Year: 1873




SEVENTH LECTURE By PROF. AGASslz.
NERVOUS SYSTEM OF INSECTS TOTALLY DIFFERENT


PROM THAT OF NEUTRALITY-SUSPICIOUS. IN


CELLS AND NUTRIMENT AFFECTING DEVELOPMENT


or BEEs-cAUsEs WHICH DETERMINE SEX IN


HYNENoPTERoUS INSECTS.


rYRoM AN OCCASIONAL CORRESPONDENT OF THB TRInUNEl
CANRRIpGE, Mass, May O.--The following
lecture was delivered by Prof Agassz April a. at the
Museum OF Comparative Zoology;


Al the close of my last lecture made some general
statements concerning Parthenogenesis apecaar mode
Of reproduction by virgin females, first Investigated In
sone families OF insects among which the progeny thus
brought forth consists Of males. and OF males only In
the family Phylopods crustacea this process
obtains also but the progeny in this consists on
the contrary females only The department of these
animals ut the time OF reproduction is singular they
exhibit faculties peculiar that they have been tno
objects OF careful observation. Their seemingly inte
gent action. known instinct has been compared Win
the intellectual powers OF the higher animals and even
with the mental faculties Of himself A knowledge
OF the facts therefore important to just discrmn
ton between those faculties which are
by entirely distinct while others regard tnen
as notifications Of one and the same power Hls olteh
said that the possession Of reason places man ABOVE ne
brute CREATION TO which instinct peculiarly belongs anu
yet the facts justify such distincon as we sa
dnd II we study carefully the lives OF some OF these
creatures. - ~ - -, r,s,c-s





rhe beebiye consists, when in full activity OF one
uueen several hundred drones, and many thousand
working bees. These constitute community by when
combined system Of labor carried on transcending IN
many respects the most complicated actions OF man
himself Their structure shows no organ similar TO
those by which the mental functions manifested In
the higher animals and in man. They have no brain
proper nor does their nervous system correspond in
any way 70 that the vertebrates In all vertebrates
the solid front mass of tho nervous system which we call
the brain prolonged backward into long cord known
as the spinal from which many nervous threads
arise and branch spreading through the whole organ
izaon The brain and the spinal cord In fact tho whole
central nervous system, are inclosed In cavity, the
skull and raobIo canal, separate from those in which
the organs OF digestion, respiration, circulation ana
reproduction cOntained-the chest and abdominal
cavity For the artcuates, on the contrary 10 Whlch
all Insects crustacea and belong the nervous
system is scattered along the length OF the body
Succession Of swengs connected together by threads
The first these swenes situated in the head above
tho aimentary canal the rest are at regular distances
along lower side OF the body Thus it appears that
the battery from which all y0tiOn starts, by Whlch
ali the acts OF life are performed regulated through
which all external impressions are communicated and
acted upon very different in these two types of the
animal kingdom. 1t is therefore hardly probable that
the life done by these shond be the same


swARMISG AND THE EXIT OF THE QUEEN BEE


Let US look at some Of the by which the quality
we call instinct is manifested in community OF bees
When such a community becomes too POpuous for
gwen hive the bees swarm" 1t is called that is
part OF the Oyercrowded population separates from the
rest and goe5 off TO establish colony. In such
case the emigrants chosen form their band
with direct reference seemingly to the future welfare
OF the new colony, preserving the numerical proportions
Characteristic Of all prosperous hives The swarm con-
queen, thousands of working bees or
uudeveoped females, hundreds Of males or drones
This is the normal combination in the bee community,
and OrQaDiZe1 survive and keep
together many years There reports Of beehves


century old This is, however, probably an exaggera
tOn beehves years Old rare and they do not
often survive more than seven, eight or perhaps ten
years. When speak Of the life Of q beehive do not
to say that the individuals composing 1t live
together for length of tme indeed queen rarely
lives beyond three four years. OF seven years is
seldom seen while the males never survive the Summer
IN which they are born, and the working bees die
gradually and replaced by ones. But the hive
a community holds together for much longer period,
being constantly renewed by the process of reproduc-
tOn and comes last like human settlement to
sst of variety Of individuals born at different times
When swarm breaks OFF from old community TO
colony, the division is generally due 10 the
appearance Of new queen The queen bee, usually
quite coneqcd with her lot watching over her progeny
active patient the OF her becomes ur
If rival arises in the bye. She pounces upon her.
aud they sometimes tight TO tho death. SO well is this
understood the hive that the workers take care to
prevent such conflicts by holding back the new queen
Just ready Matched from her royal cell till the bees
have swarmed At such time the workers will stand by
the CELL out Of which queen is to be born, ascertain
how her transformation is completed, and should
there be disposition Of the young queen shortly to
creep out, they increase the deposit of upon the
lid which shuts CELL thus preventing the egress of
the royal prisoner. II she tries TO break through or
attempts to gnaw her way out, the workers crowd
around the opening or accumulate such amount OF
wax upon 1t to rustrato all her efforts When the old
queen peacefully departed the one Is set Free
makes this fact extraordinary is that usually
the workers have never the birth Of queen or
perfect female before their hive has known but one
queen and yet they anticipate and guard against all the
dangers likely arise from second. Can 1t be that
these creatures do the right thing right time
sciousy by OF any faculty similar to our reason