('LRCADIAN I'ER1Ol)lCTTIES I N PHYTOPLANKTON
355
press) 11nd Goering (it 01. (1973) werv ttblo to estthlish HORIC die1 p t k r i i
in the uptake of silicic ricitl by upwrlling popiilntions, with i i presumed
noon peak.
Cltvirly , t h w O ~ M T V ~ L ~ ~ O I I S
twt' coiiiieett~rl to the rnetabolisni of
Hilicon dtiririg t lie fornicLtion of tlicit,otn Hliell, II problem which hiin been
c~xt~wivcly Htiitliecl by l,c!win ot nl. ( I UOO), I3iisby and Jlc:win (1907),
Coom1)s and Volcani ( 1 !M8) :tnd ao-workers.
Tho observcLtioiis by Miiller-Haeokel (1966) on silica content of a
saline ciwk tm reportwi further hclow (p. 361).
XI1 I. BIOLCTMIN I C S C E N ~
Rrnissioii of light by living phyt.oplnriktoii occurs exclusively
rirtiorig mwiiio tlirioflagcllates untl belongs mainly to the stimulated
type (npontcmcons emission is coiisiclercd a t the end of this section) ;
genera and species concerned arc listed by Sweeney (1963), Loeblich
(1967), Kelly (1968), Airth et al. (1970) and Tett (1971). As a matter
of fRct, bioluniinescence is unknown in other algae and in freshwater
habitatti (one molluscan species excepted). Though luminescent
bacteria itre not uncommon i h t sea, no information is available on
bitcterioplmktoii in this respect ; possibly some of the light recorded
frorri i n nitu measurements is due to bacteria, in addition to dinofl;igellates and zooplankters. Concerning bioluminescence itself and its
mechanisms, the reviews by Chase (1964), Loeblich (1967), Hastings
( I968), Airth et al. (1970) and others may be consulted.
Probably the first example of rhythmicity was discovered by Henneguy (1888) on Noctilum : organisms kept in the laboratory did not
flush during cllbylight hours, though they recovered some excitability
if kept for 30 niinuteu or one hour in t h r dark ; full luminescence was
recovered 2 horirs after sunset ; the author satisfied himself that dark
;idaptt~t,ioii of his own retina wits not involved. Massart (1893) corroborated tlicui: findings and, even at this eirrly date, was able to demonstrate that the rhythm is endogonous, since it persisted under constant
light or dtirkiiess until the death of the organisms. However paradoxic d it, mny ;Lppenr, doubts still arise to-day from this case: NoctiZzcca
rhytliniicity IVHR questioned by Harvey ( I 926) and clearly disproved
by Allniiiii ( l S 7 4 , Nicol (19ri8), Sweeney and Haatings (1962) and
Stveeney ( 197 1 ) . The peculiar proverb that " colorless species have no
rhythms " may work here, though the last author studied " green "
(symbiotic) cells (Sweeney, 1971) ; also, as suggested hg Harvey (1 9Fi2),
different strains may exist,.
Whatever may be the case with Noctilucn, the circadian periodicity
of stimulated bioluminescence has been confirmed by a number of
355
press) 11nd Goering (it 01. (1973) werv ttblo to estthlish HORIC die1 p t k r i i
in the uptake of silicic ricitl by upwrlling popiilntions, with i i presumed
noon peak.
Cltvirly , t h w O ~ M T V ~ L ~ ~ O I I S
twt' coiiiieett~rl to the rnetabolisni of
Hilicon dtiririg t lie fornicLtion of tlicit,otn Hliell, II problem which hiin been
c~xt~wivcly Htiitliecl by l,c!win ot nl. ( I UOO), I3iisby and Jlc:win (1907),
Coom1)s and Volcani ( 1 !M8) :tnd ao-workers.
Tho observcLtioiis by Miiller-Haeokel (1966) on silica content of a
saline ciwk tm reportwi further hclow (p. 361).
XI1 I. BIOLCTMIN I C S C E N ~
Rrnissioii of light by living phyt.oplnriktoii occurs exclusively
rirtiorig mwiiio tlirioflagcllates untl belongs mainly to the stimulated
type (npontcmcons emission is coiisiclercd a t the end of this section) ;
genera and species concerned arc listed by Sweeney (1963), Loeblich
(1967), Kelly (1968), Airth et al. (1970) and Tett (1971). As a matter
of fRct, bioluniinescence is unknown in other algae and in freshwater
habitatti (one molluscan species excepted). Though luminescent
bacteria itre not uncommon i h t sea, no information is available on
bitcterioplmktoii in this respect ; possibly some of the light recorded
frorri i n nitu measurements is due to bacteria, in addition to dinofl;igellates and zooplankters. Concerning bioluminescence itself and its
mechanisms, the reviews by Chase (1964), Loeblich (1967), Hastings
( I968), Airth et al. (1970) and others may be consulted.
Probably the first example of rhythmicity was discovered by Henneguy (1888) on Noctilum : organisms kept in the laboratory did not
flush during cllbylight hours, though they recovered some excitability
if kept for 30 niinuteu or one hour in t h r dark ; full luminescence was
recovered 2 horirs after sunset ; the author satisfied himself that dark
;idaptt~t,ioii of his own retina wits not involved. Massart (1893) corroborated tlicui: findings and, even at this eirrly date, was able to demonstrate that the rhythm is endogonous, since it persisted under constant
light or dtirkiiess until the death of the organisms. However paradoxic d it, mny ;Lppenr, doubts still arise to-day from this case: NoctiZzcca
rhytliniicity IVHR questioned by Harvey ( I 926) and clearly disproved
by Allniiiii ( l S 7 4 , Nicol (19ri8), Sweeney and Haatings (1962) and
Stveeney ( 197 1 ) . The peculiar proverb that " colorless species have no
rhythms " may work here, though the last author studied " green "
(symbiotic) cells (Sweeney, 1971) ; also, as suggested hg Harvey (1 9Fi2),
different strains may exist,.
Whatever may be the case with Noctilucn, the circadian periodicity
of stimulated bioluminescence has been confirmed by a number of