus liable, like the larvae of so many other marine forms, to
denatation. She also gives an account of the larval stages of
the common shore crab; and her drawings.of the larvae of this
and other species will be found in the paper on Crustacea referred
to above.

Interesting records of the Euphausian, Nematoscelis mega-
lops and of the parasitic copepod Caligus curtus with its parasites
are given under Faunistic Notes.

A. MEEK.
25TH JULY, 1918.

HERRING INVESTIGATIONS, 1917.

By A. MEEK AND DOROTHY STONE.

We were able during last season to examine thirteen samples
from the Northumberland district, the total number of herring
being 3,200. We have pleasure again in conveying our grateful
thanks to all who were good enough to help us in the work ; we
would like particularly to thank Mr. Richard Dawson, of North
Sunderland and North Shields, and the Messrs. Holmes, of Berwick.

The nature and origin of the samples are given in Table I.,
and the localities of capture are indicated in Chart |. The North
Shields samples were examined at North Shields fish quay, the
Berwick samples in Messrs. Holmes’ curing house at Berwick. The
sample from Seahouses was sent to the Laboratory.

TABLE I
Sample. No. in | Date. Locality.
Sample. |

|i = No See “ele a
1 (North Shields) ... 250 5th July ...| 20 miles N.E. by N. of Tyne:
2 A a 250 20th July ...| 24 miies N.E. by N. of Tyne:
33 5 alts 250 29th August ...| 20 miles E. by 8. of Tyne.
4 “ sae 250 12th September 18 miles E. of Tyne.
5 5 wa 250 15th Septemher 20 miles E. of Tyne.
A1 (Berwick) ...| 250 | 7th July ...| 15 miles N.E. of Berwick. ;
A2 i Bee 250 27th July ...| 15 miles S.E. of Berwick.
A3 3 as 250 9th August .... 15 miles E. of Berwick.
A4 a : 250 10th August ...} 15 miles E. of Berwick.
Ad ne ee AY 5th September 20 miles E.S.E. of Berwick.
A6 a Moc 250 | 6th September 20 miles E. by S. southerly of Berwick.
A7 ap o 250 | 7th September 23 miles E.S.E. of Berwick.
Bi (Seahouses) ... 200 Sth September 15 miles E. of Seahouses.

Our purpose mainly is to put on record the measurements
and the results of the examination of the scales. The details
with reference to size and the number of winter rings are given

Arbroat

Dundee
SF Andee
“Anstruthe
icMess
Kirkcaldy
Kinghor
Gmagemoutly
Lei
ugsel burglv

Balt RS
May
Al
e
Dundir
Cotinenene RE he
BA
Burnmost 6
eA
Berwéc! q
ef
Goswich B *
wweroe 2 A2 a5 Bh
Psd Z
Bate mt
"Beadnell
Dunstonborouah £7, }
Boulmer 3 °2
mauthB)
Alama hi Ne “1
DrusiageB
Croswely
i
ec
“a
sespeh Ft
Seriarys
Cullercoass
Tynemout
‘SonterP*
Sunderland,.
Scahamr
Hartlepool +
Cnart 1.

The approximate positions from which the samples of herrings were obtained.

>

on

i

ei

i .July 5
40 \
\ Al. July 7 "

/ 2.July 20

A2.July 27

Ao. Aug.9° —
A4. Aug.10-----

5. Aug. 29,

Ad. Sep.5 —

A6. Sep. 6 —

ATee SOD. if =

40

20 5.Sep.15.

ie 45 6 § ~y iad 20 81 of BS BE BS 26 27 Bo 29 50 Sl am
Cuart 2.

The age in winter rings (on the left) and the size in em. (on the right) of the samples
arranged in chronological order.

am 7™

= 4“ — a

~

i ML ees = = - - - ae ~_— «© e -

a ee _ ~ % . C
es bt= ep 9 : & cma) A ve ait haw its 9 hee ch
= Sao. ans ao {c. eee ee pee 8 . -— Se Sn RU Pans + shag ORT E

~

- 7s 7
were ong 5. fete - = 4 --

in Table II. in the form in which they have been presented in
previous reports. The results are presented graphically in Chart
2, which will be found to be interesting when compared with
the chart published in the preceding report and the figures for
past years. This year, as last year, the herrings with four winter
rings were found to be predominant. The change which we
recorded for 1916 in the age composition for the district is con-
tinued therefore in 1917. The shoals do not undergo a great
deal of change during the season, but it will be noted that herrings
with three winter rings were more common at the beginning of
the season, especially in the southern part of the district, that
these gave place to herrings with four winter rings which then
characterised the district generally, and that in August in the
northern part of the district herrings with five winter rings,
together with still older stages became prominent. The older
herring appear to have remained until early in September, after
which period the shoals were found to consist of the same class
of herring as were obtained in July. These general features will
be found to be very similar to those which resulted from the
investigation of the herring of 1916.

The change in the age-composition during the last two seasons
is an interesting and significant feature, which may be and pro
bably is associated with the present condition of the fishing.

a, %. <> }-

=

qm

. i

10

TABLE II.—SIZE AND AGE.

CENTIMETRES.

Te. 2
Sample | Tene 7 8
il 3 = | —
4 1 1

5 1 2

6 2|—

7 3 | —

7 3

2 3 == | =
4 1 | —

5 3 1

6 — 2

7 _ 1

4 4

3 3 —= | =
4 meere| ee

5 1|--

6 1} —

7 1 if

8 ed =

4 1

4 3 == | =
4 — —

5 ed —

6 “1}—

u i if

8 —_ 2

2 3

5 3 ey |
4 pose (apes

5 2\|—

6 — if

7 7)

8 ae |e

11

TABLE II.—SIZE AND AGE.

CENTIMETRES.
Sample. setae 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | Total
ings.

a 3 ene KOS. dae. laiiuly co uet | eaten eee 84
4 ea net oat ba ingen | reat gu ee Se ee aoe
5 eee) ee en TRE Tas lea ete Ha boat caer fp Sal ee oe 27
6 ee eae onlay ee 2) a | 2 2 Ue ieee es Ue areal eet ya 5
=| Bees) Sel Sheeley Ol 5S ay Myadeon ee el: eal al ogo
AQ 3 meet | gael 635 eT Gy| ie ee ee eel ee 76
4 S| ee ee eer sek laa) 5 a eee Re ea a
aa meee) 2.) 3) sr gn o | ot oan ea | pe 29
6 | 2s RE Smile ME aed Verso mee Maga en ee 12
7 ae ee el (|e ee el ele oat e eee 3
=|) 6 |/30'| 80) | 82 | 33 Gill o Wesel eenl Mons
AB 3 Maal AQ | A Lo ees eee [| 19
4 OO SG So. 4g oor aa | te pend ee eel ag
5 —|—|—j;—| 4] 8 |30!25}12] 2} 2}/—j 1 84
| 6 S| ig eee ET AE FR Waa ae Re GE
lanes ses |) | ee ey =] fA RE We 8g tl oa 6
| 9 | eae ee ee oe ae whe 1

| pei Sa) Ay a poes Bat] pas ee Neroeat Pen; |. iter fae SP pe 2
| —|—| 1] 2/18] 56. |84/51|20/10] 8| 1| 3] 249
A4 3 op || 8145, 29 | 18) 2) —)— |) =) —) 70
4 ea a gt hates endo. (i ae tical ee 97
See) | 1) 1) 4] 1 ja] 7 Wee eee (es rs Pe ee 49
fete Po i) ee a eae 2 21
7 >| Me 9 aa Di pee eee pa eal ie 9
8 ee Ne a ee ee | be 2
SS ea ee | 6S 24 | Sl con is.| “yell aaa | ong
AD ee | 2 Port 25- 5) ee ft 82
eer) | Ovo | 4 | age |osnl age f= |e} a) 2) ayo
5 | a es ios I) ra este dL Ls) 4) my eg ec bec Pai (Pais 44
6 a Rane rena a gs | 4 4| 2 ee aegis 12
| tes | Orlegoc eo lus | 55 | 21 1 — ar 1|}— | 250

12

TABLE II.—SIZE AND AGE.

CENTIMETRES.

TF >
Sample.| “iT | 19 | 20 | 21 | 22 | 28 | 24 | 25 | 26] 27 | 28] 29 | 30| 31 | Total.

3
4 eer elle (teal gies ne SS |S Se
5 SS ike) | eee) 30
6 Se ee ee ee 7
7 SS SS ase | 3

SS) = | — 1

3 2 | —|—
4 oe es eed ae 61 | 26 || 3 | eee
5 a) ee es le 9 gh ee) 39
6 SS SS SS 15) 4)/—|—}|—}]— 10
7 Se ee SS Se Se Ses a 7
g SS | | — | 2) ee 5
, ee 1

or
—
for)
c=
~J
ive)
w
Cpt
cs
—_
oo
for)
(or)
w
w
—
to
He
~I

Bi

|

|

|

|
a
wt
vo

|

|

|

|

|

ivy)
om w

CaAONa nh WNW
|
|
|
|
|
|
|

gs | 19 1 | 7 1 200

13

We have no distinct record of the spawning of the herring
last season, but notes were made as to the condition of the gonads
of the samples, together with general notes as to the herrings
landed at North Shields and Berwick. From these it is clear
that during the early part of the season in July and the early part
of August the herring were immature. In July the gonads were
in the state of 1-2 and 2-3 towards the end of the month, and in
August the Berwick samples indicated the presence also of herrings
with gonads of 3-4. Towards the end of August and the beginning
of September it was found that while the Shields samples remained
immature full herring were being landed at Berwick and Sea-
houses. These were succeeded by spent herring, which penetrated
throughout the whole district, being found not only in the northern
part of the district but amongst the herrings landed at Shields as
well. It is worth noting here also that on July 20th, when the
sample of that date was examined at North Shields, thcee boats
landed young herring measuring 16-19 cms., and it was stated
that they were obtained further north than the position recorded
for the sample.

The investigations of the Northumberland samples, which
have now been made without interruption for a good many years,
indicate that the herrings which annually visit the coast belong
to one school, which for some reason or other during the last
two years has advanced in age composition by one year. It is
evident, however, that we cannot arrive at a full comprehension
of the migrations of this interesting and important species until
measures are taken to insure a full and comprehensive investi-
gation on similar lines over a much wider area.

The facts given in Table IT. are summarised in Tables 111.
and IV.

14

TABLE III.—SIZE.

CENTIMETRES.
, |

Sample. 19 | 20 | 21 | 22 | 23 | o4 | 25 | 26 | 27 | 28 | 299 | 30 | 31

| | |
1 | Nos = | = | z-| ¢ | 87 | we) eo fo | 7.) oe
% — — — 3:6 | 14:8 | 42:4 | 27-6 7-6 2-8 1-2 7) == — —
2 Nos mS Le 7 | 47 |108 | 60 | 19 4 4 aio
of = | g4| = | 28} 1g6°] eee) O60) 7-61-%6¢] 16) =
3 Nos = = g 10 46 | 117 | 62 | 8 4 1 a= = =
o/, a 22: os |. 40] i¢-4 | 464 | 248] SE] 26! 04] = 24 =
4 oe o | 98 | Hs.) 77 | 68 (| ae 2 3 oe ee
o, ES |. = 0-8 | 13-2} 27-21 308 | 232] 44] o8| 1:2] O4] — | —
5 ct Se ee es 1-| i3-| 35 | 112-1 53 | 36 5 1} = pee ae
o, a Mh o-4| 52/1401 4481 21-2] 120] 20) of} =) =e
| |
Al Nos, 22) 2 SO SS 5 | 61 | 116 | 5S s| oS 9 | 23) ae ee
% = = —— 2-0 | 24-4 | 46-4 | 232; 32] O08] — = =_— =
A2 Nos. — |} -—) = g | 31 | 82 | 86 | 33 6 2 3),—)] =
o%, ee ee fe 28| 124] 328] 344/182] 24] o8| b2} — | —
A3 Nos SAE eee 1 @ 1 4 | 56 | S424 4. oe | a1 | ae 8 1 3
o, ye ee 0-4] O8| 52] 224; 336] 204] 84] 40] 32] O04] 12
A4 Nos a 1 gs | 98 | 84 | 68 | 24 8 a | 7. | =
o, a 0-4] 32] 112] 336] 272] 96] 32] 36] 52] 28) —
A5 Nos it 5 ee oS | el | Se. iP Sonal eet > ai £5)
% 0-4] 20] 2:4] 10:0] 20-4| 336} 220! 84! O04] — | — 0-4) —
AG Nos ~a a ae ee fe a eet pee a a 2 ee
% — | o4| 16] @8| 15-6] 336| 304+ 38] 16| — | O8| O8] —
A7 Nos = 2 5 16 47 93 | 57 | 3S 6 6 3 3 1
o% we |. = 2-0| 641] 188 | 37-2 | 22:8) 52| 24] 24] 12] 12] 0-4
Bl | Nos —|.— | 1) 4] 2 | zo | 88 | a7 | 8 | 10: } aoe
0, ee ae 0-5 | 20] 120] 35:0] 190! 85] 40] 95] 55| 35] O-5

15

TABLE 1V.—AGE:

WINTER RINGS,

127
52°1
110
44-0
128
51-2
146
58-4
153
61-4

126
52:1
122
50-4
114
45-7
97
39°1
112
44-8
124
50°90
125

50°6

66
33:0

36
14:7
24

9-6 |

58

48
19-2
50
20:0

27
11:2
29
1t-9
84

49
19-7
44
17:6
30
ao
39
15°8

29
14°5

33°7 |

16

POLLUTION OF THE TYNE.

BY A, MEEK.

In the last report I drew attention to the effects of the pollu-
tion of the Tyne in the early summer of 1917. I have now to add
to the record which I gave then a few particulars as to the destiue-
tion caused by the pollution this spring. Word was brought to
me from time to time of kelts being taken out of the river, and on
May 10th Mr. J. A. Williamson, Clerk to the Tyne Salmon Con-
servancy, wrote to me as follows :—

‘“* During the last few days there has been about 5 inches of
fresh water in the river Tyne, which, unfortunately, caused many
smolts to take to the tidal water. Hundreds have been poisoned,
and are being taken out of the river below the Team and Redheugh
Bridge by children ; the gulls have had a rare feed too.”

Mr. Williamson sent me six smolts taken on May 10th from
the river, and at the meeting of the Conservancy next day, |
obtained a further sample of thirteen, or nineteen in all. These
were found to consist of fourteen salmon smolts, measuring 13-3
to 18-2 cm., and five trout smolts, meauring 16-0 to 20-8 em., The
scales were examined, and it was found that eight of the salmon
had two winter areas, the rest having one winter area. The trout
consisted of two which had spent two winters in fresh water,
and three which had spent only one winter before migrating. The
small sample indicated that the trout smolts of the Tyne are about
25 per cent. of the salmon smolts, and this is just about the pro-
portion the fishermen catch of the older stages in the river and in
the neighbourhood of the river, that is to say, in the Conservancy’s
district. |

I hope on another occasion to have an opportunity of analys-
ing the statistics of the salmon and trout fisheries, for they appear
to show that the young stages of the trout especially are becoming
steadily less numerous, and that both salmon and trout are sadly
declining in numbers. In the meantime I must be content with

i:

recording the destruction of smolts particularly again this season,
and to direct attention to what I stated in the last report as to
taking steps to ameliorate a condition of things which is threaten-
ing to bring the Tyne to an end as a salmon river. I should like
to urge that managers of works on the banks of the Tyne and its
tributaries in the Newcastle area should endeavour to minimise
the discharge of deleterious effluents and the deposition on the
banks of poisonous products, such as gas lime, until the time arrives
when some combined action can be made to restore the river to
a cleaner condition.

It will be noted that the salmon and trout smolts exhibit
a significant difference as regards size. The difference is horne
out by detailed measurement and morphological detail.

18

PROPOSED MUSSEL BED AT HOLY ISLAND.

By A. MEEK.

I intimated in the last report that the Northumberland Sea
Fisheries Committee found it could not proceed with the forma-
tion of the mussel bed on the lines which were contemplated.
They formed, however, a Mussel Committee, which, in association
with the fishermen, has made much progress in the matter. We
now see our way to make a start with the work of transplantation
on a fairly large scale, without at the present time taking the
fishermen away from their useful employment. It is obvious that
under present conditions we cannot expect to start on the scale
which was originally intended, but we hope nevertheless to trans-
plant to the Scaup a fairly large quantity of mussels, and the
progress of these will be watched with interest by the Mussel
Committee as well as by the fishermen. I hope to be able to
report that the preliminary work has been satisfactorily accom-
plished, and that in the near future we shall be able to supply the
whole district with mussel ba‘t.

19

ON THE CRUSTACEA.

By ALEXANDER MEEK.

1.—LARVAL NOMENCLATURE a wos 19
2.— GROWTH ... fad ae ake ane 23

1—LARVAL NOMENCLATURE.

The nomenclature of the larvae of Crustacea has got into a
state of considerable confusion. At all events, no one appears
to be able to say definitely what is meant by the terms Protozoea
and Zoea. Even with reference to the Decapoda these names
are indifferently applied to very different larvae and stages ;
protozoee may have seven, eight or thirteen appendages, and
zoe seven, eight, twelve or thirteen pairs.

There is fortunately no trouble as to the nauplius. Whatever
its shape, it isa larva with the three anterior pairs of appendages ;
and we apply the convenient term metanauplius to the imme-
diately succeeding stages in which segmentation takes place,
and the next few pairs of limbs make their appearance. We
can refer therefore with precision to larvae which are hatched
at the nauplius or at the metanauplius stage and to the meta-
nauplius phases of the former.

At whatever stage the larva is liberated from the egg, whether
at the nauplius or at some later phase, a series of ecdyses are passed
through during which the remaining limbs are developed and
grow. ‘The limbs may all remain in a rudimentary condition until
the number has been completed, or they may advance into a
functional state in groups. My suggestion is that we can best
define the stage at hatching and the subsequent stages by refer-
ence to the appendages which have been fully developed. To
give point to my plea, I have prepared a chart (fig. 1) which
indicates the nature of the development with reference to the
appendages in the various groups. The nineteen appendages of

20

the Malacostraca are arranged in vertical columns, and their names
as applied to the Decapoda are also indicated. The horizontal
lines opposite the names of the groups indicate the stage at which
hatching takes place, and the successive ecdyses by the step-like
breaks in the line. All the appendages to the left of the steps
in each case have reached a functional conditicn, or, in other
words, the steps refer to the ecdyses during which the appendages
to the right are completing their development.

It is usually assumed that the development of the Penaeidea
exhibits best the typical condition, and it will be convenient to
describe it now as serving to define the stages. The eggs of the
pelagic Penaeus are loosely attached to the posterior pereiopods,
andare hatched in the course of a day or so. The larva is a
simple nauplius bearing three pairs of unsegmented limbs. An
ecdysis coliverts this into a metanauplius, in which the carapace
is indicated and rudiments of the succeeding four pairs of limbs.
These latter attain full development at the next ecdysis, and
the larva now becomes a protozoea. The next four ecdyses and
instars complete the segmentation of the thorax and abdomen,
and mark the appearance and growth of limbs 8-12, as well as
the uropods which appear precociously early in Penaeus as in
several other Malacostraca. The posterior pairs of thoracic
limbs have not much room for development, and in this group
the last or the two last may not appear, or in the case of the
penultimate pair may have only a temporary existence. This
is the stage which may be called the zoea. During the next three
ecdyses the pleopoda are completed, and the larva attains its

adult quota of limbs. This may be called the megalopa, and Ra,

gives place with further ecdyses to the adult form when the limbs —
do not undergo any further marked modification.

These stages will be sufficiently plain from the chart. It is
still convenient in the case of the Sergestidae to define the succes-
sive stages of the elaborately spinulated larvae by such names
as elaphocaris, acanthosoma and mastigopus, but it is not necessary
to consider them here.

The Brachyura (fig. 2) are liberated in the condition which
in the Penaeidea has been styled the protozcea, that is to say,
the limbs are present up to and including the second mavxilliped,
and the larva is called by the name protozvea by authors. At

A tt tet

5 Ad eae IS A AE Le ans ne cement :
ie ae 7 gee. ee
4 opp fmm — — ee = aon tt
a ae | ; Sees Cea ee ene ae a oma

| cael
= ea Sand 5 t rm a mi ne ene | | | |
nll) if
H “4 & i l (as ssnarsciaceceatnarnnic naan eae wenn wre } ONES RR RR nani ate aarer deus: wvwtheon! v7. NS A ce LE TS I |
[othe wren wre mem or = pa | j i \ i
asl | | | ie fae | :
1
oe 2 i {_ cia a eeeteraeemeed arenes Load cones [eres i Ps 2a KA Pe, OS Oe Oe
oe oe
C J e ee os ae See | 2. Sa aero | | ee see | Ae, ee, ef k — s as \. x Saree eee
oS nee arene ned —— 7 panei nee ae ene
ce [| || S| Ee a
ax} f a ‘ eile a a ee —- oe = Sa i as et : Cl Lape ESL aan eee ee
orc] ‘ 5 é
€ tol | | = -
t4 € i | hd '
i | oc
| Kad

PHYLLOS

PROTIZOEA

t
a

er ins fs LN
\ ‘
H }
' t

See
BC

la
poet
oe a oes
| |
{ |
|

‘4
5
8

2 es eee L. aie PLease ee ee ee | eee as | eerie or eae
set “= ar Es AO, ae
Beets tol | lh LL
Cote ja, | | Te ee ee ae |
e a gl ae
!
>

wd
=<¢ ud
ee w
Fes
ji Za
na Mw GQ
ie
is

tae che
z
z ff
- wh

ORS a
ART ANTI MB Lt

Some 42 Fig

Seme HYPERIDE ——-
APSEUDE3.__ i
80 gia
CYPRIS)
CYTHERE,_.

EUPHAUSIACEA
MYSIDACE,A _ _
ISOPODA ...
KOONUNGA...... ...!
PARANEBALIA_.
PHYLLOPODA

STOMATOPODA_.
CUMACEA

PENAEIDEA ..
CARIDEA.
LORICATA.....
HOMARI DAE...
ASTAC! DAE......

BRACHYURA ......
F.
AHOMURA -. ..

AMPBIFODA .
BATHYWELLA. _...
NEBALIA..._.
CYCLESTHERIA
CLADOTERA.__.... dl
OSTRACO DA
CIRRIPEDIA......,
COPEPODA.......

FIGURE l.

FIGURE 2.

Carcinus maenas, the later larval stages (in the middle), after Williamson ;
the megalopa and young stage, after Brook.

=
7 < ~~
= - _
=
2 : ; :
e ; oe
= 7 a an —
: coe A =, ‘.
2 : : 7
5 7 a $ stk :
i . p == a
a te —s 7 — —
Ps 7 ac FS 7
aS .
ae = : :
as “= -
a ee :
: -
i
, ‘
a _ .
: ; 7 =.
“a =
>=. a 7 ;
25 7 =
. -
. i- '
V : = *
-
: ; 3
3 = 4 ;
7 : a
i =
2 a
8 |
= =
: 3
cs .
—_
| ¥ -
*)
; = -
ose ap
tie a
} . spate eit oe) Saat ic [>
a : aie fe :
: Fi aoe Ve = he: anaes al ae)
a) bd ee Cetera: DR DF Ne
. =" 7
| 7 :

0 ¥

FieurE 3.

Crangon vulgaris, after Williamson.

FIGURE 4.

Homarus valgaris, the first larva, after Fullarton.

is

ponte
tee

ete! 5
eae

ete

2

21

the next ecdysis the limbs undergo practically no change, but
the larva acquires its characteristic spines. It is now called a
zoea. During the so-called zoea stages the posterior limbs are
srowing, but typically remain rudimentary until the ecdysis
which reduces or obliterates the thoracic spines and broadens
the carapace in the formation of the megalopa. In these respects
the Brachyura are in agreement with the Thalassinidae and the
Stenopodidae, and some of the Anomura only differ in that after
the first few ecdyses the third pair of maxillipeds attain develop-
ment, becoming, like the first two pairs of maxillipeds, swimming
legs. It is in this state, also, that is to say, with eight pairs of
limbs, that the Caridea are hatched typically. In all these cases
it may be suggested that the name protozoea should be given to
all the pre-megalopa stages, in other words, there is no zoea stage.

As has been noted in the case of the Penaeidea, the physio-
logical difficulties in the formation of the last two pairs of limbs
of the thorax, that is just where the abdomen commences, leads
to a hesitation in the development, resulting sometimes in the
suppression of the limbs. The effect is seen in other groups. The
zoea stage may be thus defined as larvae with pereiopods or with
all the segments and limbs complete to the tenth, eleventh,
twelfth or thirteenth. We may thus include the phyllosoma
stages of the Loricata with eleven pairs of appendages, still retain-
ing for convenience, however, the name phyllosoma, the erichthus
larva of the Stomatopoda, with ten pairs of appendages, as well
as the larvae of the Homaridae, which are typically freed with
all the limbs to the thirteenth fully formed. Even the first stage
of the lobster although it possesses thirteen pairs of limbs has
been styled a protozoea.

The successive stages give time for the appendages not
developed at hatching to grow, and as has been apparent, it is
convenient to define the stages in succession when groups of the
limbs attain a functional condition. The nauplius has three
pairs of limbs, and during the metanauplius ecdyses, while the
nauplius limbs retain their prominence, the next four or five
limbs are gradually reaching their full development. As soon as
this has been accomplished the larva may be called a protozoea.
A further series of ecdyses give time for the thoracic limbs behind
those already developed to become prominent, and when the

22

whole of these or such part of them as are to be developed at this
period are completed the larva is a zoea. A physiological pre-
cocious appearance and growth of the uropods may take place
in the later protozoea stages. When the pleopods in turn have
become fully developed the larva is a megalopa. Although the
limbs at this stage are complete, several ecdyses are necessary
before the limbs attain the adult character.

The pelagic Euphausiacea (fig. 5), like the pelagic Penaeidea,
are hatched at the nauplius stage, but they attain the megalopa
condition through stages which are far from being parallel. The
metanauplius stages lead to the calyptopis, which possesses
six pairs of limbs. A further series of ecdyses brings about the
addition of the seventh limb, and also the uropods. This stage
has been styled the furcilia. It is a typical protozoea. One or
two more ecdyses convert this into the cyrtopia, which has eight
pairs of appendages, and two other ecdyses bring about the
complete development of the limbs, and the megalopa, which in
this case is not very different from the adult, is established. The
calyptopis is peculiar, but it is followed by stages which are
typical protozoea, and a zoea phase may be said to be absent.

The Mysids, Amphipods, Isopods and their allies undergo
development in brood chambers, and are usually liberated in the
megalopa condition, but in some cases as zoeae. The eggs hatch
in some in the pouch as nauplii, in others at a more advanced
stage, but even in these latter the nauplius stage is indicated.

Nebalia is reared under the protection of the bivalve carapace.
A nauplius stage is passed through in the egg which is hatched
as a zoea with all the thoracic limbs completed, and the larva
is liberated in the megalopa state.

With the exception of Cyclestheria of the Phyllopoda and the
Cladocera, which have parthenogenetically produced young in
the summer, the Entomostraca are liberated as nauplii. The
ecdyses bring about increase in size and a gradual appearance of
the limbs in the usual order.

The sum of my plea here is that I consider the stages in
Crustacean development can be best defined by the number of
appendages, which in the successive stages have reached a func-
tional condition. I venture to propose therefore the following
stages :—-

Figure 5.

Euphausia, after Sars.

23

Nauplius, three pairs of appendages.

Protozoea, more than three pairs but not more than eight
pairs of appendages.

Zoea, more than eight but not more than thirteen pairs
of appendages.

An obvious objection to the scheme is that Euphausia, for
example, iz bound to pass through a, zoea stage to reach a megalopa
condition. But I have chosen to define the stages with reference
to a state of full development, for the reason that if we take into
consideration the appearance of all the appendages we should
want to define not four stages but some sixteen. I hope at least
in drawing attention to the problem I have paved the way to a
solution, and that writers on the subject will cease from calling
by the same name such obviously different stages as the newly
hatched larvae of the crab and the lobster.

2.—GROWTH.

The preceding section will serve to explain the modification
of the nomenclature which is employed here to distinguish the
larvae. The larvae, as has been seen, are hatched with a certain
number of appendages, and a series of ecdyses allow of the develop-
ment and the growth of the remaining limbs. This is accom-
panied by an increase in size. After the larval stages have been
completed, the subsequent advances in growth are brought about
by further ecdyses. These as a whole gradually become separated
by longer intervals of time, but the intervals are also subject to
some degree of variation by season, the ecdyses tending to be
more numerous in the warmer months. A sudden increase in
growth takes place usually at each ecdysis, but a continuation
of growth may take place during a short period after the ecdysis
has occurred. It might therefore be more accurate to express
the increase in graphs such as those which have been made to
illustrate this section by steep curves, but as the growth which
succeeds the ecdysis is small compared with that which is the
result of the process and the time with reference to the instar is
short the growth is expressed as accomplished at the ecdysis.

BRACHYURA.—The growth of the shore crab, Carcinus maenas,
can be stated with an approach to accuracy for G. Brook and Mr.

24

H. J. Waddington, of Bournemouth, have managed to rear many
examples in a state of confinement through a large number of
ecdyses. When these experiments are analysed and _ brought
together, it is at once apparent that the successive advances in
growth and the periods of the instars are intimately related. The
information with reference to the majority of the series has been
given in full by Williamson (1903), and it is restated in Table I.
For convenience of reference the series are distinguished by the
figures and numbers employed by Williamson and by the letters
given by Brook. It will at once be plain that in the table I have
arranged as well as I was able the respective series with reference
to the ecdyses with a view to obtaining mean results, and these
were afterwards smoothed. In each case the size is given and the
number of days occupied during the instar of that size. By this
means the results of season are eliminated, and it is possible by
this method to eliminate also the influence of sex. But the sexes
exhibit an interesting difference in growth, and in this case the
results for each are shown in detail, for the point is important
enough to warrant its being emphasised. The smoothed results
are expressed in the form of a chart in fig. 6.

As has been stated already in the previous section, the crab
is liberated from the egg in the protozoea condition. The seven
pairs of limbs are practically fully developed. The first ecdysis
yields the first of the so-called zoea stages, but it only differs from
its predecessor by having the spines so characteristic of the larvae
of this group. During the four stages the remaining limbs appear
and grow, but they do not reach a functional state until the ecdysis
which produces the megalopa. Hach successive larva employs
the first two pairs of maxillipeds as natatory organs, the limbs
posterior to these are not brought into use. The larval spines
do not constitute a zoea, and I venture to submit therefore that
all the larval stages preceding the megalopa are or should be styled
protozoea.

The fifth ecdysis gives rise to the megalopa. The dorsal
spine in the case of the shore crab is not developed at this stage,
and as a rule it is rudimentary in Brachyuran megalopa. The
carapace is broad and flattened, thus approaching the adult con-
dition, but the abdomen is still directed posteriorly. The limbs
are now fully developed and adult-like in appearance, situation

25

and in function. They still present certain spines, which, like
those of the preceding stages, are employed to assist in ecdysis.

The protozoeae are pelagic, and the megalopa is still to a large
extent pelagic, but it is beginning to take an interest in demersal
conditions. The protozoea stages may be said to last about a
month, and thus for a period of a month or six weeks the shore
crab is undergoing a denatant migration along the coast. At
the end of this denatation in the megalopa and the first young
stages it is showered in immense numbers on the bottom for the
most part between and just beyond tide-marks.

Ecdyses succeed one another rapidly during the first year of
life, as is apparent from Table I. and fig. 6, but these take place
in the sheltered condition afforded at the bottom. During the
instars moreover the young crab is advancing into shallow water.

26

= 0:29
s1vdk Z 0:29
SOL G-9F
v9 ¢-96
OF F-08
TP CVG
69 L-06
29 T-91L
¢9 0:&T
GS 2-01
66 G:8
tT 0-9
¥8 6-F
FL 0-P
0G Ts
0G 6
FL 9-1
= 0-1
“WU
“sAUC ‘AZIG
‘Uvo

eee

SsIvok Z

AjIeou
€0L
9
TG
ES
0&

Maal hee te teed Se ti

0-29

0:29
GOP
O-LE
0-08

8P G2-08 a Say bar,
6F GG =a = ae
601 0:16 sa = ae
L9 GL-GT =r a ar
g9 G61 — a mee
Iv GL-6 — = Ka
TG 96:8 = = &
ai G69 i a TP
mae — a as T8
= = == VIP 68
—— = tL 96.3 1G
= = = 86:6 9G
=F — ad = 8T
“TU “UU
*sAUq *OZIG *SAUCL ‘OZIG “SARC
"3& “1Z oacl

“WOSUICTTTEM = MA ‘UOJAUIPPUM ‘C'H=Z

‘CELVIS LON XOS— I WIAViL

GST =,
9-TT -
6:8 are
1:9 =
OG $8
OL-P 6G
60-6 9G
GEG cy
91 OL
£6-0 =

“TOU

“OZIG ‘SARC

“WU

“OZIS

‘yoolg ‘Y=1

LV

‘sosA pon.

TAINO WIN OM OS

N of =H 16

ret

qeiy
edo[vsoy

¥I0Z0JOLT

=a == ay ad = a ae == —o = a ani ee oa = ie aaa =e = 6G AT
= —-] 0-89 mae Ose st aa = = aaa ed a ree at oa — | 0-g¢ mam OLS 1G 9T
996 GS | &-6F PGE | LTS ay oo ae ate = a = = q-8¢ G6G | G-8P LST | 0:8% 0G GT
GPL ISL | 0-GF 90T | GIP aad — a7 0-6F ag a ae GP 69 GOP OL 0-98 SLT | 0-6€ 6. FL
TT9 GL 9.8 $9 GE —s ina Tg 0.98 ee —— 6P 0-88 OTT | 0-248 69 0:66 8P 0-GE 8ST &T
96S a) 6-93 gg 6:96 — 0.86 =a 0.92 ar os GG 0-96 48 G66 LE 1-86 OF G-GG LT 6L
PLP 19 GIG 89 L1G OP 0.66 a a ae G96 Iv G81 T8 0-16 SEI | 0-61 OS 1-61 9T IT
SIF 69 9-9T T9 T-9T = 0.9T cae as POT | 9-61 GG 0-F1 tay GOT GL 0-ST G&S G-GT ST Ot
PPE T9 1-61 82 9°61 ar oma = - PPL | 0-FT PP 0-61 aa GST 8& O-GT 98 LGL FL 6
8G $G 6-6 cP G-6 =—= = ae aes VG 0-01 — | 0:6 — a 6§ G-6 €2 G6 €T 8
663 6& 8-2 8& Leh a aa aoe ae 81 G-L rg a —— rn OF G8 Lg GL 6L 4
O6T cg &-9 FP G9 — a = cad —— ghi(OEt) ae = = a = G9 &P 0-9 (51) 9
ccI 9G 0:¢ VG 0-9 — = a — as = = — <= ae coo aa VG 0-G OT g
611 9G L°§ 182 LS =a eo — a ee — = ee Sms — nae a TY L& 6 v
£6 ST 0-§ tI 0-§ <= ome re an a = — = = erm ce oe ial 0-& 8 €
82 tL &°% tL GG at a and ora mas oe = a = I = as —- GG Z G
$9 FL 9-T = == =< aaa — = ai = = = == —— = = am = 9 I qeip
OG GL |¢6-0 <= oa = = a ame = ca oa = = = = = = = G vs edopesoy
8& EE Z-0 rae ae = = rz Fe = a ar = = — as ar = = t c
LG Or 9-0 a a, coe? ao ra oa a a a — — — aa — = = € F
LT 6 G-0 —= as == a a —— ae a —— a ae = — = = a G g
8 8 F-0 a oar: am as am a =F ma = aa — Ger a aan = arr T G
0 0 €-0 — == ns a — = a a a — a = ar = a = 0 LT %90Z0}0I1g
‘au wu wut uu “UU wut “WU UU wu
‘sAvq | *ozIg | ‘skeq | ‘aztg | ‘shud | ‘ozig | shed] ‘ezIg | ‘shud | ‘ozig | *sheq] ‘ozig | ‘skuq| ‘ozig | ‘sheq| ‘oztg | skeq]| ‘ozig bs
"OBY ae oN i me, s.
a
“poyjoourg “URaTT ‘7a waa! "3d (9) 01 (f) 26 "29 “sb a

UOSWUTTEAM =A “UORSUIPPUM “C H=S “NoIg YP=1
‘WIVNGI—1 WIAVL

086 | O92 | 2-9
0&2 | OTT | 9-Lh
F19 68 | G-0F
GoG | FL | G-E8
TSP | 8g 6:96
68 | GP 8-06
TSE && L-9T
8T& Té GOL
L486 | 8& 9-6
GhS | Ch 9-4
L06 &P 6-4
POL GE L-¥
GéL be 6-€
801 LT Gs
16 CT 9-%
92 6 0-%
69 real iSfajE
OS GL |96-0
8& EE L-9
LG OL 9-0
LT 6 G-0
8 (oh v-0
0 0 €-0
“UlUE
*sAvq | *azIg
‘ODV
*poyyoourg

ae g-6¢
9ST | 0-ES
POT | O-LP
8P 0-86
16 G-FG
06 0-61
GG com
&6 GGL
6G 0-01
8g 0-8
C6 GL
6g 69
v9 Lv
Té 0-7
9G G-€
GT 0-&
ai G3
“UU
‘sAGq | ‘aZIG
mG

OD Hu & ©

N

oO

‘sosApow

qemy
vdo[vsoly

I %v00z0}01g

9ST | 0.89 ran aed i, ar ag rae = = ae ans = = = or
POT | &-8P =F = = 0:9¢ — eS [Oca ro cae mam as = =
48 LIP = ane 80L | 0-TS 68 0-LE OIL | 9-SP ray —— == = = ae
GZ 0-GE aa, =F G6 0-66 GOT | 0-66 FL g-GE = ee me Saree = =
T9 96 = 0-18 tg 0:66 9ZT | 0-86 Lv G86 SP 0-8@ ae = ai =
8S L-06 ge 0-€6 16 0:06 91 ¢-8T LL 0-GG TE 0-GG a 0-06 se ae
86 6-ST Té G-LT = GPL a g-cT Té SHOlE 96 O-LT 6T 0-$1 = 0-81
6& 6-61 == 1 I (heral Seam Free sae = 66 GGL GE 0-61 LE 0-éL ine ¢.ET
&& 6-6 a. ae = = <a az CG G-6 86 0-01 8- G6 cé 0-01
OF 6-2 i, ay aa ae eae so] sr G-9 98 0:8 81 0-2 6G GL
SP 8-g <= ia = = ae cag OG 09 98 g.¢ LG 4.4 GL L.G
OF G-F a a —_ a a sae VG 0g bv O.P = Lv vI GY
SI 8-& rat — =s aa —y mo TL G-P a gg a sr St GS
LT GE oe aa mix &L OF —— || ers aa = él GG
Sil 9-6 ra “ad i are ria =a GT 0-& aoe eae a = tL 8-1
€L O-G = aad ar =a él 0-G a a car a ST Oat
él Beil a. aa ail = = a aa am aor’ mad an ag rea [rl
= 6-0 = a = os mars coal = a a 6-0
“wu “THU “UU “UU CU “TU UU wu
“‘sAUC | “OZIg | SARC | ‘OZIQ | ‘sAvq | ‘ozIg | “SAuCE| ‘oZIG | ‘skVq| “oZIg | ‘skveq | ‘ozIg | “skvq_] ‘ozig | ‘skvq | *ezI9
“UvOTN “TN "TA IN ra! | (¥) <8 "26 Kal!
a ee Eee ee el ee
“MOSUILTTIAM = AL “UOPSUIPPUM “C “H=S ‘Yoo ‘O=1

,#e

‘CIVA—I WIAVi

Ss m4 3
: PEELED COI a Oe ell fi sl Oo yl Gl at GB esse
‘ ‘ \ | \ [ | rode ee ee is ear (ce i ES os ea oe
| ee ee ee ae ee mere cs
| cae a) pee ae
~ { s 1 ’ Ae f Le) H ; f : He
C ie = | a. wa os ag eee — == alias wa tp —— — Va 8 | |
iene | ar alates ee
I | Mola «cane : i ea Li |
‘a ! | A ye ae eA
Cif 4 bare i ee ana ce ge weg oe ee 0
| | ‘ Ae a Hi a
' ! YA | A ' F pot ay |
! sie ee ee
oy ee cra ka — a oo = f a oy ee ag ++ :
; | ' L ' £ } ! ; ia sheer bo
J t 4 ' ! , eal apiece ry
\ | fe | ' ' |
' of | ;
er aaa ara 7 ae i pices © ae eee
— i | i fyi fi ee
! é ! '
a a | oo
aan Eee eee ree) eas | ee eS 2 ee
Se Le ~~-4

3
|
A or ee
|
|
|
=
| |
eee
i |
ia

it

t
J
4
i
!
!
t
:
I
1

SVNAVAW SQNIOUVO

i _ =| eS _- ==
te- -—- — r ee ove foto

‘) ANNDIG

a

‘=

Pall

29

In fig. 6 the upright lines represent the successive ecdyses,
the horizontal lines in step-like successicn the instars; the whole
lines refer to the female and the dotted lines to the male. The
numbers below indicate the numbers of ecdyses, and along the
margin at the right to the length in mm. and the weight in gr.
The upright lines numbered 0, 1, 2 and 3 refer to the age in years
from the time of hatching. The curved lines express the weight
in grammes, the upper being that of the male.

It is quite plain remembering that the chart has been prepared
with a close approximation to the observed facts, (1) that the
periods of the instars are gradually lengthened, (2) that in the
first year there are fifteen ecdyses in the case of the female and
seventeen in that of the male. The male thus obtains a start in
erowth which it does not afterwards lose. Another point inci-
dentally evidenced is that although the crab remains during the
instar of the same size it is constantly increasing in weight.

A summary of the facts brought out in the chart is given in
Table IT.

TABLE II.—GROWTH OF CARCINUS MAENAS.

Number of Ecdyses. Size in mm. Weight ip gr.
Year. | - | :
Female. | Male. Female. | Male. Female. Male
a 15 17 16°6 20:8 125 2°8
2 4 4 42:0 47-5 18-7 25°6
3 2 2 58-0 60-0 40:8 45:2

This gives the mean results based on the available material.
There is a great deal of variation, due especially to the long spawn-
ing and hatching seasons, but it is evident from the experiments
in rearing which have been made that the effect of season on
growth in the case of the late hatched “ 0” group is compensated
for by an acceleration in the “‘1” group. With this in mind we
can say with some degree of reason that maturity in the female
takes place at about the twenty-first ecdysis. At the time of the
ecdysis, when pairing occurs, the ova are in an undeveloped

30

state, and time must elapse before they are ready for extrusion.
The period of incubation does not appear to be a long one, but
as I stated in 1902, it is not likely shorter than four months.
It is probable therefore that a year is taken up at least in these
processes, that, in other words, the next ecdysis after that in
which pairing occurs for the first time will be at the end of a
year. It will be noted, however, that at about the period of
the twenty-first ecdysis a long interval is bound to occur, for
growth would not warrant an earlier ecdysis. These and other
correlated points will gain in clearness by a consideration of the
growth of the edible crab.

We do not yet possess full information as to the larval history
of the edible crab, Cancer pagurus, but so far as we know it appears
to be precisely similar to that of the shore crab. The protozoeae
have seven pairs of functional appendages, and the pelagic stages
which lead to the megalopa are completed in about a month or a
little more. The megalopa gives place to the first young stages,
and we have to thank Cunningham for drawing attention to their
remarkable likeness to Atelecyclus. The evidence upon which
an estimate of the growth is based was presented by Williamson
in 1904 and by me in 1905. It consists of three series of stages
reared by Mr. H. J. Waddington at Bournemouth, two of which
refer to females, the third with the sex not determined, William-
son’s careful records of the crabs collected in the region of Dunbar,
and the observations made at Cullercoats.

From the Waddington series we can see that a female may
attain a size of 30-35 mm. in a year after hatching, and 46-56-5 mm.
in two years. From Williamson’s measurements of the crabs
of the beach at Dunbar (fig. 7) it may be seen that during the
summer, from May to July, crabs of about 20 mm. appear between
tide marks, that they reach a size of about 30 mm. in August and
September, and 40 mm. in October and November. We see some
evidence also that the larger of these leave the inshore during
the succeeding winter months, reappearing, however, to some
extent in the spring and summer.

Taking these observations together we have the means of
fixing the general growth during the first two years, and we can
see also that there is a wide range of variation. The later stages

~ ”
are eee Se: See

4

|

ars |
_. a a -

5 i
|

f
\

wl

J \
ehh ae 8 Ie Mee oat NE eT ee ee

pom t a a ener cme

:

i

"
=

)

ny

.

j
i
‘,

)
3 .
%
%,

_

FIGURE 7.

wo
2 SEE a ee ee) ee

ANCER PAGURUS.

31

have been determined by the observations on larger crabs watched
for periods long enough to allow of at least one ecdysis taking
place, and by the results of marking experiments,

The chart of growth (fig. 8) which is submitted here to indicate
the mean growth of the female of this species may not be absolutely
accurate, but I do not think it is far from being so. It is almost
precisely the same as that given in 1905. In this case I have
ventured to picture growth over a large number of years, so as to
permit of the discussion of several points of interest connected
with this species and Crustacea in general.

The spawning season of the crab appears to be practically
the same all round the British Islands. It may be said to last
from November to February, only varying in different .regions
by being a little earlier or a little later. This at all events is true
of the Cornwall region according to Cunningham, of the east coast
of Scotland and the north-east coast of England from the informa-
tion derived by Williamson and by me. Hatching takes place
from July to October. From this it may be gathered that the
incubation is one of about eight months, and experiments made
on the Northumberland coast have demonstrated that this is about
the length of the period.

After hatching, the protozoeae are subject to a drift along the
coast for about a month or six weeks, and as has already been stated,
the megalopa and the young stages which follow it reach the
bottom, not usually inshore but in moderate depths outside. They
gain the inshore region for the most part during the second year.
After November of the second year they leave the tide region,
and some return to the shore in the following summer. A few
may return in the next one or two summers, but the majority do
not again venture between tide marks. Outside, however, they
repeat on a larger scale the inward and outward migrations. The
population of crabs as a whole migrates offshore in winter and inshore
in summer, as is well-known to the fishermen. As a result of
marking experiments it has been proved that the mature female
crab migrates before coming into berry, that is to say, before
spawning, in a contranatant direction. The Northumberland
crabs, for example, migrate for the most part to the southern
side of the Firth of Forth, but some reach the north side, or a part
of the coast still further north ; two have been recaptured on the
southern shore of the Moray Firth, at Banff.

32

This is the only Invertebrate of which we have actual know-
ledge of such a migration taking place, but it is probable that some
of the other and at all events the larger Crustacea and the Cepha-
lopod Mollusca have the same power.

A summary may now be given of the growth of the crab,
as presented in fig. 8.

TABLE II] —CANCER PAGURUS (FEMALE).

Year, |Number of} ize, Weight. Gain in

Ecdyses. Weight.
Mm. Gr. Gr.
al 14 25 4 4
2 4 63 25 21
3 2 92 75 50
4 ] 112 170 95
5 1 131 270 100
6 0 131 365 95
7 if 156 455 90
8 0 156 540 85
9 0 156 620 80
10 it 183 695 75
if 0 183 767 (2
2 0 183 837 70
13 0 183 905 68
14 1 210 971 66

The chart and the table may be and they are not intended
to be more than approximately correct, but even so what they
demonstrate is of importance with reference to a species of con-
siderable economic importance, for when all is said it is the Hanae
of the inshore fisherman. |

According to the scheme set forth in both the table and chart
a female crab bears berries three times between its fifth and its
fourteenth year. Apart from theoretical considerations relating
to growth we have facts to prove that such intervals actually
occur. It is well-known that the two-year period characterises
the smaller crabs. The evidence for this has been given in
previous reports ; the results of observations of crabs in confine-
ment and of marking experiments. Even theoretically apart
from such facts it is plain that the annual spawning which has been
assumed to take place is impossible. At the period of casting,
which in the years immediately preceding maturity takes place
in the autumn and continues at and after maturity at the same

33

season, the ova are in an undeveloped condition and remain in
this state practically during the period of hardening, a period of
some months. The crab therefore cannot spawn at the next
spawning season, that is to say, about the end of the year. It is
postponed until the spawning season of the following year, a period
of some fifteen months after the ecdysis at which pairing occurred.
In consequence of this hatching will take place in the summer of
the second year, and casting immediately thereafter; thus at
the end of a period of about two years. It was tempting to say
without the material we are now considering that in this case
growth had to wait on reproduction, but it is evident that at the
stage of first maturity growth is in adjustment with the needs of
maturity.

There is proof likewise from our marking experiments that
a female crab after an ecdvsis may remain for a period of over two
years before spawning, vide Report (new series IV., p. 40) for an
account of a specimen returned from Dunbar, measuring 15-2 cm.
Similarly in the Report (new series V., p. 7) the record is given
of a female which after an absence of three years and five months
was in March berried. This specimen measured 18 cm. We
have the proof therefore that spawning may be postponed over
the periods demanded by the chart. It may be said that we have
no proof that in these cases spawning may not have taken place,
that during this period of years there may have been two spawn-
ings. This is a possibility which must not be overlooked. In
the case of, let us say, a female casting at seven years old spawning
could take place about January, after she attains eight years, and
again about January after she is nine years. Williamson offers
some considerations to indicate that such an event takes place.
He has shown, for example, that the spermathecae are not
entirely emptied -of their contents in the berried female, and
that a second lot of ova could be fertilised after the first had
been hatched. That this takes place sometimes even if rarely is
of considerable interest for it indicates that the periodicity of
reproduction tends to be maintained.

On the other hand we have evidence to show that it is not
common, that as a rule spawning only takes place once during
the instar. In the Report (new series III., p. 74) referring to
the results of marking experiments it was pointed out that in

34

the female crabs which had not migrated the ova were small in
size, Whereas in the females which had migrated the ova were
approaching the size of maturity. This tended to prove (1) that
the migration was due to the development of the ova, and (2)
that the condition cf the ova in the non-migratory females pointed
to a postponement of the spawning season. Besides in our experi-
ence no matter how large the crab hatching almost invariably is
succeeded by an ecdysis.

If this latter aspect of the condition in question be found to
be the general one it is evident that the ripening of the gonads does
not take place in such cases until the approach of the spawning
season, that is to say, according to the conditions given in the chart
until in the one when nearly nine and in the other approaching
thirteen years. Furthermore it is clear that not merely the rate
of growth is slowing down but in association therewith the ripening
of the ova taxes place at a longer interval of time. It is admitted
that in some cases reproduction may take place as has been stated
twice during the instar when the instar is a long enough one to
permit it, but it is manifest that the periodicity of the ripening
is controlled by somatic growth, or rather that ripening is slowing
down in association with the decline in growth. It may yet be
shown that subsequent to the age considered four years may elapse
before spawning takes place. Even if it be said that two spawnings
may occur in the instar, it is evident that the sperms have a much
longer period of life in the spermatheca than has been in this and
similar cases considered.

We have thus an interesting correlation between growth,
ecdysis, reproduction and migration. With reference to the last
it is not necessary to state after the work which has been reported
upon before, that it only affects the females.

There is one further point relating to the migrations which
may be touched upon here although it is not the intention to
dwell on this aspect of the subject. The question has been asked,
is there a return migration of the females? It is not at all likely
to be general if it occur at all, for if the above considerations be
accepted, it is apparent that after migrating contranatantly and
spawning and hatching, the female will cast in the new situation.
The evidence goes to show that until she gets the impulse to move
on again she remains where the ecdysis took place, and further
when she migrates again it is still further in the same direction.

35

The fact that spawning in general with reference to this and
other groups is an annual event has led naturally to the conclusion
that all the mature individuals spawn every year. But it is
becoming plain that this is often more apparent than real.

Further information with regard to the crab will be found
in Williamson’s papers in the 18th, 21st and 22nd Annual Reports
of the Fishery Board for Scotland and in the reports of the Culler-
coats Laboratory for many of the years between 1898 and 1916.

Mr. Waddington kindly drew my attention to a series of a
male Mamaia (Maia) squinado which he presented to the College
of Surgeons. The first stage was found on August 18th, 1902,
the first moult took place on October 21st, and the subsequent
history according to the table I now give. I have to thank R. H.
Burne, of the College of Surgeons, for the measurements :—

TABLE IV.

1902. mm. Days.
Aug. 18 ae 3°20 sat os
Oct. 21 ie 4:0 Se) ee

1903.

Mar. 14 aes 5:0 oe 64
May 17 a 6:5 sce 69
INOV; ©2 Me 9-0 Are 64

1904.
wane 5 cat 11:0 Ay. 66
Mar. 11 ee 16-0 sco" PHT
INOWe, 4 ats 19-0 Sats 113

1965.

Feb. 28 oe 24-0 wee —
May 13 ete Died See —

It is a tropical species common throughout the Mediterranean
and the neighbouring Atlantic, and reaches the southern coasts
of Britain. How far, and from what point, the larva had been
drifted which yielded the specimen found by Mr. Waddington
at Bournemouth we cannot tell. But it is evident from the
irregularity of the instars that the conditions are not favourable
at the northern limit of its range. No doubt the instars would be
shorter in warmer southern waters, but even so it is worth noting
that the spider crabs, as evidenced by this example, do not reach
maturity until after the lapse of several years.

AnomurA.—A Waddington series of the common hermit
crab, Eupagurus bernhardus, is preserved in the British Museum.

36

It has not been found possible to measure the stages, but the
record is interesting in that it shows that the Anomura may also
take several years to reach a mature condition. Calman in a letter
stated that the last stage of the series is still small in size. The
dates of the successive ecdyses are :—

TABLE V.
Instar Instar Instar

1903. Days. 1904, mage 1905. Days.
June 30... 32 Jan. 31 | 48 Mar. 7 74.
Aug: a... 31 Mar. 19 61 May 20 —
Sept. 1... 50 | May 19 88 May 20 Died
Oct. 21... 28 (Aug. 15) 54
Nov 18... 3D Oct. 8 58 \
Wee Zor. 89 Dec. 5 92

The stage enclosed in brackets for August, 1904, was lost
and the date is not given, but to complete the series it has been
assumed to have taken place on August 15th.

Macrura.—The preceding example belonging to the Anomura
gives evidence that ecdyses may be numerous and size apparently
only slightly increased thereby. There is a Waddington series
of Leander (fabricit) adspersus in the British Museum which appears
to indicate that ecdyses may take place in rapid succession year
after year without any appreciable increase in size taking place.
The particulars are given in Table VI. The measurements given
are the length of the carapace from the posterior wall of the orbit
to the posterior margin. The total length was measured in the
case of Nos. 5 and 38, and was found to be 42 and 49 mm. respec-
tively. The measurements of the carapace as furnished by Mr.
Storrow are given with reference to time in diagrammatic form
in fig. 9. From this it will be seen more plainly that there has
nevertheless been a gradual increase in size. The upright lines
refer to the ecdyses when the increase was noted to have taken
place, and the intervening dots indicate the ecdyses when no
increase in the size of the carapace apparently occurred. If there
was an increase at other periods than those stated it was not
apparent, for Mr. Storrow wrote with reference to the series that

g
E

a-~-SHMmORYHN EMA —

(orem Pn

*

oy

FIGURE

37

Nos. 11 to 23 showed no alteration in size of the carapace, and this
was found to be the case also for Nos. 31 to 42, ‘‘ the whole of which
were measured and were found to be 12 mm. by Dr, Calman and
myself.”’

TABLE VI.—LEANDER (FABRICII) ADSPERSUS.

Number. Date. Instar | size, Number. Date. Instar | ize,
Days. Days.
1901. mm, 1904. mm.
1 April 26 24. 8 23 Feb. 20 53 _—
2 May 20 BY) — 24 April 13 63 11
3 June 26 71 = 25 June TS 36 —_
4 Missing 26 July 21 44 _—
5 Sept. 5 38 _ PHC Sept. 3 37 —_
6 Oct. 13 Bal -- 28 Oct. 10 31 -—
7 Nov. 13 61 9 29 Nov. 10 120 11°5
1902. 1905.
8 Jan. 13 55) —- 30 March 10 85 —_
9 March 9 45 — 31 June 3 48 12-0
10 April 23 45 32, July VAL 98 —-
11 June i 60 10°5 33 Oct. 27 134 —
12 Aug. 6 42 1906.
13 Sept. 7s 45 — 34 March 10 91 _
14 Nov. 1 (al — 35 June 9 39 —
1903. 36 July 18 30 —
15 Jan. 10 75 37 Aug. 18 21 _—
16 March 26 66 —- 38 Sept. 8 25 —
17 May 31 39 — 39 Oct. 3 oF —
18 July 9 30 — 40 Nov. 9 145 —_
19 Aug. 8 28 — 1907.
20. Sept. 5 44 _- 41 April 3 72 —
21 Oct. 19 37 — 42 June 14 40 —
22, Nov. 25 88 — 43 July 24 — —:
Diet. July 26 —_— —

During a period of six years and three months this example
only increased in length from about 42 mm. to about 49 mm.,
and had cast its cuticle forty-three times. The series evidences
that in certain cases moulting takes place quite independently
of growth. It will be noted that while the ecdyses occurred without
intercuption during the long period they were particularly numerous
in 1901, 1903 and in 1906, that on the whole they were diminishing
in frequency. If the cuticle is shed so frequently in this and
probably in similar Macrurous Decapods without reference to
growth except incidentally, and probably also without there being
a necessity for freeing the body from external growth, it is diffi-

38

cult to explain. It is a peons which may be recommended to
the physiologist.

It is evident from the table and the diagram that this specimen
when captured was not a product of the year of capture. It is
probable, indeed, that it was then not less than two years old,
and we have again therefore a valuable instance of the long life
of even the smaller types of Decapods.

An attempt may now be made to present the growth of the
lobster, Homarus vulgaris. The spawning season may be said
to be July to September, and the hatching season, June to August,
but occasional cases are obtained of hatching taking place as late
as October. When hatched the larva possesses all the appendages
fully developed to the last thoracic, and the abdomen is segmented,
the telson being prolonged into forks, and the dorsal walls of the
abdominal segments into spines. A larva with this structure
cannot be called a protozoea; it is a zoea. It moults almost at
once, giving a zoea in which the pleopods 2-5 are developed. At
the next ecdysis the uropods are added. The limbs are practically
completed at the fourth stage, but as a more conspicuous change
takes place at the next ecdysis, and a change of habit leading from
the pelagic to a more demersal life the term megalopa is more
conveniently reserved for that stage which here and in America
is now generally distinguished as the lobsterling. Still further
ecdyses take place before the last vestiges of the exopods disappear
from the pereiopods.

The four zoea stages last from about three weeks to a month
or longer according to temperature. The lobsterling is still to
some extent pelagic, but it periodically comes to rest at the bottom,
taking advantage of the shelter provided.

The lobsterlings measure from 1-6 to 1-9 cm., and have been
found in our tank experiments at Cullercoats from about the end
of July to September. A size of 3:5 cm. may be reached by the
end of September, and of 5 cm. in November. On the other —
hand, we have examples which in the following July were only
5:4 to 66 cm. With this as an introduction the material upon
which an estimate of the growth is based may be presented.
(Table VIT.).

59

TABLE VII.—LOBSTER.
a a a a Ee ee ee eee

Male (W).
» Date. Carapace. | Total | Instar
Length. | Days.
——_—_—__- — —-——
mm.
Zoea 1 9-0 7
2 11:0 8
3 13: 12
| 4 16:0 14
1906. \| Megalopa 18-0 14
Aug. 21 10-0 21-0 16
Sept. 14 12:0 24:5 24
Oct. 9 14°0 28°5 25
Nov. 23 15:5 32°5 45
1907. |
Mar. 14 | 17-0 37-0 11
May 5 19:5 41-0 52
Juiy 14 21-0 44-0 70
Aug. 24 | 23-5 49: 41
Oct. 26) 6:0 55:5 63
1908.
Feb. 17 | 29°5 63-0 114
May 12 34-0 74:0 85
Aug. 16 38-5 84-0 96
Dec. 9. 41-5 90-5 115
1909.
June 8 | 47-0 104-0 181
1904. |
Sept. 16 51:0 110°5 —
» 1905. |
Mar. 29 56-0 121°5 168
pert. vs 64:0 140:0 162
1906. |
“April 21 69-0 151-0 226
Nov. 19 | 78:0 171-5 212
1907. |
July 30 870 191-0 253
1908. |
April 17 | 90:0 | 196-0 285
1909. |
April 8 | 100°0 | 216°5 356
197-0 222-5

July 31 |

| July 11/ 54:0

ANG 267 2735°0
|} 1913.
Wahab = Mal 84-0
Sept. 9 98-0
1914 |
June 29] 115-0
Sept. 21 | 1380-0
1915.

| June 26 | 150-0

Female (C).

Total
| Length.

|
|
|

1911, 29°0
Sept. 27
1912.
Mar. 16 |

Male B.
176°0
1883.
July 182°0
Dec. 203°0
1884.
June | 225°0
Nov. 238°0

Instar
Days.

Female (C).
Date Total
Length.
mm
1911
Nov. 50-0
1912
May 5 55-0
July 15 66-0
LOS *
May 16 | Killeda
Miale L.
190°0
1883.
May 202 0 |
Sept. 226 O
1824.

Instar

Days.

231

Gal

iccidentally

40

The table only refers to such examples as have been kept
over a period. There are besides many records of the sizes of the
early stages, and of the results of ecdyses at late stages. These,
however, do not help us to understand the facts of the tables, which
will come as a surprise to all interested in the growth of Crustacea,
even after the presentation of the preceding examples. The stages
are two Waddington series (W) in the British Museum. The
first is probably a male (1906-1909), the second (1904-1909) is a
male ; two Brook’s series (B) of males; and two females reared
at Cullercoats (C) from the eggs. The one lost on May 10th, 1913,
undermined the stones under which it lay, and one of the stones
fell and crushed it. The other after reaching a size of 150 mm.
was lost in some such similar manner, but the exact cause of death
was not apparent. The Norwegian series of Appelloff referred to
by Williamson (1905) show the same growth as those recorded
above, 2 years 3} ins. (8-25 cm.), 3 years 43 ins. (11-4 cm.). A
second specimen got measuring 4? ins (12 cm.) after casting twice
in the next year reached 7 ins. (17-8 cm.:), and after another cast
in the second year 81 ins. (20-6 cm.). The facts may be broadly
summarised (Table VIII.) to indicate the size at the end of the
respective calendar years of lobsters reared in aquarium conditions.

TABLE VIII.

Male. Female.

mm. mm.
Ist year ... AGG 32°5 sae 35 to 50
PAIS Seen Bares wis 55 5 ose 66 to 73
Ord 5 kee ote 90°5 see 98
4th 955. sss nog lakes} sae 130
Syhay Sy Soc -- 140 —
Gil ss) | eee oo diefalsy troy leds —
THAN Sea are sco lel —
Sth’) 55.42: sss, 196 10/227 —
Oth: 35 i see 566. PP ray PANS ae

The facts of Table VII. have been used to make the diagram
reproduced herewith (fig. 10). In this case no attempt has been
made to smooth the results. The figure shows that the early
stages reared at Cullercoats and the two males reared by Mr.
Waddington follow the same general trend of growth, and the
older stages (B) of Brook’s fit into the record as well. But it is
manifest that if we are to accept these facts as exhibiting truly
the growth of the lobster, maturity is not reached until about

~
ba a
mae
ia) Oy elas atieang Lo-— & u oe
ARV Oe es Se es ee
EE Ree lay
|
——— = = ee oe eee lo,
—_—_————-09
%

2 YEARS.

Figure 10.

4]

seven or eight years. It is probable therefore that in this case
srowth is not accurately indicated by the experimental method.
The growth of the Waddington specimens appears in the winter
of the first year to be deflected from the normal path, and the same
feature is true of the Cullercoats specimens, which may be said
to have suffered during the first and more distinctly in the second
winter. We have then to choose between explaining this as being
due to season or as the result of tank conditions.

Two considerations help us to conclude that the confinement
is the cause of the slow growth. The first is that in the rearing
experiments on a large scale at Rhode Island, Professor Mead
and his colleagues found that the Amecican species, which is so
like our own, reaches in a year a size of 5-5 to 7-3 cm., and in two
years 11-43 cm. It will be noted that the Cullercoats females in
the first year were growing just at about that rate. The other point
is that when maturity is attained in the case of the female a period
of two years must elapse between the ecdyses. The incubation
period is one of about eleven months. After casting and pairing
the female requires a year before spawning, and the ecdysis takes
place immediately after hatching.

It is seldom that berried lobsters under 9 ins. are seen. They
appear to be from 9 to 10 ins., say 21 to 24 cm., as a rule when
they come to maturity. This will mark, as we have seen it to mark
in these and other cases, the point of inflexion of the curve of growth
where the change to a more horizontal phase occurs. It would be
possible with all this in mind to construct an ideal curve, fitting
into it the ecdyses shown by experiment but neglecting the instars.
This, it will be seen, I have ventured to do, and that there may be
no confusion I had better state now that the idealised scheme
of the growth with reference to the female is shown by the line
of small dots, the actual growth of the Cullercoats females by
broken lines, and the actual growth of the Waddington males
by the continuous line. Brook’s series are added to the latter,
and indicated by dotted lines and marked “B.” The upright
figures below refer to the years after hatching, and the sloping
figures to the calendar years. The results may now be sum-
marised (Table IX.):—

42

TABLE IX —LOBSTER.

|
Male. Merinie. | Probable Correction
| | (Female).
Year. | | |
Size. Ecdyses. | Size. Ecdyses. | Size. Ecdyses.

Cm. Cm. Cm.
il 4-4 12 5:4-6°6 11 8-4 13
7 7:4 4 8-4 2 13-0 3
3 104 3 a 15) 2 | 17:6 2;
4 IAL 2 15:0 ? 20-6 i
5 15-1 2 _- -- | 23-0 i
6 19-1 Z — — 23-0 0)
7 225 2 — = 26°2 1
8 23°83 2 — —_ 26:2 0

The male evidently casts more frequently, but during the
years of actual experiment it does not gain thereby an increase
in size over the female. The later stages of the female are known
from actual observation to have instars of several years. And
in this case it has been observed that a female may come into
becry twice in the same instar. It has not happened in our
experience, although we have for many years kept berried females
until hatching took place, and in the majority of cases until the
ecdysis. But Cunningham and Andrew Scott have recorded
eases. It may occur therefore during the later stages when more
than two years intervene between ecdyses.

Some information as to the growth of the Norway lobstez,
Nephrops norvegicus, may be derived from Storrow’s account
in the Report for 1911 (new series I.) Females with newly spawned
egos were got mostly from July to October, the largest number
in September. Hatching was found to take place from May to
September, but for the most part in June. This points, as
Storrow states, to an incubation of about nine months, The four
zoea stages are similar to those of the lobster.

Females become mature at a size of 8 cm., more at 11-14 cm.,
and are caught to a size of 17 cm.; males mature at 10 cm., and
are found to a size of 22 em. or slightly more. Males were found
to be mature ail the year, but the obvious signs of active maturity
were mostly evident in August. This, or say July-October, is

43

probably the time of casting and pairing in the case of the females.
The males cast usually in February, March and April.

The tables which Storrow prepared of the measurements of
large numbers each month show on analysis sizes which stand
out prominently. These have been taken to represent stages
in growth. The results of the analysis are given in the following
table, which may be taken as a tentative attempt to indicate the
growth of this species.

TABLE X.—NORWAY LOBSTER.

Year. Male. Female.

cm. cm,
ail 3 Sus 2:5
2 8:5 He 75
3 13-0 we 10:0
4 16-0 os 12-0
5 18-0 see Bs)
5 19°5 AAC 2
7 21-0 see te

The population of males centre about 16 cm., and of the
females about 12 cm., and they are then apparently about four
years old. It is about this pericd also that maturity may be
said t+ be reached in the average condition, :

The foregoing examples show that the Decapoda have a
long period of development and growth. Maturity is not reached
in some of them until they are five years old, and life may be
prolonged for many years afterwards. It will be apparent, for
example, that a lobster of say 12 ins. (30-5 cm.) is about ten years,
and of about 16 ins. (40 cm.) at least about fifteen years old: one
was caught at Marske-on-Sea which measured 29 ins. and weighed
153 lbs. Crabs also may be reckoned to reach as great an age.
A male crab was found in June this year (1918) to measure 23:2
em. (9 ins.) across the carapace and to weigh 2,500 gr. (5°5 lbs.)
A crab caught at Brixham, now in the Hull Museum, weighed
12 lbs. Such large examples cannot be less than twenty vears old.

In complete contrast to the Decapoda and the Stomatopoda
the lower Malacostraca and the Entomostraca grow to full size
in a short period of time. Some have an annual phase, and others
produce several broods in the year, all of which may become
mature in the one season.

td

In most cases it has already been plain the larval passes
without break into the adult condition. This feature is parti-
cularly evident in the Entomostraca, which remaining small
preserve many larval features. Even the Cirripedia may be
looked upon as large babies.

As conditions are at present, I must content myself with
referring to one example. Dr. Marie Lebour has recently described
the early history of Calanus jinmarchicus from the stages pre-
pared by Mr. Crawshay at Plymouth, and she has been good
enough to send me the following measurements :—

Nauplius Stages. Copepod Stages.
i a a Cee Sa i ee MO eee

Q'21 0:27 O42 048 O51 [0-67] G8 12 415 %418 28 [2-9]

At the twelfth stage the young Calanus is fully developed,
all the limbs being completely formed. One or two more ecdyses
appear to be necessary before the adult size is attained. The
larval stages were found to be passed through in about two months.

If the development was equally rapid all the year a maximum
of six broods could be said to be produced. But we know from
the results of plankton investigations that this species and Cope-
poda generally increase enormously in numbers in summer, and.
the increase of the young and the nauplii is particularly noticeable
about May and June, and again is observed about September.
Reproduction then undergoes a special intensity in spring and
autumn, and this periodicity appears to be referable to the period
of growth in the summer, and points to a diminution both in
reproduction and growth in the winter.

It must not be forgotten, however, that this and the other
pelagic Copepoda are holoplanktonic, and that the double wave
of Copepoda observed in the Irish Sea, at Plymouth and at Cuiler-
coats is a general one affecting the whole of the North Atlantic.
It is the inshore manifestation of a change which is oceanic in
its scope. Gran sees reason for believing that this species at least
only reproduces once a year, that there is an annual spawning
season, but the facts appear to point to the event happening at
least twice, the annual phase being a short summer followed by a
long winter generation. In tropical waters the generations are
probably still more frequent, and it is from the tropical Atlantic
that the North Atlantic obtains its annual supplies.

45

Although growth takes place by a series of saltations it is
evident that it is similar to that of other groups of which we have
knowledge. 1. There is a steady diminution of the rate of growth
from the beginning of development. 2. Growth is not uniform; it
is subject to external and internal conditions. It is well known
from experiment that changes in temperature are of great import-
ance in varying development and growth, and the effects have
to some extent been illustrated in the above analyses. In the
case of a species spread from the Mediterranean to the north of
Norway the life-history both in respect to development and
growth is liable to a gradual change from the tropical to the more
Arctic limit of the distribution. In one or two cases I have attempted
to depict the ideal growth apart from external circumstances.
But it is clear that the environment is always bringing about
variation. ‘The ideal, in other words, may not ever be reached,
circumstances are always at worl to produce change. For the
North Atlantic region generally we can predicate a summer of
rapid growth and a winter of slower growth, and we have evidence
to prove that in many cases the result is not always ideal or even
average, that there is an actual slowing in growth which leads
to the reflexion that one of two things must happen, either the
size is stunted or life is prolonged.

In concluding this section it is a pleasure to record, in addition
to that already acknowledged, the help I have received from Dr.
Calman, of the British Museum of Natural History, and from
Mr. Storrow who devoted a day from duty to measure many of
the series utilised in the foregoing presentation. But above all,
I might be allowed to say how much we all owe to George Brook,
and especially to Mr. Waddington, for the series of preparations
they have made showing the history of many examples of
Crustacea for periods extending as will be noted, often for several
years. Miss O. M. Jorgensen, M.Sc., kindly made the drawings
(figs. 2-5) of the larvae of various Crustaceans for this paper.

46

PLANKTON OF THE SUPPLY TANKS OF THE
DOVE MARINE LABORATORY.

By OLGA M. JORGENSEN.

An investigation of the contents of the supply tanks was
made from May, 1917, to May, 1918, in the hope that it would
yield a satisfactory indication, both quantitatively and quali-
tatively, of the micro-plankton of the sea at Cullercoats, but
as the method has been found to have many disadvantages, and
owing to too little time being available for the work, only a very
general account can be given.

At first the water to be examined was drawn from the
Laboratory taps, and a certain amount, usually 1,000 ce., filtered.
The contents of the filter paper were washed in a known quantity
of filtered sea-water, and either examined straight away or
centrifuged first. This was found to be tedious and unsatis-
factory, after which the centrifuge only was used, the method
employed by Dr. Marie Lebour at Plymouth being adopted.*

Samples of sea-water were obtained by lowering a large can
into the supply tank until it dipped just sufficiently below the
surtace to become filled. The water was then well stirred before
being drawn off with a pipette and run into the centrifuge tube.
Samples were taken and examined once a week whenever possible,
the temperature, height of water in the tank, and the weather
conditions being noted. No samples were taken during the month
of December.

The samples were found to consist almost entirely of Diatoms,
Peridiniales and Protozoa, with an odd Nemertine, Copepod
or Pygnogon appearing occasionally.

DIATOMS.

On the whole, the average number of diatoms for each month
gives a curve similar to that recorded for Plymouth* and the
irish Sea,f that is to say, there is a smaller autumn maximum
and a considerably higher spring one (see fig. 1). The autumn

* “The Microplankton of Plymouth Sound.’’? By Marie V. Lebour, D.Sc.
+ Herdman in “ Lanc, Sea Fish. Lab. Reps.” for years 1907-1917.

Sa oS.

47

maximum occurred early, viz., in August and the spring one in
April. Although the general shape of the curve corresponds to
Dr. Lebour’s, we find that the actual numbers of diatoms vary
very considerably. At Plymouth, the number of diatoms in 50
ce. of water at the autumn maximum was below 900, ours being
slightly in advance of this (1,100 in 50 cc.), but while at the spring
maximum only 2,000 diatoms per 50 cc. were obtained at Plymouth,
our average was 8,000 per 50 cc. The number may, of course,
represent the numbers to be obtained in the sea at this time, but
it is possible the number in the tanks is higher than it ought to
be at this time as a result of resting spores formed in autumn
settling in the mud on the tank bottom and giving rise to numbers
of new diatoms in the spring. No attempt has been made to
prove this, but it seems reasonable in the case of Nitzschia clos-
terrum at least, as quantities of small specimens were obtained
in April and May. Also, it must be remembered that the tanks
are not entirely emptied each day, so that a certain number of
diatoms will always be present from previous pumpings, together
with those pumped in each day.

Another disadvantage of using the tank water for this
investigation is that large diatoms like Biddulphia spp. and those
occurring in tangled masses, e.g., Chaetoceras spp. evidently fail
to get into the tanks in anything like representative numbers, as
these two genera occurred at rare intervals, and then only in
small numbers. This is evidently the case with other genera
also, for though the actual number of diatoms present in the
samples is high, the number of genera and species recorded is
much lower than those in the Plymouth samples or in Cleve’s
work.*

A list of the species of diatoms which occurred in the samples
is included in the present paper (Table I.) with the months
in which they are present, and a note as to whether they appear
as solitary individuals (x ), are rare (r), in fair numbers (f), common
(c), or very common (cc), and in addition to this the monthly
averages are given for the commonest and most frequently
appearing genera (Table II.), together with a number of others
which occur at odd times in fair numbers, or which are present
in greater or less quantity throughout the year.

; * P. T. Cleve’s “ Plankton Researches,’’ Kongl. Svenska Vetenskaps-Akademiens Hand-
linger, Bander 36, No. 8.

48

TABEL I—SHOWING THE RELATIVE QUANTITIES OF HACH SPECIES OBTAINED FROM THE
SUPPLY TANKS DURING EACH MONTH,

1917, 1918.

Species. sf

June. | July. Oct. | Nov. | Jan. | Feb. | Mar.

i ns

Diatomacee—
Melosira jurgensii Ag. ... Hf
5 borreri Grev. ... | —
; nummuloides Ag. — —
Paralia sulcata (Ehr.) r f
Skeletonema costatum (Grey.) r x
Thalossiosira hyalina (Grun.)...) — r
», decipiens (Grun.) | x os x --
Leptocylindrus danicus (Cleve) — — — r
Hyalodiscus stelliger Bail. x —:
Coscinodiscus radiatus Ehr. ...| r x if
r —
— x
f at ah
< —
— 4
f r
>< —_

|
x, PP rp soy ps |
os |
1 | | |
PSI ie |
jmexps |

io] mat 4

ie excentricus Ehr.

_ lineatus Ehr.
Actinoptychus undulatus (Bail)
Rhizosolenia setigera (Brightw.)

3 shrubsolei Cleve ...

3 calcar avis Schultze
Chaetoceras sociale Lauder

- gracile Schiitt

53 radians Schiitt
Eucampia zoodiacus Ehr.
Biddulphia sinensis Grev.

3 mobiliensis (Bail.)

Bs aurita Bréb.
Fragilaria striatula Lyngb.

a5 cylindrus Grun.

Thalassiothrix curvata Castr. ...

Lalita in il cnael tact

leash

3; frauenfeldii Grun. ...| x x

of nitzschioides Grin. ...) — aa
Asterionella bleakeleyi W. Sm. = f

Grammatophora serpentina ti —

Fuhr. |

Navicula fusiformis Grun.

iy
53 spherophora Kiitz. ...) —

‘ binodis Ehr. ... c
Pleurosigma acutum Norm. x
es angulatum W.Sm.| —
Amphiprora alata Kiitz. Soel) eX

r

35 obscura A. 8. 2
a obtusa A. 8. mae
ss paludosa W. Sm.
= maxima Greg.
Amphora spectabilis Greg. ...
55 arenicola Grun.
Nitzschia closterium W. Sm.
= seriata Cleve...
i delicatissima Grev. ...|

|

ber}

|
Lt 2 Soe een |
meet iiie).] | | > "iat

eee
| Ln}
iene
17 | is
eee.
: ee seta

49

TABLE [,-—Continue2,

ee nn a US a rare = nS STS BEPTPAP Jun weutnensor—anyscsarernvsnoipancwasy

| 1917. 1918.
Species. | -———
| June.| July. | Aug, | Sept. | Oct. | Nov. | Jan. | Feb. | Mar. April. | May.
——- = } —— Lr
Synedra pulchella Kiitz. ool — r x r r r _- — = Cc f
Surirella spiralis Kiitz.... wel o— — — — — — — o == x —
Isthmia nervosa Kiitz. 2 oe = ~-- - a — —- = a —
Rhabdonema adriaticus Kiitz. — |r — — — — — — — x —
Cymbella cymbiformis Ehr. ... — — — — — x — — —- |; — r
Jeridiniales— | |
Ceratium tripos (O. F, Miill.) ... — | — — — — — — — — |f if
furca Ehr. ... of — | — — Cc — v —_ — —
= fusus Ehr. ... eo r r r — —_ — — | —
‘ longipes Gran. Py — — — — a ie — —- | —
Amphidinium operculatum f f Cc r r r ce oa 1 — r
C.andL. | | |
x rotundatum Rages x r —_— x _ — | c ro) — _
Lohm.

a crassum Lohm. | — x — — — r * — | — sah aae
Peridinium pedunculatum ee pee ee Cg Pek r _ a —-|j— _
‘ Schiitt. | | | |

Pe oceanicum Vanh. ...) — —- | — | —- -= — — — —_ _ r

Ss thorianum Pauls. ...| r ce | or ce f r f f — ce XE

S9 conicum (Gran.) ...| — re 7 arr — os a — — r f

3 pellucidum (Bergh.)| — —_— r c — — r f r f r

is orbiculare Pauls. ...! r f r c c f f c r r c

a5 pallidum Ostf. 4...) — a “— — oo 1 a — — — ---
‘Spirodinium fissum Levander...) — >< f r r x x -—— — r if
Glenodinium gymnodinium — cc cc —_—_ ; — — _- — —_— L f

Pénard |
Gymnodinium vestifici Schiitt. | — | r ax sca, ieee < y ie c r cc | f
e.,, eruginosum — f — —- |j— — — —_— —_— bE r
Stein
Oxytoxum reticulum Biitsch. ...). — oa -= f -— — os — — r —
Dinophysis schuetti Murr. and — x — | —_—- |— — — = os — —
Whit,

ac acuminata — —— — r eee — — — —_— x —
Cl. and L.
lorophycecee—

Ankistrodesmus falcatus Ralfs. — ie — — — x — 1 — f f
2rotococcus sp. ies coef — ip x — -- -— — — — f
Wierospora sp. ... ne ee Ss r i Fa a lege ee — c
mophyceae—
Iscillatoria sp. Jee oe) i — —-);— -- a fOS | —e —
igellate—
Jimobryon sertularia ... | — r — — — — — — — — _—
Yarteria sp. ... ma i — = are — a a — — — r
_ icoflagellatae—
| Distephanus speculum(Ehrenb.)) — r — x — — _— _ — x x
‘usoria—
strombidium sp. Pre .) — _— x — i r — — — x
Zuplotes sp. (probably E. — c r r x r x -- fp —_ x
charon Miill.)
Jidinum nasutum Miill. F x — | =k .— a — —_ — _ as _—,

50

TABLE II.—SHOWING THE ACTUAL NUMBERS PER 50 CC. OF THE CHIEF GENERA OF
DIATOMS IN THE PLANKTON SAMPLES,

1917. 1918,
Species.

June. | July. | Aug. | Sept. | Oct. | Nov. ee | Feb. |. Mar. | April. | Mays
Nitzschia a mas sos) oy | £44. 55S 30 53 25 1 5 15 | 1345 | 400
Skeletonema ... a5e coal) ete 19 13 1 20 — — —_ 20 | 5375 | 4833
Melosira ee aa sco, 40) ri 13 6 11 =F Weg — 5 —_ 34
Pleurosigma ... eas aa 1 3! ik 1 af 1); — il 5 420 288
Amphora 5a one eo 1 6 6 1 1 6 10 5 640 73
Paralia 30 Rs ace 6 1 82 25 75 52 | 120 — 95 40 73
Fragilaria soc no Sool} ake 245 238 9 A esl ees 22, 19 25 26
Coscinodiscus 2| 1111] 4\|.2!] 8.| 7 (oer
Synedra Ses Bae 2.| — i iL i 1 1) — — _— 78 11
Rhizosolenia ... = So 1 i 1 3 1 | 2 — = = —
Chetoceras fe... 8 son ced 1 |210 | — | — | — | —;};— | — | Jan
Eucampia ... Ore wel oo = 47 3 | 4 1 lee | —_ —- 10 _
Asterionella ... im eh ile EE) 6 — 2 — | aed = = = =
Thalassiothrix eee Rat | ed 3 ey Sait JS | —- = —| 4
Navacwla rs ee) fate] A Mlophig yet i a6. |e Pe 8| 23

{ : (

An analysis of this table gives the following particulars of
these genera :—

Nitzschia.—This genus is represented chiefly by NV. closteriwm
and a few N. seriata at odd times. WN. delicatissima appeared
very rarely. WN. closterium is present throughout the year, but
is very scarce in January and February. It attains its maximum
in April, when numbers of the short form with straight ends occur
amongst the ordinary long form. (See * p. 152.) This is the
commonest diatom in the samples, and shows a striking differ-
ence from the Plymouth records, where it occurs throughout the
year, but never in large numbers unless entangled in masses of
other diatoms. Here it was very rarely found entangled, and
the individuals were in the great majority of cases entirely
separated. Occasionally two were found together but never
more.

Skeletonema.—S. costatum was present all the year, except
from November to February inclusive. A great increase in its
numbers occurred suddenly in April and May, and it is to this
species, together with Nitzschia closterium, that the spring
maximum is due. The chains of S. costatwm were very short,
the majority containing only four to six cells. A fair number
were, however, ten to twelve cells long.

S. costatum is recorded as being very plentiful at Plymouth,
and as appearing in enormous numbers at Kiel. Jt has periods
of total disappearance at these places also,

Melosira.—Two species of Melosira appeared in the samples
M. jurgensit being the chief one, whilst I. nummuloides occurred
at rare intervals. At no time was this diatom common, and it
was absent from November to February and in April. It reached
its maximum in May and June.

Pleurosigma.—-P. acutum was one of the larger species which
was evidently able to find its way into the tanks easily, as it
occurred practically all the year round. From June to February
it was represented only very poorly by single specimens here and
there, though at no time was it entirely absent, except during
January. In March there was a slight increase in quantity, and
in April and May a very considerable rise in numbers of this

52

species. During these two months the individual diatoms varied
greatly in size.

P. angulatum also appeared occasionally.

Amphora.—This genus was represented almost entirely by
one species, namely, A. spectabilis, which, like Pleurosigma,
occurred in small numbers all the year round, and showed a
sudden increase in April and May. A. arenicola was very rarely
present.

Paralia.—P. sulcata was present in fair numbers throughout
the period, with the exception of July, when it was very rare,
and February when it was not recorded at all. A sudden rise
in the quantity of this diatom took place in August, and it reached
a maximum number in January. The chains in this case were
usually much longer than those of Skeletonema. P. sulcata
appears to be present in this region all through the year without
any marked fluctuations in quantity. This agrees with Dr.
Lebour’s account of the species as it occurs almost all the year
round at Plymouth, but is essentially a winter species with a
maximum in November from which the numbers dwindle but
pick up again in August.

Fraguaria.—F. striatula is another species which is to be
found at Cullercoats at all seasons. It was almost as common
in the samples as Nitzschia closterium, but reached a maximum
height at a different time, viz., in July and August. During the
remaining months it occurred in fair numbers with great
regularity. At no time was it absent from the samples. It is
to this species, together with N. closterium, that the August
maximum of the diatom population is due. F. cylindrus also
occurs, but much less frequently.

ecoeare sp. is mentioned in ee Plymouth list, but is marked

‘rare ’’ on every occasion.

Coscinodiscus—This genus was represented by C. radiatus
chiefly, together with C. excentricus and C. lineatus in smaller
numbers. It was present throughout the year, but never in great
quantities. It appeared rather more frequently during March
and April. At Plymouth it is a winter form.

Navicula—N. fusiformis, N. binodis and N. sphaerophora,
together with small and unidentified species, occurred in small

53

numbers during almost every month, and were rather more common
in May.

The following diatoms are on the whole rare, but are inter-
esting in that they appeared in the samples only during certain
periods.

Syredra pulchella——Present from April to November. Rare,
except in April.

Rhizosolenia shrubsolet, R. setigera and R. calcar avis.—Present
from August to January. Very rare, but rather more in August,
The genus is represented by six species at Plymouth, with a
maximum number in June.

Chaetoceras sociale and C. radians.—Qccurred very rarely in
June, and rather more commonly in Avgust. The genus is a
common one in the Plymouth records, and is represented by more
than sixteen species.

Hucampia zoodiacus made its appearance suddenly in August,
when it was quite common, and remained until November. It
occurred only once more, in March. £. zoodiacus is present
occasionally at Plymouth from May to October.

Astervonella bleakeleyt occurred during three months, July,
August and October, and was fairly common in July. At
Plymouth it is recorded only twice, in November and December.

Thalassiothrix curvata (with some 17’. frauenfeldiz) was present
from May to November in fair numbers.

Other diatoms occurring still more rarely or at irregular
intervals are included in the general list of species given in Table I.
A few still remain unidentified.

Two of the species recorded, namely, Surirella spiralis and
Cymbella cymbiformis are fresh water forms.

PERIDINIALES.
Members of this group appear in the tank samples in numbers

which give a curve very similar to the Plymouth one, the greatest
nimbers being present in July and September here, and in May

54

and July at Plymouth. The increase takes place with great
suddenness at both places. (Fig. I.)

Here again, as in the case of the diatoms, we have to record
a much larger number of individuals, namely, 5,000 per 50 cc.
at the maximum, as against 1,000 per 1,000 cc. at Plymouth,
and, again, I consider that the number in our samples is abnormal.
This feature is noticeable during the whole period, and would seem
to be due to the numbers of Peridinians remaining in the tanks
between successive pumpings and reproducing repeatedly in the
confined space. Their quantity, too, is not depleted by their
forming food for higher organisms, so that, together with the
numbers regularly pumped in from the sea, this gives us an extra-
ordinarily high proportion of these forms in the tanks.

From July to September the numbers ranged from 1,000 to
5,000 per 50 cc. In February and April they touched the 500
line, and rose to 900 in May, but during the remainder of the
time the numbers of Peridiniales present was never above 200
per 50 cc. Even when least plentiful the numbers are consider-
ably in advance of those given by Dr. Lebour for the corresponding
months. From her curve we find that at no time between
October and May do these forms reach the 100 line per 1,000 cc.
Evidently the tanks are always a most unreliable source of supply
for the estimation of the Dinoflagellate population of the sea.

An analysis of the records shows the commonest species of
Peridiniales in the tanks to be Peridinium orbiculare and P.
thorianum, which occur in greater or smaller numbers all the
year round. The former appears with greatest frequency from
September to January, and the latter in April, May, July and
September. P. pellucidum is common between September and
January, and appears in small quantities during most of the
remaining months. It is by these three species chiefly that the
September maximum is caused.

Other species which occur fairly regularly are Glenodinium
gymnodinium, Spirodinium fissum and Amphidinium operculatum.
Further details of the occurrence of the last-named species are
given in another paper (page 57). A. crassum and A. rotundatum
also occurred less frequently.

The remainder of the species of Peridiniales recorded appeared
in and disappeared from the samples spasmodically.

55
PROTOZOA.

The extreme smallness of some of these forms and the con-
sequent difficulty in identifying them have made it necessary to
leave many of them unidentified, Exceptions were made in the
case of a few very distinctive or commonly occurring species.

The numbers of Protozoa in the samples almost reach the
500 line per 50 cc. in July, at other times varying between 25
and 125 per 50 ce. These numbers, too, are no doubt abnormal.
The appearance of the chief species is recorded in Table I. They
belong for the most part to the Infusoria. A single Svlico-
flagellate, Distephanus speculum appeared from time to time, and
a Flagellate, Dinobryon sertularia, occurred very rarely.

ALGAE.

The Chrorophyceae were represented most frequently by
Ankistrodesmus falcatus, which appeared in small numbers at
irregular intervals, and rather more frequently in May.

Protococcus sp. occurred rarely, as did a species of filamentous
green alga, possibly Microspora sp.

The Cyanophyceae were represented on two or three occasions
by short chains of Oscillatoria sp,

METAZOA.

It is evident that almost the whole of the Metazoan portion
of the plankton is prevented from entering the tanks, as only
odd specimens appear here and there in the records.

ConcLusion.—It will be apparent from the foregoing account
that an investigation of this kind cannot be carried on satisfactorily
by the use of the supply tanks of the Laboratory as a source
of the samples, but will have to be done by means of water samples
or tow-nettings from the open sea, or preferably by both methods
used simultaneously. Large species fail to gain admittance to
the tanks, Dinoflagellates are able to multiply too rapidly in the
tanks throughout the year, and Diatoms evidently succeed in
reproducing too copiously during the early part of the year to

. 56

give a fair idea of the numbers present outside; but the results
give a fairly satisfactory idea of the relative quantities of the
species which get into the tanks, as the curves correspond in
general shape to those of other investigators. The numbers they
represent are too high, however, although such a condition is very
desirable for the purposes for which the tank water is used
ordinarily.

The method used could no doubt be adapted satisfactorily
for determining the depths at which various species of diatoms
occur normally when undisturbed by storms, and far enough
from the shore to be unaffected by breakers:

Totar Flawk ton.

tee

va Near
‘
070208 ALGAE

‘.
vf
‘i

DIOG NI SWSINHDYC Jo HIEUNY

Figure lI.

1917-18.

Plankton of Laboratory Tanks.

=
| :
> 2 :
: 3
’
- = 7
) a
= >
7 |
be 1
>
.
~
= : |
7 +
e . 7 7 ‘es
E ; |
re a=
- d — ? “a
a > : = : } ;
| . —
- |
7
’
; : |
2 oe -
; hee a et aR
| i
=
*
.
’ es |
- =!
; | |
| @
; ’
x
+4 . -
H
¢ oie a) A :
Ls 3 |
o bat 7 - cl .
: :
i 7 | : |
as :
z : ; ;
:
ie 3

4 4 rz
‘ P > F
=
7 i Reg
Jo SE. = =e
| y S
= a c |
: ar
7 SD Se ae ee
BE SP SPOR ms oad g Fy“: La? ae a nee One EF RS ee
ee a ae ol eee ye ee z 23 ‘ :
i
r |
sty ne
: .

57

OCCURRENCE OF AMPHIDINIUM
OPERCULATUM AT CULLERCOATS.

By OLGA M. JORGENSEN.

Previous to the autumn of 1917 this form was recorded from
Cullercoats Bay on only two occasions. The first time it was
noted was on May 25th, 1913, when Mr. Storrow * observed small
patches ‘of sand coloured by Amphidiniwm operculatum at the
north side of the bay. Jt remained for several days. It was not
noted again until the next year when Mr. T. Whitehead + gave a
short account of his observations. A. operculatum occurred on
the foreshore in much larger numbers than last year in two
patches N.E. and E. of the Laboratory, and a few feet below
high water mark. These patches proved to be an almost pure
culture of the species, and consisted chiefly of encysted forms.
These patches persisted until the end of September. (When
they were first observed is not stated.)

Although I had noted the occurrence of Amphidiniwm in the
plankton samples which J examined from time to time, my atten-
tion was not particularly attracted to it until September, 1917,
when a sample was brought into the Laboratory from the north
end of the bay, where it occurred in patches on the wet sand.

From this time the characteristic brown patches were looked
for at frequent intervals, but not until November 29th did they
appear again, when wet stretches of sand below the Laboratory
were covered with faint brown markings. On the following day
a tour of the foreshore was made from the north side of the
Laboratory to the south end of the bay, when immense quantities
of Amphidinium were found to be present throughout the tidal
zone, wherever water remained on the surface of the sand. A
number of sandy pools among the rocks at the high tide mark
showed still larger quantities, lying in deep brown patches on the
sand. There did not appear to be any inthe water. The examina-
tion of a sample showed that these forms were very active.

* ** Report of the Dove Marine Laboratory. Cullercoats,’’ 1913.
J ‘ Report of the Dove Marine Laboratory, Cullercoats,’’ 1914.

58

The drier portions of the beach were free from the brown
patches, but from one of these a scraping of sand was taken about
14 inches deep, brought into the Laboratory and covered with
filtered sea water. Next morning the surface of the sand was
covered with Amphidinium.

During the same day, December 1st, a thorough examination
of the beach was made again. The sand in the pools was now
more thickly covered with the brown films, which were becoming
buoyed up in the water and leaving the sand altogether in many
cases. The patches were still as prevalent on the beach from end
to end of Cullercoats Bay, but there was no sign of the Amphidiniwm
on the Tynemouth sands or beyond the northern breakwater.

These and further observations continued up to the time of
writing (May, 1918) are not in accord with Whitehead’s explana-
tion that the Amphidinia sink into the sand when covered with
water—in fact, the reverse is the case, for whenever water was
present on the surface the brown patches oecurred, while they
were entirely absent from the drier regions. That the Amphi-
dinia sink into the sand when it becomes dry is shown from the
result of moistening the scrapings of drier sand.

On December 2nd, the Amphidinium had diminished some-
what in quantity, and on the 8rd had vanished ertirely. The
total disappearance may have been due to some extent to a heavy
gale which occurred during the night.

From December, 1917, until May, 1918, the records of the
occurrence of A. operculatum in Cullercoats Bay are as follows :—

Dec. lst.—Plentiful on wet sand; thick film in pools.
by 2nd.—Decreased in quantity.
es 3rd.—Disappeared.
Me 6th.—Present in small quantities.
Le 8th.—Disappeared.
», 13th.—Plentiful on sands and in pools (spring tides).
, 14th.—More plentiful.
», | 15th.—Heavy films in pools; disappeared from sands, present
in scrapings.
Jan. 5th.—None visible.
- 21st.—None visible Very severe weather; entirely absent
» 2drd.—None visible. from scrapings and water samples.
Feb. 9th.—None visible.
», 1l4th.—None visible; very scarce in samples.
», 20th.—WNone visible ; rather more plentiful in samples.
= 21st.—None visible; rather more plentiful in samples.
» 20th—None visible; none from examination of samples; two
individuals obtained by centrifuging 8 ces. of wate.
» 26th.—WNone visible ; very few in sample.
», 28th.—None visible ; very few in sample.

59

Mar. 2nd.—None visible ; very few in sample.
20th.—None visible ; very few in sample.
» 2ord.—Faint traces in pools.
24th.—Patches smaller and fewer but deeper in colour.
25th.—Only two faint patches in pools.
26th.—None visible ; fairly plentiful in sample.

» 27th.—A few small patches.

», 380th.—None visible ; fairly plentiful in sample.
April 3rd.—None visible : fairly plentiful in sample.

; 2ith.—Patches very few and faint.
May 2nd.—None visible ; in fair numbers in samples.

From the above records it appears that during the last six
months at least, Amphidinium has been present on the foreshore
at Cullercoats continuously, its entire absence being noted on
January 21st and 23rd only, although it has appeared in sufficient
quantities to make it conspicuous on only four occasions. Further
observations will probably show results similar to those made
at Port Erin. Professor Herdman, to whom I wrote on the sub-
ject, says, “ Amphidinium has appeared off and on in abundance
during the last ten years, and is scarcely (if ever) altogether absent.
. . . . We have now stopped recording it at Port Erin as it
seems to be permanently established on the beach.”

Though we are not yet in a position to make definite state-
ments as to the causes of the apparently erratic appearance and
disappearance of A. operculaitum here, it may be of interest to
note that on the four occasions on which it is recorded as being
visible to the naked eye there have been spring tides; this is
exactly the reverse of Professor Herdman’s observations * in
1912, when he found that Amphidinium was most plentiful at the
neaps. Mr. Storrow, too, in noting its occurrence in 1913 states
that it “gradually disappeared with the advent of the spring
tides.”

I have not observed any alternation of Amphidinium and
Diatoms here (see *), but in one case where a sample of sand and
water was kept in the Laboratory for some three weeks, the
former, which was visible as a film in the water, sank down after
a time and the Amphidiniwm was found to have been replaced
almost entirely by diatoms. It was present, however, at the edge
of the jar about } inch below the surface of the sand.

** 26th Annual Report of the Liverpool Marine Biological Committee,’ 1912.

60

NOTE ON THE LARVAE OF GRANTIA
COMPRESSA.

By OLGA M. JORGENSEN.

At the beginning of September, 1917, specimens of Grantia
compressa were obtained containing embryos ready for hatching.
The free swimming stages were secured from these both naturally
and by the use of the centrifuge, and the followmg observations
made.

On September 3rd, a few of the sponges were attached to a
wire fixed in the mouth of the centrifuge tube, which was then filled
with filtered sea-water, and centrifuged for ten minutes. A
number of actively swimming amphiblastulae were thus collected.
They appeared as shown in fig. 1. Next day (nineteen hours
later), some of these were still active, but a greater number had
ceased to swim about, and the larger granular cells had begun to
multiply. A few appeared to be developing normally (fig. 2),
but the majority had evidently been affected by the centrifuging
and were growing irregularly. These took various forms, some
of which are indicated in figs. 3-6. Ten hours later all had ceased
to be active.

On September 5th, all the larvae were dead except two which
had settled down—the granular cells having overgrown the
columnar ones. (Fig. 7.) Two days later they appeared as in
fig. 8. They were apparently unchanged next day when they
were probably dead, as on September 10th they had disappeared
entirely.

When the first batch of material was centrifuged, a number
of other specimens were placed in filtered sea-water and left over-
night, when naturally hatched larvae were obtained.

Many of these were identical in form with those hatched
previously (fig. 1) ,while others showed a decided flattening of
the posterior pole (fig. 14). These larvae were more active than
those got by centrifuging—showing a quicker forward movement,

GRANTIA COMPRESSA.

Fras. 1-1a.—Side view of newly hatched amphiblastula.

Fic. 2.—Seme, slightly older. Posterior granular cells beginning to over-
grow columnar cells.

Fias. 3-6.—Side view of abnormal amphiblastulae, showing irregular growth
of granular cells after centrifuging.

Fig. 7.—Fixed larva seen from above.

Fies. 8-9.—Same a day older. Large granular cells dividing to form
epithelium.

+
}
5
»*
I
=
’
r>
.
’

.

ee a ea

61

together with a rapid rotation. They developed quickly into the
form shown in fig. 2, but still remained active.

After twenty-four hours some were still moving slowly, whilst
a few appeared ready to become fixed. Two had not changed
in form. On September 8th a small number appeared to have
settled down as fixed forms, but on the 10th all were dead.

Further batches of material were kept and examined from
time to time, from which it would appear that the larvae remain
active for about twenty-four hours, after which a further two
days gives a complete change from the amphiblastula form to
that in which the overgrowth of the granular cells is complete
and fixation is taking place (figs. 8 and 9).

Some of those in the last-mentioned stage appeared nearly
twice as large in diameter (viewed from above) as the newly hatched
ones.

' The freshly hatched larvae swim at the surface of the water
except when disturbed, when they seek the lower layers for a
time, but as proliferation of the granular cells increases the larvae
sink to the bottom, while still retaining their motile character
for a short time.

In one of the earliest samples an embryo was found to have
hatched prematurely, being still in the typical pseudogastrula
stage. It had not been subjected to centrifuging.

The latest batches examined (September 10th) indicated
that the period of hatching was drawing to a close, as in one case
eight sponges were centrifuged, and gave only about half-a-dozen
larvae.

An attempt was made to rear the larvae, and to obtain the
fixed stage by keeping them in vessels coated internally with
celloidin, but without success. Probably the vessels were too small
and shallow, and the water too still to be favourable to their
growth. The amphiblastulae remained active in the vessels for
twenty-four hours, and it is not likely that this period would be
either much longer or shorter under natural conditions, as it will
be regulated more by the amount of reserve food material stored
within the creature than by small differences in the external con-
ditions—so that this gives the young sponge time to drift a con-

siderable distance from the parent before it becomes permanently
fixed,

62

NOTES ON THE DEVELOPMENT OF
CARCINUS MAENAS.

By OLGA M. JORGENSEN.

A number of berried hens of the common shore crab were
collected from time to time between November and April, and
kept in the Laboratory tanks, and the eggs examined at intervals.
Early in December, some recently spawned eggs were examined.
They were orange coloured throughout, and the cells showed as
yet no differentiation. On January 30th, the same batch of
eggs showed the large black eyes of the embryo to have developed
sufficiently to be seen with the naked eye. An examimation of
the egg at this stage showed the orange coloured portion to occupy
only two-thirds to three-quarters of the sphere. The disposition
of the embryo within the egg can be seen clearly at. this stage,
as the chromatophores characteristic of the Zoeae have been laid
down already. Those of the abdomen form a chain running across
the middle line of the thoracic region, showing the “ tail’ to be
curled round the body. Unfortunately, it is impossible to give
any further account of this batch of eggs, as the crab escaped
from the tank. |

Another crab examined on April 26th had eggs apparently
almost ready to hatch. It was isolated in a small glass tank,
through which compressed air was bubbled, and on May Ist a
number of larvae were found. These were carried round and
round in the current induced by the compressed air, and when
removed into a Petri dish some were found to propel themselves
fairly actively, whilst others lay on their side, the only movement
being a spasmodic jerking of the limbs.

T'wo separate batches of larvae were kept in this way in the
hope that some might be reared through all the larval stages,
and some definite records of the length of each stage arrived
at, but when two moults had taken place the laboratory attendant
shut off the compressed air, with the result that the larvae sank
to the bottom of the jars, and next day most of them were found
to be dead, and some were covered with a thick growth of Vorti-

63

cellae. The experiment was repeated with the same unfortunate
result. Attempts were made to feed the larvae by adding cultures
of diatoms and Amphidinium to the water. At the time of
writing the experiment has been set going a third time.

The three stages obtained—the Protozoea, and Ist and second
Zoeae of Williamson *—are represented in figs. 1 to 3 of Fig. II.
(page 20), and the time taken between the moults when the
larvae were in these stages is given below for the first two batches

of material.
First Bator.

May lst (afternoon ... ... Protozoea found, beginning to hatch.

May 2nd (morning) ... ... Anumber of protozoeae isolated, only one
had moulted in the afternoon.

May 3rd (afternoon) ... ... Some protozoeae still present, many
moulted, and now in first zoea stage.

May 5th (morning) ... ... About equal numbers of first and second

zoeae present, no protozoeae found,

SEcoND BatcH.

May 5th (morning) .... ... Protozoeae isolated.

May 6th (morning) ... ... A number of protozoeae present. First
zoea stage chiefly, with a few second
zoeae.

May 7th (morning) ... ... Only one living protozoea found. First
and second zoea stages in about equal
numbers.

May 8th (morning) ... ... Some first zoeae still present, chiefly
second zoeae. No protozoeae found.

May 9th (morning) ... .... Only second zoeae found.

This makes the length of the first larval stage (protozoea)
between twenty and thirty hours, and in one case as long as forty-
four hours approximately. The second stage or first Zoea appears
to last from forty-eight hours to seventy-two hours (a few longer
than this.)

These observations are strikingly different from Williamson’s,
He states that the protozoea stage is of very short duration, and
that on leaving the egg-capsule the larva casts «immediately.
He continues, ““I have not noticed the Protozoea stage in cases
where the larvae have been hatched out in a tank, but it may be
got by washing the egg-mass of a female during the time the young
are hatching.”’

I think that very possibly Williamson’s statement as to the
very short duration of this stage may be due to the fact that it

*“2ist Ann Rep of Fish. Bd. for Scotland,”’ p. 136.

64

is much less active than the following stage, and that unless the
vessel containing the larvae is arranged so that there is a continual
current sufficient to keep them suspended they will sink to the
bottom of the tank, and most probably be lost in any sand or
mud there, though, no doubt, there is a good deal of variation
in the length of time during which this stage may persist.

As regards the length of the first Zoea stage our observations
at Cullercoats are again divergent from Williamson’s, but in the
opposite direction—-that is to say, that while we find a longer
protozoea stage, the period during which our larvae remained
as first Zoeae is considerably shorter than his, viz., forty-eight
hours to seventy-two hours here, whilst he states that “‘ Zoeae
of the first stage which hatched on May 15th moulted into the
second Zoea stage between the 24th and 27th, that is, after not
more than twelve days.” This difference is interesting, as it
shows a considerable variation in the duration of the second stage
too, and, no doubt, the same is the case in the subsequent stages.

In completing the series of figures of the later larval stages,
modifications of Williamson’s* and Faxon’s} figures have been
used, and an attempt made to indicate the relative size. William-
son gives us no actual measurements of the first four stages, but
takes the distance between the peints of the dorsal and rostral
spines as the basis from which to indicate the relative sizes of these
stages in his drawings, but this gives no indication of the relation
between the size of the last Zoea and the Megalops, the size of
which he gives as 2-5 mm. broad and 2-7 mm. long (Brook’st
figures for this stage are much smaller, viz., -93 mm. and -43 mm.)

My own measurements for the first three stages are as follows:—

IProtozeeca. | se. ... ‘+7 mm. long (average cf seven specimens).
First Zoea 2 ... 1:95 mm. long (average of seven specimens).
Second Zoea ... ... 2*1 mm. long (average of seven specimens).

This shows an increase in size smaller than that suggested
by Williamson’s drawings, but supposing the larvae to increase
at about the same rate in moulting into the third and fourth Zoea
stages, this fits in very well with the size given by him for the
Megalops, and it is on these figures that the relative sizes of my
drawings are based. The last two figures are taken from those
given by Brook.

+ “ Bull. Mus. Compar. Zoology. Harvard,” Vol. VI., p. 159.
t ‘‘ Ann, and Mag. Nat. Hist,” S. 5, Vol, 14, p. 202,

65

FAUNISTIC NOTES.

Nematoscelis megalops, Sars—On March 28rd, 1918, large
numbers of Schizopods were found dead in the sandy pools at
the high water mark in Cullercoats Bay, and on the next day
they were observed in even greater quantity on the beach between
Monkseaton and St. Mary’s Island. On March 25th the same
forms were still present, but had been carried higher by the tide,
and were fewer in numbers than on the previous day.

An examination of the least damaged specimens showed the
creature to be Nematoscelis megalops, Sars., which is an oceanic
form occurring in the North and South Atlantic. It is recorded
also from the Indian Ocean, the Mediterranean, off the Labrador
and Nova Scotia coasts, and in the Irish Sea.* This appears
to be the first record of the occurrence of the species on this coast.

Sars gives the greatest length of N. megalops as 26 mm. The
largest obtained here was 20 mm. long (fig. 1). This species is
characterised by the great length of the first pair of legs, which
terminate in a group of bristles. The tail also corresponds exactly
to that figured by Sars, as does the arrangement of the gills (figs.
2-4).

Amongst the N. megalops collected at Monkseaton a number
of Euthemisto compressa, Goés, were found.t These were
evidently the large form of the species, the average length being
13 mm.

This species occurred much more sparingly on the beach
than did the Nematoscelis, and was not observed at Cullercoats.

Sars mentions EH. compressa as occurring off the Norwegian
coast, in the Arctic Ocean and Davis Straits, and near the east
coast of Greenland. The large variety is found in the Nozth Sea
irregularly, but its occurrence as recorded in previous reports is
interesting. The small variety appears every season.

O. M. JORGENSEN.

* * Nordisches Plankton,’ VI., Schizopoden, and *‘ Report of the H.M.S. ‘ Challenger, ’
mI, p. 131.
T Sars’ “‘ Crustacea of Norway,’ I., pp 12-15.

oy

‘3 >

66

Caligus curtus, Miller —On October 30th, 1917, two codling,
about 18 inches long, were brought into the Laboratory, and
from their heads eight specimens of Caligus were removed. Seven
of these were females, with an average length of 8-1 mm. Five
of them bore complete egg-strings, which averaged 9-6 mm. long.
The remaining individual measured 11 mm. in length, and was a
male. The copepods were quite active after removal from their
host, and were observed to bear large numbers of white leech-like
creatures round the edge of the carapace, and large bunches of
club-shaped objects at the end of the body on the ventral surface.

In colour they were pale yellow and profusely patterned with
dark red irregular-shaped chromatophores, especially along the
edges of the carapace. None of the specimens showed any blood
in the alimentary canal.

It was not without some difficulty that the species was finally
decided upon, as the creatures bore considerable resemblance to
both C. rapax and C. curtus. In the general form of the
body the females correspond very closely to that of C. rapaz,
while the greater size, and the length and general character of the
ege strings are decidedly those of C. curtus. Also the male exceeds
the female in size—another characteristic of C. curtus—but does
not do so to such a marked extent as stated by C. B. Wilson.*

Working from Wilson’s descriptions and arranging the char-
acters of our specimens in two columns according to their likeness
to one or other of his species, we get the following :—

C. curtus. C. rapax.
Carapace longer than wide.
Anterior margin only slightly
rounded.
Lunules large, orbicular, widely
separate and projecting.
Eyes small, situated forward.
Setae and spines present on first First antennae large, tips nearly
antennae. equal extreme width of carapace.
Length of female = 8:1 mm. (8-12 mm.)*
Length of egg strings = 9°6 mm. (14
min. )*

‘Length of male = 11 mm. (13-20 mm.)*

+ The numbers in brackets denote Wilson’s measurements for C. curtus.

From the table it is evident that these individuals had affinities
with both the above-mentioned species, but I have decided to

* Chas. Branch Wilson. ‘“‘ Parasitic Copepods of North America.”

Nematoscelis megalobe, Sars.

i
'
i
i

Figure 1.

‘ 2 . :
=a nt ve j
4 . : ,
¥
4 ix
‘ “4 A
( &
i y
‘
io
' : ¥
hd hd cl
yg
- - i
s
.
i
‘ .
~
‘
+
Ly
¢
’
,
\ »
é
‘ :
1
- Mt
a
x 7
4
o

4

*
«

‘
SSS

rae =

he

relegate them to the species curtws as, other points being fairly
equally divided, the most outstanding feature, the relatively
large size of the male, marks them out as being nearer to C. curtus,
as it is the only species of Caligus in which this is the case. It
would appear, then, that we cannot draw a hard and fast line
between the two species as we get such forms as these occupying,
‘an intermediate position, and, considering that the two species
occur on a number of hosts, amongst which Gadus morrhua is given
for each species, it would be only reasonable to suppose that the
two species—if they are actually separate species—are sufficiently
closely allied to breed one with the other, while it is possible that
a further investigation of the matter might show that according
to varying conditions of the host, and to differences in its sur-
roundings the parasites approach either the curtws form or the
rapax form, or that they may occupy an intermediate position
between these two extremes.

The parasites infesting the carapace of this Caligus proved to
be the trematode Udonella pollachi, Nob,t the largest of which
measured 4 mm. when fully extended. They remained attached
to the edge of the carapace by the anal sucker, while alternately

contracting and extending the body, and twisting from side to |

side very actively. The eggs of the trematode clustered beneath

the body of the Caligus are each club-shaped and suspended on

a short stalk. : '

Masses of a Vorticeila were also found attached to the carapace

of the Culigus, and in one case a small number had attached them-
selves to a trematode.

| O. M. JORGENSEN.

EXPLANATION OF PLATE.

Fic. 1.—Dorsal surface of female Caligus showing markings and egg-strings.

Fic. 2.—Same from ventral surface showing numbers of Udonella (Ud.)
attached to edge of carapace and to egg-strings, also clusters of eggs
of the trematode.

Fic. 3.—Two chromatophores.

Fie. 4.—Udonella pollachiv.

Fic. 5.—Eggs of same.

{1 Van Beneden, “ Recherches sur les Bdellodes on Hirudinées et ies Vrématodes Marins.”

=

é
4

2 4 ;
phe ee
, ., ‘ ~* + ~ , . bo ;
_ rs | — « -» * ’ wands ‘t * % -~ ..

DOVE MARINE LABORATORY,

_CULLERCOATS, NORTHUMBERLAND.

*

qr HE LABORATORY js fitted for research in Marine

Zoology and Botany. Application for tables should be.

made to the. Director. =

Material for use. an Zeslogical hae may Ae :

obtained, especially fish, crustaceans, &c., as Gadoids, Pleuro- oe

nectidae, Skate, Norway Lobster (Nephrops), Myxine_ from

{oral fishing boats; stages of development of fishes from the

“tanks: and Arenicola, Coelenterates, Nemerteans, Starfishes, 3

&e., from the shore.

| Should special methods. of preservation be preferred,
- timely notice should be given. = oe

The Miztations ‘bh Fish,

By ALEXANDER MEEK,

Peale: of lacy: Arnsisone Callcke - in the. Uwe a
Durham, and Director of the Dove Marine Laboratory, Cullercoats.

With 12 plates and 1 28 other illustrations, maps and diagrams.

xviii. cs 427 pages. | Demy 8vo- - 16s. net. iat

~ Dr, SHIPLEY, F-R.S., in Contig Life. git Fe aaslignitative Se up to ~
“the present date, final work on the migration of fish. One vould: anultiply 2

examples of the extreme fascination of the Yolume.’ ae

Sols Nature. —“A work which no one interested: in ae A
seience or desirous of an up-to-date grasp of some of the —

- phenomena underlying practical Pohery. suckers can 1 afford to.
overlook.” = 1 . Sr eae

Professor. DAVID STARR JORDAN, in The ae Noturalist. _— =
=

-_“ Professor Meck’s studies pass through the whole long series of fish families.
~ For want of space, we may not follow them further -in these pages. We
must give the work, as a whole, very high praise-as carefully, intelligently _

and. actentitcady done, and as constituting a Feferenve. spook oF: reat ing = =

eee

a

LONDON: EDWARD ARNOLD, aw and 13, Maddox street, WwW. 1S —

—~

ee Oe is

BL WHO! Library - Serials

manta amore pin ei faerie testinal era
arat sie stat
ite ae ae Mee ae ian i

aS Hopit ee bet :
eh PLE pata

4
det
hates RAAT ore

+ eee
sks tenet v daeh ip ae

leads
vi

arn | ceed

eat ae peibes ie

ph eeesent Pate is

Cia reat urea a agctaN *.
oat Uy pint

ties Geb epibe be pee hehes

rit re} athe pt bee aiusdaey roy
rer HBS hive Sepehed Ret heyy RO Bey,

ree ei iY Spike Pt Maal a wrote pepe bok eter

ks 20 HAR het | feu At ae 1 ithe ch te been ler

sbostia UReTecaee et its +h fis fis Ao leila DEA
Rae abe baed vert feintet ewe het E pais fh ted me beb lbs Gem
sit he # Frhe gah He ¥ ify

t
hye ie prrsorbvei PE rf ie iy Hs hel rai hebitea oben
pa beeeeond yt My aed Habe fee Vy
‘erin he te pe Bee he Bets, be
He fi

i oa has aye art suetehe rete"

airy

LT aadeed ”

Levan atresia thih er sheet

panera Ft: en iin tare opeh ieee he heh #-
posliamn este’ trad delet ; Mesiadudtienrr te ehibs

Fo as ie ae 5 a * rr oad pee i
ne ooserteat® is it 8: he te pa ead a i
bade ese nt “4 cir wie pei ree a de
{ dhe Ae deer ieee Rh heheheh

a
vies * $ the
" eats Basen
aaa sinit keane Heat

mii atraeed ha of ae pia oe
faa ve atiiat es sae Hs wie ; Fe Pa otntie Ath vectee *

Five vlattoberki wpe ortes bo tf ney Uy

ates of hem Wa eae $e wer alert Fay fh 1, va BB

(re lath egal py a
oft hav ctheg sit Hebe

Batis feeb: Rian tori

Hinhes BHA BE bed Treg
igen Saehiventesteh
‘hee bas ee he
iif fof it
4%

ME a Rats yop yee hee
bah

tae:

ih umslenier rt ‘
265 ot ie ys
Hearaeeeeee

ae Peete i aed

eee

af
f Crate
Ay pele aM

Coste {ne AY

ee i iapaanmitoksoac
f i dAisa y all.
ayia des Me Aero j He eae ee rs
pnd t, Dead o> ped bad OE OTH
re she

te
ies ip

aia fb

cee hte ch iia

nee

sho Gis Pt
: iit ed

3) fr ae ee “h Mitts Wet Md

| ee ae cites ae oe

ise coli est iy ite eieate chet Ur vebet PU thre: eit th Wie ‘ ely sith 4 (" Ae) Fy Ais eo ie

wea. beer preibact bas sede ph bee hints ft she tee reecectrbtee) Phebe RbeW ya Heady

ree ir ene ae CR ATA hacia ted sit nat hati isbinsbebatd ey
wh ihe ‘ * Pett hehehe bor ha 3 e Pe “Ps or 4

MA ate fs of ) lesen View i atid faekaticion oT oo she ona oe

ir ;

EOE nein
rae! aie
eae a

‘ brie
Me
mba $

Bia ving

vt bet p hii r. (ier
dite ate ae ei ant
Of

Pew eRE hae Hite
ERA efits WEA
Pam Ga oe toe
wre

ieee

ibe fe pei abot
See
ihe af thet pe rp ee ea
Syegipheiate: SLi abeeiny amt hepetnin wrnerest er ep
4 eth eae i) ies rw ce

ti STM adage Hi chee 9
eu yay PebeP bw iit

ete a

oe iu Wan
vi if iat 28) Aes L a

ey.
ess

ae

ht
t A Pee i

mii (ein beseca ioe deht bhape kl wat? edie
UE of ' piped ad ies dette
OA fei WP iyi 4 sth
chit “heb pet et : il eres ie rea
i meh ie ae el
tt

a
=

2%

2
=

Pf 2
be Pedi gee etl
ce cut vl

3
ce
ee
24
ats
<
=
ae
4
pte
ae

Sete es Shani air

‘td Ht Hie

seieii aLpheah bh SPAM
i bet t
nina jae rie

sahebed

se ribet at fey! pei re pasty th
t 4 p hibeBi here i
ina a eet ee fi +t if Mette i i et ae PARE ar
Tha riper i ld 4 bebe bo h ge . pints obs ter 4 “
bef iy Hictbiigites fi a rhs liebe pes HEpste bel bebe oe itso ae ie

Neg DE heOt! imams nih ys tdci F
it ith anata eae lit tee
. Pi
fh rt Shier he oi “seh +
he steht neetst pan betebrse teas be rei ie wh:

bape path apeiras ber
tit a # Lak ry ped
ae Beer hy Peeeiel the

itt ie ned oi dk iH eee

vet P04) Bebe is

Bi ewe Be be bt

sou: a Lesh
aay

b Pew oe
Sb) dps iekne ined
eee eee ie be dine $b: of
pipe dt pete aiid ob ute
nee y

hh.
sp itveae ;
Vist Ay bihepe ce

; pad ns
W
vite Pept eed

ue
uth Citi es =

sas W Ea

He ey vi ra
1, keine Ait

et

=
—
=e:

oe

oa tet

te
Soy

fe ti bef nen +heP. Fed or nhs Kee heheerhe v
hd mitt rites aiett “} i ene aie an ht
! ish be he ee P Wt a aie: 1 gthewe
Hiei gabe bs iit: hokebr hob: bei: bbls ke he AT Fe
fbi eh beet site atte fel ia aia 4

jas

9 5 q rbsieboh iepeieaesD t
chbpegeerhek ber
ai Uislsorbrerissangseree bie {

His
Fete
- ss -

o>

Darah pee xy a Shi pie ne Sibel ith bebe tte
New weaned a hn? ua hi ite tae te ;
i ahh ed 4 aah ee ‘ a nity

7
a fe Min A
aii tbe a tie Pieet= tis '
od i Gund ie

aps Of eae Huan fir
heh yew Oe ed +)
Pte era habe evel aedidles
chee aged Hei eae: §
a

5 Am hipee ise
wy fy ene bial 1 ae ¥
' . y

*
Aaeb beb. bike tc eePe OLE Pine beh Pw
thee Beh! Gabeh 1a beiewepede bef tor Php bUp
TL AH dL OAL aL bua aed Laban ae aes
ret nee bebe Speieeihy Fs babii bef F ,
he bei WAiebeait wpe Or be fee a if
te bath bebe ee Gem ite rida ty
tert MAR ed hay

teeber

rit)
Sa pine
Sbeiea

hee aL eT Pe
nnd rt ay ike oe

®
bite bb

5

;
Cada Pt 4
WL Ob LPH»

bites acer
ed ae woe Lage ne

i fanteene ears: ity
t e irteeeesliee ticity Nm

if soi hi Rida padi Lay sth

Penta it ie

vi ?

Dicks isprhek ae

area +f
Ady agen at >
insert Aree
cope Be Sly they

ore ;
hide plas ‘ath ies ie

uae ra sire vb ee bi secret Oa fl

ao hat Dla aaa

na
9 base

44 i
seibe Wb bel We ati ath SN ee
ator Saf dint ner et Hest: Hi sgeit hee dahyp bss pretty
beer ue: - yong 1 i i ise et beh ensee eb4 pt fe LORS Or Poems ibis pet
he Cos a O th ve HEE BE vou iveh Qebsie aathu bees tii Sy pet ber ise he by
Ridges rues fi ait vr i aewet Baebnk é rohan wrt ari Pe abies on
Stem tfiayree LAs tie ath PED PT HIG" BP REL
\s + ? . e

on * rite

ns (ews yee ts
Me te

raebainergcsulartormne| titel ake Beri dags

‘ / J re a + Mb 1h
oat ete Heian pe tthe t ist tt hon here
Pe +4 ' 2 " if ne ahverry
inthy tit eA tiasiiy seared bes ( Puede aasieaseepiarksd hiaee ’ ;
1 Oi tt ly yeti risa A is at eRe ye fee Cina 4 if Bei ok pete abe yr he Ret PU Deh bet is Pt adi
sp iety moot rf ned $4 ire ohare Aes th mae Ly $k hive rth bebe vebinneet artery eee? og
5 yoo ras ¥ eh i
sat mentee v aisha ries itn ; ”

ioeeey Loney wet i

edie
ta us

aca it
cAeepey ah