SOME AAI'ECTS OF N E ~ P L A N I A I N MARINE ANIMALS
219
in the anter.ior rnediastin~~tn in Bcilnenopt~rrr 1r~uscu1u.s. Histological
e~aminnt~ion xtiow(~(i H nli~t~rix of collagenol~s tissue in which large
k)undlcs of non-rnc~dolli~tcd and ~nedullated nerves were found. In some
xi*ctions woll tliffercr~tiatctl neurbons were idso ueen. A cerebral nenrofibroma (T'illtlri. 1968) wihs re1)ortect i11 Ij(z2aenoptern p h ? / s n l ~ . TWO
neurofibrornittfi locat8ed at the Ibase of thc ventral paraflocuhu of the
cerebellum were ;~lxo re(-orded by this ibuthor. Both tumours contained a
n~at~rix of collugolious fibres and rrlJcc1 to nome nervous elements.
r 1
I t~ose werib remnsnt,~ of' atrophic niyclinated fibres, together with some
ganglion cells. Pilleri ( 1 966) has previously described a lipoma in the
bane of the brilin of n hlt~qaptem novomn!lliue (Borowdki, 1781), which
WiLS fount1 i ~ t
thc junctioli of the pons anti rnedrllla. The tumour was
hon~ogcnous I L I I ~ contilincd angiomut~oes sl)aces within it. The adjacent
cbhoroitf pltbxns sllowctl ovidcnce of xomc strand proliferation with
i~trophy of t l ~ r
1)i~pillae and. h.yperplnsia of chorioidd proliferations.
Stolk ( I M t i ) described a case of (:ranulorna malignum (Hodgkins
I )isease) in I3olnrr1,optera ph?jsalw. The paper is a disappointing one in
that it spcilds too long discussing the disease in man, which in this
perticulttr (*ontext is irrelevi~nt. Again, the illustrations are poor, and
little cotnrneiit iasn be made. This paper, like so Inany of his fish papers,
is bedcvillrtl by c*ibrneriL lucida drawings which are so stlbjective as to
I ) t h
alrnost vnl~iclt~ss.
Rcco~itly furt l r c ~
sprcin~onx 11i~ve 1)et.n cxamined in this laboratory,
~t~vcrctl of' whic*h canme from the K. R.S. l)iscovar!j expedition. They
includc sevc-rtd i~~tcrcst~ing turno~irs (Pigs 36 to 38).
V I . SUMMARY A N I ) (:~K(:I~LTSION
All the a~iirnnls c.onsitlc~red ill this t~rticlr h a v ~ one thing in common
in that tl1c.y live either totally or partially ill a watery medium, and it is
ciiffioult to dismiss the eflect of the environment on them. There are
lnnny questions which hnve been raised, and only a few have been
answered. The reuson for this is simple: there is much ignorance
surrounding the i~~iinlalv examined. Yet one cannot escape the conclusioli that some of these animals if, and when. suitably investigated,
would possibly show an aetiological agent, either local or general, which
clould be responsible for some of the neoplasias described.
I t is difficult to appreciate why oysters and clam8 do not have
more tumours, particularly when one considers their biology, ecology,
their mode of feeding, and the fact that they are " bottom " filter
feeders. It is an irlteretlting fact that over 10 p.p.m. of arsenic are
permitted in shellfish as opposed tJo land animals. Arsenic is one of the
219
in the anter.ior rnediastin~~tn in Bcilnenopt~rrr 1r~uscu1u.s. Histological
e~aminnt~ion xtiow(~(i H nli~t~rix of collagenol~s tissue in which large
k)undlcs of non-rnc~dolli~tcd and ~nedullated nerves were found. In some
xi*ctions woll tliffercr~tiatctl neurbons were idso ueen. A cerebral nenrofibroma (T'illtlri. 1968) wihs re1)ortect i11 Ij(z2aenoptern p h ? / s n l ~ . TWO
neurofibrornittfi locat8ed at the Ibase of thc ventral paraflocuhu of the
cerebellum were ;~lxo re(-orded by this ibuthor. Both tumours contained a
n~at~rix of collugolious fibres and rrlJcc1 to nome nervous elements.
r 1
I t~ose werib remnsnt,~ of' atrophic niyclinated fibres, together with some
ganglion cells. Pilleri ( 1 966) has previously described a lipoma in the
bane of the brilin of n hlt~qaptem novomn!lliue (Borowdki, 1781), which
WiLS fount1 i ~ t
thc junctioli of the pons anti rnedrllla. The tumour was
hon~ogcnous I L I I ~ contilincd angiomut~oes sl)aces within it. The adjacent
cbhoroitf pltbxns sllowctl ovidcnce of xomc strand proliferation with
i~trophy of t l ~ r
1)i~pillae and. h.yperplnsia of chorioidd proliferations.
Stolk ( I M t i ) described a case of (:ranulorna malignum (Hodgkins
I )isease) in I3olnrr1,optera ph?jsalw. The paper is a disappointing one in
that it spcilds too long discussing the disease in man, which in this
perticulttr (*ontext is irrelevi~nt. Again, the illustrations are poor, and
little cotnrneiit iasn be made. This paper, like so Inany of his fish papers,
is bedcvillrtl by c*ibrneriL lucida drawings which are so stlbjective as to
I ) t h
alrnost vnl~iclt~ss.
Rcco~itly furt l r c ~
sprcin~onx 11i~ve 1)et.n cxamined in this laboratory,
~t~vcrctl of' whic*h canme from the K. R.S. l)iscovar!j expedition. They
includc sevc-rtd i~~tcrcst~ing turno~irs (Pigs 36 to 38).
V I . SUMMARY A N I ) (:~K(:I~LTSION
All the a~iirnnls c.onsitlc~red ill this t~rticlr h a v ~ one thing in common
in that tl1c.y live either totally or partially ill a watery medium, and it is
ciiffioult to dismiss the eflect of the environment on them. There are
lnnny questions which hnve been raised, and only a few have been
answered. The reuson for this is simple: there is much ignorance
surrounding the i~~iinlalv examined. Yet one cannot escape the conclusioli that some of these animals if, and when. suitably investigated,
would possibly show an aetiological agent, either local or general, which
clould be responsible for some of the neoplasias described.
I t is difficult to appreciate why oysters and clam8 do not have
more tumours, particularly when one considers their biology, ecology,
their mode of feeding, and the fact that they are " bottom " filter
feeders. It is an irlteretlting fact that over 10 p.p.m. of arsenic are
permitted in shellfish as opposed tJo land animals. Arsenic is one of the