Distribution of the Red l\!Iarrow m Bones of the Fin \tVhalebyTadahiro Ohe
Department of Anatomy (Prof. Dr. T. Ogawa),
Medical School, University of Tokyo.

The present investigation was performed at Mombetu, Hokkaido, inthe summer of 1948, when I stayed there for ten days. The object of mystudy was to determine the site of haematopoesis in the body of whales,
for then we had in mind a question, whether or not the blood corpusclesof the baleen whales are developed in the organs just as they are in
the terrestrial mammals. Except the quite recent paper of Slijper et al(1948), which reached us after the completion of the present work, there
seems to have been no detailed report upow the distribution of the red bonemarrow in the baleen whales.
Materials:.
Four individuals of the Fin whale, Balaenoptera Physalus L., wereexamined.
All of them were captured off the northeastern coast of
Hokkaido by boats of the Taiyo Fishering Company ; by the courtesy anddeep understanding of the members of this company the present work
could be fulfilled to the success of a certain grade.
Methods:
Of course at the whaling station the scientific research is met withmuch difficulties, as speedy disposition of the whale body is the mostimportant factor in the whaling industry and in most cases the heavymaterials can only be moved by the help of winches. We can examine
them not always to our hearts' content.
My own experience at thatoccasion is as follows. The vertebral column, .after most of the truncal
muscles were cut off, is brought by the winch to the "bone ·platform";the huge mass was separated into each segment, by cutting through theintervertebral discs. At that time I endeavoured to arrange all of thevertebral bones in the natural order, and asked one of the workers tobreak them lengthwise in the oro-caudal direction. Of some vertebrae thetransverse and the spinous process were also cut for examination of thebone marrow. The cervical vertebrae were split longitudinally in a mass.

Tadahiro Ohe

18

The dissectors used to remove the ribs altogether with intercostal muscles
and pleura as a whole from the vertebral column, then to separate theminto each rib and to bring them to the bone platform. At that occasion I
arranged the ribs in the natural order on each side and examined theircaput, cauda and the middle part, sectioning transversely. Though theribs of the Fin whale are said to be usually fifteen pairs, there were twocases Nos. 42 and 40, in which I found only fourteen pairs. The problem,
whether there were really only fourteen pairs, or one pair, probably thelast, was lost at the dissection platform, is not certain. I guess the former
assumption may have more truth.
To my regret, I had no chance to examine sternum and pelvis. I did
not dare to find out these small bones, not to disturb too much the speedy
work at the dissection platform. The chevron bones are carried to thebone platform as a long chain-like block, and I cut some of them to see
the marrow.
The large skull is at first divided by the bone saw lengthwise at themiddle line into right and left halves, cut then in various directions into
many blocks, which are small enough to be easily dropped into the pressboiler. I examined the cut surfaces of them as much as possible. The hyoidconsists of one median part (basihyal and thyroyal) and paired lateralparts (stylohyal). The stylohyal was usually not discovered, as it wascarried probably to another place. I cut as a rule .the hyoid bone in the
median plane and further along its long axis.
The scapula was cut into two parts, a cranial and a caudal. The large
projected acromion was examined especially. Bones of the pectoral limb
were cut in a mass transversely into two pieces, and then in the same
direction into four portions. The head of the humerus was especially·observed.
I made some microscopical preparations from the red marrow andascertained· that the haematopoesis was certainly taking place in it.
Results:
No. of the specimen----- ----~- - - - - - - --------

44!

41

40

I

42

50

I

52

53

I

67

Male

FemaleFemale5 p. m.
Augu!;t 12.

5 p. m.
August g.

8 a. m.
August 12.

------

Body length in feet------------------

Sex

FemaleDate of the capture

8 a. m.
August 14.

!

Distribution of the red marrow in bones of the· Fin whale

Beginning of dissection

6 p. m.
August 14.

Approximate hours elap·sed between captureand dissection
Vertebral formula<U<U

6 a. m.
August 10.

1010

11

7+15+14+20=50

7+15+14+22=58

4 P· m.
August 12.

II

8Not especially examined.

Atlas

The ·red marrow was found only in the ventral arch.

Cervical vertebrae 2- 7

Entirely filled with red marrow, but in No. 44 not so completely as in three other individuals.

Thoracic vertebrae
1-15

Also filled with red marrow, but the white marrowCl) was present in a wedge-like formC2l in the peripheral I part of thevertebral body, becoming larger in the caudal direction.C 3X 4)..a"'.......
>I Lumbar and caudal<U3 a. m.
August 13.

II

19

Beginning with the 15. (in No. 42 with 14.) thoracic vertebra
caudalwards the red marrow becomes irregular in shape andgradually decreases in extent, but in Nos. 41 and 40 it waspresent in addition along the lines of epiphysis. A red spot
vertebrae
was found down to the 2. caudal (No. 44), to the 12. lumbar(No. 41), to the 8. lumbar (No. 40), or to the 2. caudal (No.
I42).
--:Processes-- examinecf
6. thor.+10. thor.+
5. thor.+~ tho<.+"'of some vertebrae ( + :15. thor.14. thor.7.
thor.+ I 10. thor.+
I. lumb.f
presence of the red mar·
10. thor.+row;-: its absence)
14. thor.One red por- ; Though I reTwo small
Theskullpieces of red tion was pre- member to ha- had the redmarrow, each sent in the ba- ve seen the red marrow only
the size of a sal part and ' marrow in the in its anterior
hen's egg, we- another in the i skull, I can not basal part.
Skull
re present in frontwall of the i clearly locate
the basal part, brain case and · it.
and a larger one more in theI
one in the roof occipital part.
of the brain case.

I1-I

Not
Hyoid
examined.

A . relatively : The red marlarge red por- row was pretion in the thy- sent only inrohyal
and the thyrohyal.
scattered red The stylohyal
spots in the. was not obserbasihyal.
ved.
Stylohyal note}l1amined.

The red marrow was present neither inthe basi- andthyrohyal, norin the sty lohyal.

IRibs
Glenoid"'
'3p.
r.n"'

Scapular plateu

The red marrow was present only in the caput. But only inthe caput of the 10. rib of No. 41, the red marrow was mixed
with the white one.
The red spat was seen.
Three very
Hereandsmall spots of there red marthe red marrow row was prewere found.
sent.

Acromion

No red marrow

Bones of flipper

No red marrow

No red m'arrow

20

Tadahiro Ohe

Supplementary remarks to the table of the forego'.ng pages :(1) Man says usually "red" and "yellow" as to the bone marrow, butin the whale, especially in the vertebrae of them, the yellow marrowmight be better called ''white", because in the lumbar vertebrae, forinstance, we get an impression, as if red ink were dropped on the snow.
So I used in this paper, instead of " yellow ", the term " white bonemarrow." But in hyoid, scapula, and bones of the skull the yellowish
colour predominates.
(2) By cutting further, the red marrow was seen in form of an hour-glass.
(3) In the epiphyses of the thoracic vertebrae of No. 42 the red marrowof a patch-like form is present in the center, surrounded by the whitemarrow ; this fact was not seen in the other specimens.
(4) In the 10. to 13. thoracic vertebra of No. 42 the dorsal wedge of thewhite marrow was relatively sharp and small, while the ventral whitepart showed more rounded contour.
(5) The red marrow .in the processes of the 4. and 7. thoracic vertebra
was continued to that of the vertebral body, while that in the processesof the 10. thoracic vertebra showed no direct continuation with that ofcorpus.
Summary:(1) In the atlas the red marrow is present only in the ventral arch. Fromthe 2. cervical down to the 14. thoracic vertebra the vertebral bodies arefilled nearly completely with the red marrow, and as the whale advancesin age, this seems to disappear in the caudo-cranial direction.
Beginning with the 15. thoracic verte4ra the red marrow becomes
irregular in shape and decreases suddenly in extent, but point-like redplaces can be found up to lumbar ·or caudal vertebrae.
As Slijper says, the red marrow seems to disappear earlier in theprocesses than in the corpus of vertebra. In the latter the white ·marrowappears at first in a wedge-like form in the circumferential part, and atthat time the convertion of the red marrow into the white has not yet
finished in the processes.
In the vertebrae of two individuals (No. 44 and No. 41), the redmarrow, irregular in shape, was also present along the lines of epiphysis,
but this wai;; not the case in the other two (No. 40 and 42).
(2) In scapula, hyoid and skull the red marrow becomes smaller with theDistribution of the red marrow in bones of the Fin whale

21age. Slijper et al seem in the Blue whale not to have seen the red marrow in these bones.
(3) In all of the costae the red marrow was present in the caput.
(4) In bones of the flipper and in the chevrons the red marrow is completely lacking.
Explanation of the figures :Except hyoid, lateral views of all of the bones are shown. The processes of vertebrae areomitted ; ribs, hyoid and bones of the flipper are moved from their natural positions.
black·························································red bone marrow.
obliquely lined area···· · · · · · · · · · · · · · · · · · · · · · · · · · · ······bones not examined.

Literature :C. F. Feltmann, E. J. Slijper and w. Vervoort: Preliminary researches on the fat-content ofmeat and bone of Blue and Fin whales. Koninklijke Nede.rlandsche Akademie van Weten·schappen. Vol. 51, No. 5 (1948) p. 604-615.

Tadahit'O ohe