ON

A TRUE PARTHENOGENESIS

IN MOTHS AND BEES;

A CONTRIBUTION TO

THE HISTORY OF REPRODUCTION IN ANIMALS.

BY

CARL THEODOR ERNST VON SIEBOLD,

Professor of Zoology and Comparative Anatomy in the University of Munich, Knight
of the Order of Maximilian, Director of the Zoological and Zootomical
Cabinet, and Conservator of the Zoological Institute in Munich.

TRANSLATED BY
WILLIAM S. DALLAS, F.L.S. &c.

LONDON:
JOHN VAN VOORST, PATERNOSTER ROW.

MDCCCLVII.

Non seniel quardam sacra traduutur ! Eleadn servat quod ostendat revisentibos.
Renim natura sacra sua non simul tradit, Lniriatos nos credimus : in vestibulo ejus
haeremus. IUa arcana non promiscue nec omnibus patent: reducta et in interiore
sacrario clausa sunt. Ex quibus a]iud hare anas, aliud, quae post nos subibit,
dispiciet. — Seneca {Xatural Qu&ttion. lib. viL 31 .

I 0 50 Of

scienxts

QH

SSI

PREFACE.

Engaged in constant efforts to trace and clear up the history
of animal reproduction, as far as this is permitted to human
discernment, I have been guided to a phenomenon in Insect-
life which had for a long time remained obscure to me, — I refer
to the power of reproduction of some female Insects which
remain unfecundated, as this not only appeared to be a great
mystery, but even a fact never yet firmly established, and
therefore still doubtful. I always found this so-called Lucina
sine concubitu treated by physiologists as a sort of curiosity ;
the same examples from Insect-life, derived from the older ob-
servers, were constantly referred to as vouchers. The question,
whether the fact referred to was supported upon a firm basis,
remained at the same time altogether unnoticed. As every kind
of statement with regard to Lucina sine concubitu was received
with so little caution and without suspicion, new observations
were added to the older defective notices of this kind ; but these,
in the same way, appeared inadmissible as soon as they were
carefully analysed.

Since the process of the fecundation of the egg has become
much better understood by the recent discoveries of Newport,
Keber, Bischoff, Leuckart, Meissner, and Bruch, one was com-
pelled to say, that all the cases of Lucina sine concubitu observed
in former or modern days might be founded upon delusion
or error, because up to this time the knowledge of the con-
ditions under which fecundation takes place was still extremely
imperfect. Now, when the physiology of reproduction has
been enriched with many exceedingly important discoveries,
and by these some essential points in the act of fecundation,

iv

PREFACE.

which had been previously overlooked, have been brought to
light, very different claims are made upon those observations,
by which it is to be decided, whether an egg which has arrived
at development was or was not fecundated.

For this reason I was not to be blamed if I made my first ap-
pearance as a sceptic, and submitted this subject to an exami-
nation corresponding with the present fundamental laws of
Physiology. The results of this examination, contrary to ex-
pectation, have furnished the proof 1. that a Lucina sine con-
cubitu does exist ; and 2. that this does not merely start up here
and there accidentally, as was formerly supposed, but that it
occupies its perfectly definite position in nature. It is true that
it still remains concealed from us, according to what laws and
under what motives this remarkable mode of reproduction has
obtained the place assigned to it in the history of reproduction.

In these investigations, to which I have devoted the careful
study of many years, I was very readily and disinterestedly
assisted by various naturalists, who, partly by providing me with
the materials necessary for such investigations and observations,
but partly also by communicating their own multifarious expe-
rience upon the department in question, put me in a position to
obtain as wide a glance as possible over this still imperfectly
explored field. I therefore regard it as my duty to express my
public thanks here to Baron von Berlepsch of Seebach, MM.
Bremi of Zurich, Dzierzon of Carlsmarkt, Professor F. de
Filippi of Turin, Dr. Herrich-SchafFer of Ratisbon, Senator von
Heyden of Frankfort a. M., M. Kollar, Director of the Imperial
Cabinet at Vienna, MM. Radlkofer of Munich, Reutti of Frei-
burg, Dr. Rosenhauer of Erlangen, A. Schmid of Eichstadt,
Steiner of Breslau, and Professor Zeller of Glogau, for the
assistance which they rendered me in my investigations.

C. T. E. VON SlEBOLD.

Munich, 25th March 1856.

TRANSLATOR'S PREFACE.

Of all the discoveries which have been made of late years in
the history of the reproduction of animals, none is of greater im-
portance than that of the entrance of the spermatozoids into the
ovum, which is found to be the rule not only in the Animal, but
also in the Vegetable Kingdom. Nevertheless, but a few years
have elapsed since the final settlement of this disputed question,
and we have in the following observations of Professor Siebold
a clear proof of the occurrence of phasnomena, which, if they do
not invalidate the law, at least show that it is liable to some,
probably to many exceptions.

Several years ago our author published some observations
upon a species of Psyche, which, as he stated, propagated without
copulation. He referred this singular occurrence to the same
class of phaenomena as the asexual reproduction of the Aphides,
the so-called Alternation of Generations ; and although it must
have been evident to every one who attentively studied his paper
that the circumstances of the two cases were widely different, it
was impossible, in the state of our knowledge at the time, to
propose any more satisfactory explanation of the phenomenon.
Now, however, the whole face of affairs is changed. Von
Siebold, as will be seen in the following pages, has clearly
proved the existence of a sexual reproduction without fecunda-
tion, not only in the Psychidce, to which his former observations
related, but also in the Bees, — in both as a regular occurrence,
and as an occasional phenomenon also in the Silk-worm Moth ;
the latter circumstance giving a considerable degree of proba-
bility to some even of those supposed cases which our author dis-
cusses and rejects as inadmissible in the first section of his book.
For this phenomenon of reproduction by virgin females the
author adopts the term Parthenogenesis, originally proposed by

VI

translator's preface.

Professor Owen to express the dissimilar Digenesis or Alternation
of Generations.

That the same thing occurs in other species of animals
besides those upon which the author's observations have been
made, there can be no doubt, and. in fact, several of these are
indicated in his concluding remarks. Of some of the Ento-
mostracous Crustacea no males have vet been detected, whilst
the females of others have been observed to propagate without
concourse with the male. A still more striking instance is
afforded by the Gall-flies belonging to the restricted genus
Cyuips. of which several species are very common in Europe,
and yet amongst the thousands which have been reared from
galls, not a single male has ever been seen. An oak-gall has
been found in great quantities of late in Devonshire, which has
attracted considerable attention from those few Entomologists
in this country who trouble themselves with the study of
Hvmenoptera. ' It is produced by a species of Cynips, and all
the specimens, to the number of several hundreds, which have
been reared, connrm the above statement as to the absence of
males. Some experiments now being made by Mr. Smith of
the British Museum, whose tact and power of observation so

pro y o «- *- —

cited in support of the interesting and important theory
developed by Von Siebold in the following pages. Amongst
the Entozoa, we may also probably meet with further instances
of Parthenogenesis, as their propagation, notwithstanding the
great advances that have of late been made in our knowledge
of its phenomena, still presents much that is enigmatical.

But it is not only in the Animal Kingdom that we meet with
this phs-nomenon of ovular reproduction without impregnation :
similar instances occur also amongst the Phanerogamous plants.
Many years ago, Camerarius and Spallanzani asserted that the
female Hemp was capable of producing fertile seed without the
aid of the male pollen ; and a French botanist, M. Lecoq, has
lately addressed a note to the Academy of Sciences, referring to
some experiments made by him, and published in 1S27, upon
the same subject. His experiments were made upon various
dioecious plants, amongst which Hemp, Spinach, Mercurialis

translator's preface.

vii

annua, and Trinia vulgaris furnished him with fertile seeds,
although every precaution was taken to isolate the plants. (See
Comptes Rendus, 8th December, 1856, p. 1069.) A dioecious
Euphorbiaceous plant also, the Ccelebogyne, from Australia, has
produced fertile seeds in the Botanic Gardens at Kew, although
only the female is known to botanists.

Interesting as this curious discovery of Von Siebold's must
be to the Physiologist, there are some points connected with it
which render it of the highest practical importance to the
keepers of Bees. The greater part of the following pages is
devoted to the consideration of the wonderful series of phe-
nomena presented by the reproduction of those industrious
Insects, and the intelligent Bee-keeper will find that by studying
it he will obtain many hints, which, if properly applied in prac-
tice, may enable him not merely to study the habits of his in-
teresting charges with much greater satisfaction than heretofore,
but also, by proper management, to increase the profits derivable
from his hives, — a consideration which may perhaps have more
weight with many than any of a purely theoretical nature.

Although I cannot flatter myself that I have done full justice
to the exceedingly happy phraseology in which Professor von
Siebold has communicated his results to the world, I have
endeavoured as far as lay in my power to adhere strictly to the
original, so that the English reader might at least be sure of
getting the true sense of the author.

The proof-sheets have been submitted to Professor Owen, who
has kindly enriched them with some valuable notes, of which
those relating to Hunter's views are especially interesting. The
additional notes are all included between brackets.

W. S. DALLAS.

London, 20th January, 1857.

CONTENTS.

Page

Introduction 1

Elucidation of the Cases hitherto described as Parthenogenesis . . 12

True Parthenogenesis in some Sac-bearing Lepidoptera 24

True Parthenogenesis in the Honey-Bee 38

True Parthenogenesis in the Silk-worm Moth 92

Concluding Remarks 104

Explanation of the Figures 109

ON

TRUE PARTHENOGENESIS.

INTRODUCTION.

It is high time that Zoologists and Physiologists should turn
their attention to a phenomenon in the history of the re-
production of animals, which, during the last few years, has
warmly interested the Apiarians and set them in the greatest
excitement, — I mean the mode in which each separate colony of
Bees contrives that the worker-, drone-, and royal-cells prepared
by it are always furnished with the proper eggs, from which, as
is required by the arrangement of these different kinds of cells, the
worker-larvae, drone-larvae, and queen-larvae destined to dwell in
them, are always excluded. Hence the oviposition in the Bee-hive
must be effected according to peculiar rules, in order that the
conditions just mentioned may be fulfilled; this act of oviposition
must be subjected to determinate laws, which do not affect the ovi-
position of most other insects, as in these it is a matter of indif-
ference in what consecutive order and number male and female
eggs are laid. But the question, how each separate Bee-colony
succeeds in obtaining the suitable supply of eggs for all its combs,
differently as these are prepared as regards the number and
arrangement of the three kinds of cells, has not been easily
answered ; nay,we may perhaps say, that this process has hitherto
appeared to be an impenetrable mystery, the solution of which
has not been effected by the most careful endeavours and observa-
tions of the x\piarians continued for many years. This mysterious

B

2

INTRODUCTION.

circumstance, which distinguishes the oviposition of the Bees, has
also been the cause that, from time immemorial, the Apiarians have
been disputing about the signification of almost every individual
step in the process of reproduction in the Bees. This contest
has continued even to the present day, and it is scarcely possible
to imagine a single absurdity with regard to the history of the
reproduction of the Bees, which has not already been expressed
in sober earnest by some Apiarian, and is not to be read in print
in one of the innumerable Bee-books. The greatest confusion
especially was caused by the circumstance, that people could
not agree with regard to the sexes of the Bees ; the Drones
were regarded as females and the Queens as males ; sometimes
it was supposed that the Workers alone had the care of the
oviposition ; sometimes the true act of copulation between the
drones and the queen was supposed only to take place in the
interior of the hive ; the wedding-flight of the queen would then
only be a sort of purification ; whilst from another side it was
asserted that the act of copulation was never performed in the
hive, but always high up in the air during the wedding-flight.
The act of coition was also entirely denied, the queen becoming
fertilized by the mere agitation of her body during the wedding-
flight. I could fill many pages here with these contradictions,
which are deposited in the annals of the history of Bee-life, and
by which the study of this otherwise so interesting subject from
books, has been stunted into a most ungrateful task.

This endless dispute about the reproduction of the Bees,
often carried on with great animosity, in which the opponents of
the different theories of generation relating to the Bees often
showed themselves to be mere dilettanti, miserably furnished
with natural-history information, was not fitted to attract the
interest of physiologists ; indeed, it appeared as if the Apiarians
wished to fight the battle out amongst themselves without
foreign assistance, for the contest was never brought within
the province of an earnest investigation of nature. Moreover,
the naturalists could not very easily take part in the dispute,
as they were mostly deficient in the practical knowledge of
the oeconomy of Bees, without which every attempt to settle
the matter must have turned out imperfect, and would have
been received with distrust by the obstinate Bee-masters, to

INTRODUCTION.

3

whom such an attempt might have served as an instructive
hint. In this dispute of the Apiarians, which was constantly
blazing up afresh, the activity of the naturalists limited itself
to their ascertaining and establishing as an incontestable truth,
by the aid of the dissecting-knife and the microscope, that the
drones are the male individuals, that the queen is the female
individual, and that the workers are not merely asexual, but
female individuals, the reproductive organs of which had not
come to their full development. Upon this subject, investiga-
tions were made and published by the zootomists at very dif-
ferent periods. I refer only to the works of Swammerdam*,
Reaumurf, Mademoiselle JurineJ, Suckow§, and Ratzeburg||.
Although the representations of the male and female sexual
organs of the Bees have been copied from Swammerdam's Biblia
Naturae by various writers upon these insects, and consequently
the facts established anatomically were communicated to the Api-
arians, yet for a long time these truths could not boast of a re-
cognition by all Bee-keepers. These entomotomic investigations
probably did not appear sufficiently significant to the Apiarians,
because there were still many things in the history of the re-
production of the Bees, which could not be explained with this
knowledge of the sexual relations of these animals. Many
practical Apiarians looked upon this anatomical proof of the
sexes of Bees merely as theoretical stuff, and returned to their
so-called practical way, which they imagined to be the right one,
without regard to these facts, preferring to explain the different

* Bibel der Natur, 1752, pp. 188 & 202, taf. 19 & 21.

t Memoires pour servir a VHistoire des Insectes, tome v. 1741, pi. 32-34,
which portion appeared in 1759 translated into German under the title of
" Geschichte der Bienen."

% Vide Huber, Nouvelles observations sur les Abeilles, 2de edit. 1814, p. 431 .
pi. 11. fig. 1 . In this work are deposited the interesting anatomical investiga-
tions of the above-mentioned lady, by whom the existence of abortive ovaries
in the Worker-Bees was first ascertained ; they are represented in an admirable
figure prepared by herself.

§ Heusinger's Zeitschrift fur Organische Physik, Band ii. Heft 3, 1828,
p. 231. taf. 12. fig. 30, taf. 14. fig. 38.

|| Brandt und Ratzeburg, Medizin. Zoologie, 1833, p. 202. taf. 25. figs. 34,35,
as well as Ratzeburg's Untersucliung des Geschlechtszustandes bei den soge-
nanntenNeutris der Bienen unduber die Verwandtschaft derselbenmit denKbnig-
innen, 1833, in the Nova Acta Physico-Medica, vol. xvi. pt. ii. p. 613. tab. 4/.

B 2

4

INTRODUCTION.

sexual functions in a perfectly arbitrary and unnatural fashion,
according to their own individual and often very limited views.

After I had, in the year 1 S 3 7 - ascertained the existence and
signification of the seminal receptacle in female insects*, and in
1S43 called attention to this reservoir of semen in the Queen-
Bees t, by the functions of which many phaenomena in the repro-
ductive activity of the Bees, which had hitherto remained pro-
blematical, or had been incorrectly explained, might be properly
conceived, these investigations exerted no particular influence
upon the perverted views of most of the Apiarians. They pro-
bably paid no further attention to them, as theoretical stuff, and
yet, by the recognition of the function of the seminal receptacle, a
phenomenon in the Bee -hive, which had been a source of wonder
from time immemorial, could now be correctly explained. Thus,
it had been ascertained by me, that after copulation had taken
place, the semen of the drone, which filled the seminal receptacle
to overflowing, remained in this place, capable of impregnating
the eggs, not merely for months, but for years, as might be seen
from the movements of the spermatozoids of this semen con-
tinuing for that period!. This explains how a queen, fertilized
by a single coitus, after discharging her eggs in the first year,
may again, in the following year, and even still more frequently,
lay eggs capable of development, such as the hive requires, as
fertilizing semen is still constantly preserved in her seminal re-
ceptacle, to fecundate eggs even for so long a period. But even
this discovery was ignored by most of the Apiarians ; as a general
rule, fresh scruples as to the value of such anatomical and micro-
scopical investigations were constantly rising amongst them, with
respect to the determination of the sexual functions of the Bees.

There were two phaenomena especially in the oeconomy of the
Bees, which troubled the minds of the Apiarians with reference
to the division of the sexual functions in those insects, — I
mean, 1. the capability of an imperfect-winged female to pro-
duce brood, and 2. the production of brood in a queenless

* See iny Observations upon the Spermatozoa in fecundated female Insects,
in Mutters Archie, 1537.. p. 417-

t Ueler des Receptacuhm seminis der Hymenopteren- TVeibchen, in Germars
Zeitschrift fur dit Entomologie. Bd. iv. 1543, p. 371.

* See Germar's Zeitschr. Joe. cit. p. 374 with regard to Apis mellijica),
and Wiegmann's Archiv, 1539. i. p. 107 [Vespa rufa).

INTRODUCTION.

5

hive. Those who acknowledged the Queen as the female indi-
vidual of the Bees, and, in accordance with the physiological
laws hitherto current, ascribed to her the property of laying
eggs capable of development only after previous copulation and
the filling of the seminal receptacle with spermatozoids, were,
in consequence of the first-mentioned phenomenon, rendered
doubtful where and when the copulation of the Queen-Bee is
effected. From this arose the dispute, so abundantly battled
out in the books and journals relating to Bees^ as to whether
the Queen copulates in or out of the hive. That the former was
possible was thought to be proved by the imperfect-winged
Queens laving eggs capable of development, and thus the two
sexes of Bees were supposed to perform the act of copulation in
the interior of the Bee-hive, although such a copulation in the
hive had never been seen. In this respect the Bees shared the
same fate with the Roes ; in these animals the practical game-
keeper could not comprehend why, after the single rutting time
(in August and September), the uterus of the Roe contained
no embryo, and therefore incorrectly ascribed a second rutting
time (in December) to the Roes, although no one had met with
Roes in copulation during that period. In those cases in which
the second remarkable phenomenon previously mentioned oc-
curred, namely, brood in a queenless Bee-hive, we should entirely
mistake the sexual functions of the Bees. Such observations
were principally employed in raising objections of insufficiency
and untenability against the scientific endeavours at the determi-
nation of the sexes of Bees.

In most Zoological or Entomological works we find all these
acrimonious controversies regarding Bee-life, either imperfectly
mentioned or scarcely indicated, and hence it may have hap-
pened, that the history of the reproduction of the Bees has
remained untouched by those physiologists who have specially
occupied themselves with the generation of animals*. On this
side no one had any idea what difficult problems are here pre-
sented to science for solution. Moreover the physiologists were
lately engaged by another very attractive but also very difficult

* In the ample article upon Propagation (Zeugung) by R. Leuckart (see
R. Wagner's Handicorterbuch der PhysioJogie, Bel. iv. 1853), the remarkable
history of reproduction in the Bees is scarcely touched.

6

INTRODUCTION.

subject, which incited them to inquire after the laws, according
to which the asexual reproduction, previously regarded as an
exception and now characterized by the name of Alternation of
Generation, occurs disseminated amongst the lower animals,
together with sexual generation.

By the entomologists the physiology of reproduction has been
very scantily enriched of late, as most of them found their task
only in rectifying the species of Insects ; many of them endea-
voured, at the expense of much time and trouble, to determine
those species which have been furnished with names by Linnaeus
and Fabricius, whilst the majority found a still greater pleasure
in enriching the systematic catalogues of Insects with a few
perfectly new, although extremely insignificant species.

As up to a very recent period the Apiarians formed a sort
of close corporation, wishing to answer the most important
questions relating to the reproduction of the Bees amongst
themselves, it may thus have happened that the fruits with
which the knowledge of the history of reproduction was enriched
by the labours of modern naturalists, could not be perceived at
all by this close and short-sighted circle, and consequently could
not be made use of by them. Nor did any voice ever force its
way out of their circle which might have called in the assistance
of the physiologists in the decision of certain problems in the re-
production of the Bees. Only within the last three years has the
demeanour of the Apiarians changed in a most satisfactory way,
and it must be said, in praise of the present circle of Apiarians,
that at this moment it numbers amongst its members, men who
have arrived at a conviction that Bee-life does not merely serve
to furnish man with wax, honey and mead, but that it consti-
tutes an extremely remarkable link in the great and most multi-
fariously composed chain cf animal existence, the importance of
which, however, can only be understood by the assistance of
knowledge such as is furnished by the present development of
the Natural Sciences. By the activity of these enlightened men
a complete revolution has taken place in Bee-keeping; a rational
process introduced by the Apiarians, and rewarded by the richest
results, now celebrates the most complete triumph over empiri-
cism, and in this the names of Dzierzon and Berlepsch above
all deserve to be named as conquerors.

INTRODUCTION.

7

I believe I ought to give some information as to the way in
which I have been induced to take part in this active movemeut
of the Apiarians, as reference is made hereafter to a new theory
of reproduction applying to the Bees, the defence of which I
have undertaken, not however from a preconceived opinion forced
upon me from without, but from an internal conviction springing
from the course of my own investigations and observations.
From the following pages the reader will understand how the
investigation of the history of reproduction in Insects necessarily
led me to the natural history of the Bees.

Probably within the last few years no branch of the history
of animals has been enriched by new discoveries, and the am-
plification and completion of old observations, in so high a
degree as the theory of animal reproduction. A mass of facts
which were in direct contradiction to the theoretical laws so
long established as the rules for the propagation of animals, and
which previously had scarcely any value but their curiosity,
have been united by the piercing eye of Steenstrup under the
name of Alternation of Generations* to form a law, which is
now found by naturalists to prevail in all directions. There was
previously a long series of remarkable observations, against the
correctness of which, as they stood in contradiction to the laws
of reproduction previously adopted as the rule, doubts might
willingly have been raised, if the stamp of truth had not been
impressed upon them by the credibility of their observers.
From many of these observations, over which a naturalist here
and there was every now and then shaking his head in in cre-
dulity t? all doubt has been now cleared away by the recognition

* Steenstrup, Ueber den Generationswechsel, Copenhagen, 1842.

f This negation of the processes connected with the alternation of genera-
tions is expressed even in the most recent times, in the views by which Ehren-
berg and Diesing explain the nature of the Cercaria. Although direct
observations and the most careful investigations have shown that these re-
markable asexual creatures are not perfect animals, but belong, as larvae, in
the developmental series of certain Trematode worms, Ehrenberg sticks stead-
fastly to his opinion, that the Cercarice only present a distant similarity to
the Trematoda (see the Bericht iiber die zur Bekanntnwchung geeigneten Ver-
handlungen der Akad. der IViss. zu Berlin a. d. J. 1851, p. 776), and re-
proaches Steenstrup with having allowed himself to be misled into the

8

INTRODUCTION.

of the alternation of generations. Other observations which
still remain problematical, the results of which also will not
accord with the fundamental laws of the history of reproduction
as at present known, will probably, as we must hope, be here-
after lighted up by the rays of the alternation of generations.
Nevertheless from my own investigations I have also come to
the conviction, that on the other hand we must not expect too
much from the alternation of generations, as when we wish and
imagine it, we do not always obtain an explanation from it. I
must give especial warning against following an investigation
too far with the preconceived notion that we have to do with an
alternation of generations, as otherwise we may be led widely
astray upon a false course, and never find the right way.

Not to deviate too far from the object which I have set before
me in these pages, I will only here give prominence to that in
the history of Insects which people have been induced to regard
as a peculiarity of the alternation of generations, — I mean the
remarkable reproduction of the Aphides ; this, after standing so
long as something quite abnormal and inexplicable, has now
found its complete explanation in the nature of the alternation
of generations. It is well known that in the Aphides, a sexual
generation, represented by separate males and females, is followed
by a series of generations, only including a single form, which
proceed from each other in manifold repetition without any pre-
vious copulation, until after about seven to eleven such genera-
tions, a generation of males and females again makes its appear-
ance. Steenstrup* regarded these forms of Aphides, which are
capable of reproduction without the influence of the male gene-

important error of supposing that the Cercaria; became developed into
Distoma by casting off their tails. Ehrenberg at the same time refers to his
exposition, description and figure of the Cercaria Ephemera, given in the year
1828 (Symbola; Physical, Phytozoa Entozoa), which to his regret has not
been referred to by Steenstrup, and which would probably have preserved him
from some errors. In this description, however, Ehrenberg has declared the
excretory organ representing a primordial kidney to be ovaries, and its coarsely
granular contents, eggs, to which I have long since called attention (see my
Lehrbuch der vergleichenden Anatomie der Wirbellosen, p. 139). Diesing, no
less consistently, holds fast by the belief that the Cercaria; are an independent
and closed group of animals (see his Revision der Cercarien, in the number for
March 1855 of the Sitzungsberichte der Akad. der H iss, in lYien).
* Op. cit. supra, p. 121.

INTRODUCTION. 9

rative organs, and which had previously been looked upon as
virgin female Aphides, as Nurses {Ammen), and consequently as
those members of an animal-species subjected to an alternation
of generations, which are capable of producing young in the
asexual (or larval) state. Those Aphides which bring forth living
young without a preliminary copulation, are in reality quite dif-
ferent in their organization from the true female Aphides, which
lay eggs capable of development after the act of copulation. In
the viviparous Aphides those organs especially from which the
living young are produced, have quite a different form and organi-
zation from the sexual organs of the oviparous female Aphides,
so that, in opposition to the ovaries (Eierstocke), the products of
which (eggs) only become capable of development by the action
of the male semen, we may with perfect justice indicate these
organs as germ- stocks (Keimstoeke), which are capable of pro-
ducing young of themselves, without the influence of male fer-
tilizing organs. These nurse-like, viviparous Aphides therefore,
which instead of ovaries bear germ- stocks in their interior, are
also destitute of the seminal receptacle, which occurs universally
in the females of Insects and plays an important part in the act
of fecundating the eggs*. Before the alternation of generations
had yet been introduced into science by Steenstrup, I had al-
ready called attention to the different conditions of organization
in the oviparous and viviparous Aphides, and especially to the
absence of the seminal receptacle in the latter f. Subsequently
the development of the Aphides without fecundation has been
completely explained by V. Cams J as a process of the alterna-
tion of generations. The representation which Cams has given
of the development of germinal bodies in the germ-stocks of the
viviparous Aphides, has certainly met with a refutation from
Leydig§, against which I have nothing to object; nevertheless,
although, according to Leydig, the young are developed from
the germ-bodies of the viviparous Aphides exactly as from eggs,
by cell- formation, I would retain the denominations "germ-

* See my Observations on the Spermatozoa in fertilized female Insects.
Muller's Archiv, 1837, p. 392.

t See Froriep's Neue Notizen, Bd. xii. 1839, p. 308.

X Zur ndheren Kenntniss des Generationswechsels, 18-J9, p. 20.

§ Bemerkungen iiber die Entwickelung der Blattlause in Siebold and Kblli-
ker's Zeitschrift fur mssenschaftliche Zoologie, 1850, p. 62.

10 INTRODUCTION.

body " and " germ-stock M for these reproductive organs of the
viviparous Aphides, in order to distinguish them, on account of
their different physiological import, with regard to the alterna-
tion of generations, from the eggs and ovaries of the oviparous
female Aphides.

Owen* has regarded the asexual viviparous Aphides as virgin
females capable of reproduction ; but these viviparous Aphides
indicated by Owen as virgin parents are certainly something
very different from the oviparous Aphides in their virgin state
before copulation. For the same reason also I cannot approve
of Owen's expression Parthenogenesis, as applied by him to the
alternation of generations, as under the term Parthenogenesis I
do not understand reproduction by asexual nurse-like or larval
creatures, but a reproduction by actual females, that is to say,
by individuals furnished with perfectly developed, virgin female
organs, which produce eggs capable of development without pre-
vious copulation and in an unfecundated condition.

* On Parthenogenesis, or the successive production of procreating indivi-
duals from a single ovum. London, 1849, pp. 30, 60, & /6.

[By reference to this work, it will be seen that, in the description of the
parthenogenesis of the Aphides, the viviparous individuals are called i larvae,'
and the basis or blastema of the virgin-progeny 'germ-masses' : both are ex-
pressly distinguished from the true ova and oviparous females.

w The facts are briefly these : —

" The impregnated ova of the Aphis are deposited at the close of summer,
in the axils of the leaves either of the plant infested by the species or of some
neighbouring plant, and the ova, retaining their latent life through the winter,
are hatched by the returning warmth of spring : a wingless hexapod larva is
the result of the development. This larva, if circumstances, such as warmth
and food, be favourable, will produce a brood, and indeed a succession of
broods of eight larvce, like itself, without any connection with the male. In
fact, no winged males at this season have appeared. If the virgin progeny
be also kept from any access to the male, each will again produce a brood of
the same number of Aphides ; and carefully prosecuted experiments have
shown that this procreation from a virgin mother will continue to the seventh,
the ninth, or the eleventh generation, before the spermatic virtue of the
ancestral coitus has been exhausted. When it is so exhausted, a greater
proportion of the nuclear germ-masses retained by the last procreant larvae is
used up : individual growth and development proceed further than in the
parent : some members of the last larval brood are metamorphosed into winged
males, others into oviparous females. By these the ova are developed, im-
pregnated, and oviposited." — Owen's 1 Parthenogenesis,' p. 23.]

INTRODUCTION.

11

This last mode of reproduction has been denominated Lucina
sine concubitu by the older naturalists, a term, which must not
be applied, as has been done by Owen, to the alternation of
generations, the reproduction taking place in this case under
totally different conditions, namely by division, by gemmation,
or by germ-bodies, which are not to be confounded with eggs, as
in all these modes of propagation the immediate influence of the
male fertilizing elements is wanting, and this has not been acci-
dentally or abnormally omitted, but, as is proved by the whole
course of development of these generations, remains out of action
in accordance with certain laws.

As, with reference to my subsequent statements, I must lay
a particular stress upon the distinction between the Alternation
of Generations and Parthenogenesis, I repeat once more, that the
viviparous Aphides are not virgin females which produce eggs
capable of development without copulation, but that they are
asexual, nurse-like or larval individuals, furnished with germ-
stocks, which are as different as possible from the true virgin
female Aphides*.

* [The author of the term ' parthenogenesis/ which was devised to replace
a phrase both cumbrous and incorrect, or at best only partially agreeing with
the phenomena referred to in the text, believed it to be, etymologically, appli-
cable to the male as well as the female, or the neuter. 6 napdevos is ' a young
unmarried man,' just as f) <nap6evos is 'a maid': napdeveia, * virginity, purity,'
is predicable of either sex, or of a generative individual of no sex. The term
' parthenogenesis ' was by no means proposed, as Siebold seems to imagine,
under the idea that the virgin procreative Aphis was a perfect female, and its
brood produced from eggs. Previously to the appearance of the book so
entitled, Professor Owen had published the results of observations showing
that the virgin Aphides developed their brood from nucleated cells, forming
' germ- masses,' not from eggs (Lectures on Invertebrata, 1843); and the
difference between the larviparous virgin and the oviparous wife in the Aphis
tribe is given in detail. He defines 'parthenogenesis' to mean 'procreation,
without the immediate influence of the male,' as, e. g., spontaneous fission,
gemmation, development from germ -cells and germ-masses, or from unim-
pregnated ova. Should physiologists prefer, however, to limit the term as
proposed by Professor Siebold, they will probably concur in the desirability of
some other single word as an equivalent to ' Alternation of Generations.' By
e metagenesis ' is meant the sum of those changes which certain species undergo
in the progress, through successive individuals, from the ovum to the perfect
impregnating and egg-producing form.]

12

ELUCIDATION OF THE CASES HITHERTO DESCRIBED AS
PARTHENOGENESIS.

Since the remarkable reproductive history of the Aphides
must be transferred into the domain of the Alternation of Gene-
rations, it becomes a question whether we are not acquainted
with other facts in the history of Insects, which are to be re-
garded as Lucina sine concubitu or Parthenogenesis. In point of
fact, observations have been published by the most different
Entomologists of old and modern times, which should lead us to
infer the pretty widely diffused existence of a true Partheno-
genesis amongst Insects. But all these narratives of female
Bombyces and other moths, which, when kept isolated and with-
out any copulation, laid eggs from which young were afterwards
excluded, require a more exact ins estigation ; for before we
allow an important physiological law, derived from multifarious
observations, to be thrown down by such statements, it is ne-
cessary to determine, whether we can put implicit faith in
these narratives, whether we have to do here with credible facts,
or whether, in this case, a fact has not been rather concluded
from superficial, unsatisfactory and scanty observations, than
positively proved. I have already indicated these cases*, as
being such as to require an exact investigation, to get rid of every
doubt as to the assertion that a spontaneous evolution of brood
can really take place in the eggs laid by virgin female insects.
I had at that time proposed to myself to submit the cases brought
forward by so many naturalists and narrated again and again, by
which the existence of a Lucina sine concubitu was to be proved,
to a careful criticism. This criticism I will now undertake, in
order to show how little of all these assertions remains admis-
sible : for as we have to do with the maintenance or abolition of
a physiological theoretical law, the importance of which has long
been recognized, it follows as a matter of course, that none but

* See Zeitschrift ftir icissenschaftliche ZoologU, 1S49, p. 97.

SUPPOSED CASES OF PARTHENOGENESIS.

13

perfectly credible observations and such as exclude all doubt can
be admitted as of sufficient weight to abolish the law : — that true
eggs (produced in an ovary) cannot become developed into an
embryo, until they have first been exposed to the fertilizing in-
fluence of the male semen (produced in testes).

The oldest communication relative to the reproduction of fe-
male insects sine concubitu, and one which has been repeatedly
quoted, is due to the surgeon J. P. Albrecht of Hildesheim, who,
in the year l?0l, sent in to the Leopoldine Academy of Natu-
ralists, a memoir with the title* u De Insectorum ovis sine praevia
maris cum fcemella conjunctione nihilominus nonnunquam fce-
cundis." In this memoir Albrecht relates that he took a brown
pupa, which had spun itself up on a black-currant bush, and pre-
served it under a glass in his summer-house, to see what moth
would be evolved from it. At the end of July a moth of a yellow-
ish-white colour escaped from it ; this is not more particularly
described, but as Albrecht has compared it with the Moth figured
by Godart in his Metamorphosis et Historia Insectorum (Pars I.)
on tab. 33, we may suppose that it was either a Bombyx or a
Noctua. This moth in a few days laid a great number of eggs
and then died. Upon this Albrecht has the following remark : —
"Cum masculum huic papilioni haud adfuisse certus essem et
propterea ejus ova subventanea et sterilia esse judicarem, vix
amplius eorum habui rationem, relictis interim iisdem oscitantius
et sine omni cura sub dicto vitro per totum tempus hyemale."
It was only in April of the following year that Albrecht again
looked after the glass, and was astonished at finding young black
caterpillars in it instead of the eggs. As Albrecht has given no
exact description, either of the nature of the glass, or of the mode
in which it was closed, and did not watch either the glass or its
contents with the necessary care, it does not appear from this
case, whether the openings of the glass in which the moth was
kept were closed in such a manner that no male moth of the
same species could have found admittance and an opportunity of
copulating with the enclosed female. The same surgeon also
mentions a Spider, which had been in the possession of Dr.
St. Blancard, and which for four consecutive years laid eggs

* See Miscellanea curiosa sive Ephemeridum Academics Caesar. Leopold.
Natur. Curios. Dec. iii. Annus ix. & x. 1706, p. 26.

14

SUPPOSED CASES OF

from which young Spiders escaped, although no male Spider
had ever appeared in the business*. This short communi-
cation gives us not the smallest information upon the question,
whether this fertile Spider was actually taken in the virgin
state, and whether her seminal receptacle may not have been
filled with semen, before her capture, by a male Spider. Pre-
cisely the same remarks will apply to that female Spider which
Dumeril saw in Audebert's possession f, and which produced
brood for two years when imprisoned, without the assistance of
a male. That the male semen preserved in the seminal recep-
tacle of the female insect retains its fertilizing power for years,
is an ascertained fact; we know, for example, of Queen-Bees,
that after a single copulation they may be fertile for four or five
years ; and upon this point I may appeal to the testimony of
the Pastor of Carlsmarkt in Silesia, M. DzierzonJ, whom I
have learnt to know and value as one of the most experienced
and credible Bee-keepers, amongst living Apiarians. Another
observation of spontaneous reproduction sine concubitu, made
by Basler upon a female of Gastropacha quercifolia bred from
the caterpillar, is very briefly communicated by Bernoulli §.
As in this case we neither find any mention of how long it was
after the exclusion of the moth before Basler found it^ nor
any account of the secure preservation and shutting up of
the pupa, a number of objections may be raised against the
supposed Parthenogenesis in this case, on the ground of the
deficiency of all exact details. No less inadmissible appears
the case observed and communicated by Bernoulli himself as one
of Parthenogenesis |! . He had allowed a caterpillar of Episema
cartdeocephala to change to the pupa state, but afterwards left
the pupa in a box without paying any further attention to it ;
in about fifteen days he opened the box for the first time, and
was surprised to find in it, besides the excluded moth which

* This observation was first communicated in the Miscellanea curiosa, Dec.
iii. Annus iii. 1696, p. 63.

t See Dictionnaire des Sciences Naturelles, torn. ii. 1816, p. 324.

X See his Theorie und Praxis des neuen Bienenfreundes, 2 Aufl. 1849, pp.
104 & 111.

§ See Nouveaux Memoires de V Academie Royale des Sciences et Belles-
Lettres, Annee 1772 Berlin, 1774, pp. 24 & 34.
|| Op. cit. supra, p. 25.

PARTHENOGENESIS.

15

was dead, a family of young caterpillars which had already de-
voured the pupa-case of their mother and a portion of their own
egg-shells. The untenability of the assertion that, in the cases
just mentioned, a Lucina sine concubitu took place, has already
been proved with such convincing reasons by the Theresian
professors [Denis and Schiffermuller), that I cannot do better
than appeal to the arguments which the learned Viennese
entomologists carried out in the following words*: —

"We have too often observed that males have found their
way to females which had been excluded in our rooms, and were
perhaps even stuck upon a pin, and copulated with them, when
we did not at all expect it, and frequently only observed it
accidentally and late, and we have hardly observed this more
with any species than with the very two species of Bombyces
(in our catalogue, Fam. J. No. 1 and B. No. 1 f) which according
to the naturalists above mentioned laid fertile eggs without copu-
lation ; of the latter species indeed, we have frequently exposed
a female designedly in the evening at the open window, in order
to take males, which our friends required, and generally with
the desired result. The narratives even of both the learned men
appear to us not quite to exclude such an unperceived accident,
or an accidental confusion or mistake. Herr Basler did not
imprison the pupa but the excluded female in a glass (certainly
as soon as he observed it), and left the eggs lying uncared for,
upon a stone, until November; moreover he did not rear the young
caterpillars ; and Herr Bernoulli let the pupa with the box go
out of his sight until he found caterpillars already in it. Lastly,
these very two species have often been reared by Reaumur,
Rosel and other naturalists, and in very considerable numbers
by ourselves ; and would they not once have asserted their
power of propagating without copulation, if they really possessed
it? and yet, the females which did not copulate, never laid
anything but barren eggs." Pastor von Scheven also has, with
great tact, weakened the statements of Basler and Bernoulli,
as proofs of the occurrence of a Lucina sine concubitu, by the

* See Systematisches Verzeichniss der Schmetterlinge der Wiener Gegend,
herausgegeben von einigen Lehrern am K. K. Theresianum, 17/6, p. 293.

f The Theresian Professors mean hereby Gastropacha quercifolia and Sa-
turnia pyri.

16 SUPPOSED CASES OF

following objections *: — " Even the most learned naturalist, often
without noticing it himself, comes to the false conclusion : I
have not observed this or that, therefore it has not taken place.
Herr Basler's moth, as the narrative itself shows, was not of
sufficient importance to him for exact observation, until he had
recognized it as a hermaphrodite, by the supposed wonderful
issue. But who is to give us security that a copulation and
fecundation did not previously take place? In all probability Herr
Basler only reared a single moth of this species, from which he
came to the conclusion that no copulation had been possible.
But how easily it may have happened that a copulation never-
theless took place without his knowledge, the following obser-
vations which I had the opportunity of making some years ago
upon the Phal. Quercus, Linn., may distinctly show. Of this moth,
I also had only a single caterpillar, which is figured by Rosel in
the first part of his Insect en- Belustigung en, tab. 35#, and obtained
from it a female moth. But as this came out of its cocoon just
in the evening, I allowed it to creep up to the top of a window
in my room, so that it might expand its wings properly, and as
it behaved quietly, I allowed it to remain there through the
night. The next day I perceived a male of this moth in the
corner of the room, at which I was greatly astonished, as I
knew with certainty that I had not had more than a single
caterpillar of this moth in my house. However, I had not to
wait very long for the solution of the riddle. For soon after-
wards, thinking I heard a tapping at the window several times
repeated, and opening the window to discover the cause of it,
I soon perceived that several moths were flying about before it ;
and although, from their rapid flight, I did not at once recognize
them for what they were, I concluded from their strong flight,
which they occasionally directed straight against the window, that
they had something to seek there. I consequently did not allow
them to knock long in vain, but opened some windows for them,
upon which several males of this moth soon came into my room,
and quickly discovering the female endeavoured to copulate
with her. This history not only shows how strong is the scent of
the male moths of this species and how great is their copulative

* Beitrdge zur Naturgesckichte der Insekten. Naturforscher, Stuck 20,
1784, p. 50.

PARTHENOGENESIS.

17

impulse, but it also leads us to suppose that the same thing-
may have befallen Herr Basler, whose moth belongs to the same
class with ours, and is closely allied to it in its nature and mode
of life. For if the first male which found its way into my room,
and which, no doubt, had slipped in through a small opening in
the window, had immediately copulated with the female, and
afterwards concealed itself in a corner of the room, or flown
away again, and the following day had not been so fine, so as to
give the opportunity for the above observations, I should have
obtained fertilized eggs from my moth, in exactly the same way as
Herr Basler, without thinking that a fecundation had taken place,
and perhaps without thinking an error possible." Bernoulli's
observation also is cleared up by Yon Scheven with such weighty
objections, that every trace of credibility is entirely wiped out of
it. As Scheven has treated the subject with that felicity of
expression peculiar to his time, it would require too much space
if I were to reproduce his polemics in their full extent ; I shall
therefore only quote the most important part of his observations.
Amongst other things in Bernoulli's relation it had struck
Scheven, that in fifteen days after the spinning up of the cater-
pillar the little caterpillars had already escaped from the eggs,
for which reason he expresses himself upon this point as follows*:
" In the ordinary course of nature the caterpillar takes some
days before it becomes converted into a pupa in its cocoon.
The pupa usually lies at least fourteen days, and for the most
part still longer, in its cocoon, before the moth makes its ap-
pearance from it. But still more time is required, before the
young caterpillars come to maturity in their eggs and creep out
of them. The greater or less warmth of the season, or of the
place where the pupae and eggs are kept, certainly often gives
rise to a change in the duration of the time appointed for these
events. But that all these changes should occur within fourteen
days, is just as incredible as that a maiden, who has never seen
a man in her life, and for still greater security has gone into a
nunnery, can give birth to a child there, in an innocent way,
within fourteen weeks. In all probability another female moth,
which the author may have had long previously in this box, and

* hoc. ext. p. 54.

c

18

SUPPOSED CASES OF

which may even have been of a different species (for the observer
does not appear to have carefully examined the young caterpillars,
which indeed are not easily known in their youth), had laid
her eggs in one of the corners of the box, which the possessor
had forgotten, or never observed. From these the young cater-
pillars probably made their appearance, just at the time when
the Phal. pacta* laid her unfertilized eggs; from want of
nourishment they devoured the still fresh and soft eggs, and
finally fell upon the pupa, or rather the pupa-case. This or some
other mistake, of which many may be imagined, may have
happened ; but this much is certain, that the history even in
the way in which it is related and explained, deserves no credit,
and that the conclusions built upon it must be proportionably
incorrect."

I could not refrain from reproducing the objections which
Scheven urged against the observations published by Bernoulli,
literally, as far as space would permit, as they have hitherto re-
mained quite unnoticed; for as often as it was asserted that
certain insects could lay eggs capable of development without
previous impregnation, reference was always made, even in the
most recent times f, to the observations published by Bernoulli,
which however had long before been invalidated as inadmissible
by Scheven.

Just as little value attaches to the other statements which
are supposed to serve as vouchers for the existence of a Lucina
sine concubitu, as, being in the form of very short notices, they
also offer not the slightest security as to what precautions, if any,
were taken to avoid the mistakes which so easily slip into such
observations. For this reason we can attach no weight to the
case which Suckow has communicated without any further

* For what reason Scheven indicates the moth upon which Bernoulli made
his supposed observation upon spontaneous reproduction as Phal. pacta, I do
not know, for Bernoulli compares his moth with the Noctua figured by Rosel
in his Insectenbelustigungen, iv. Sammlung, No. 15, which is nothing but Epi-
sema cceruleocephala.

f With regard to this compare G. R. Treviranus (Biologie, Band hi. 1805,
p. 265) ; Burmeister (Handbuch der Entomologie, Band i. 1832, p. 337); Lacor-
daire {Introduction a V etude de V 'Entomologie, torn. ii. 1838, p. 383) ; and
V. Carus (Zur ndheren Kenntniss des Generationswechsels, 1849, p. 21).

PARTHENOGENESIS.

19

particulars in the following words* : — w I have reared females of
Bombyx Pini, which, without any previous copulation, laid eggs
from which the caterpillars were developed, and passed through
all their transformations." Another case was mentioned by
L. C. Treviranus in these words f: — "I have myself been an
eye-witness, that a female of Sphinx Ligustri, which had been
developed from the pupa in my room during the night, and was
impaled upon a pin the next morning, laid numerous eggs on
the second day, from which caterpillars were evolved, exactly in
the same way as if a copulation with a male had taken place,
which most certainly was not the case." But when we remem-
ber what is stated above by the Theresians and Scheven, Trevi-
ranus5 simple assurance, that in the case of this female Sphinx
no copulation took place, will not suffice to remove all doubts
as to whether a male may not have come secretly and unobserved
and effected a copulation with this female, which might have
escaped the observation of Treviranus the more easily as he cer-
tainly did not previously think of a Parthenogenesis, or watch
the impaled female very closely. Still more unsatisfactory are
the very short statements of BurmeisterJ, in which nothing
further is said than that Dr. Al. von Nordmann observed a spon-
taneous development not long before in Smerinthus Populi, and
that a similar instance was known in Gastropacha potatoria.
Lacordaire5s statements § also, regarding Lucina sine concubitu in
Gastropacha Pini, and a case observed by Carlier, according to
whom three generations were produced from a specimen of Liparis
dispar without copulation, can only be received with distrust,
as we look in vain in them for any exact description of the em-
ployment of any of those precautions which are necessary in
such observations.

Another case of Parthenogenesis is said to have been observed
by Plieninger ||. He had reared several females of Gastropacha

* See Heusinger's Zeitschrift fur die organische Physik, Band ii. 1828, p. 263.
t See his Vermischte Schriften anatomischen und physiologischen Inhalts,
Band iv. 1821, p. 106.

X Handbuch der Entomologie, Band i. p. 337.
§ Introduction, torn. ii. p. 383.

|| See Wurtembergische naturwissenschaftliche Jahreshefte, Heft i. 1848, or
Schleiden und Froriep's Notizen aus dem Gebiete der JSatur- und Heilkuinle,
Band vii. 1848, p. 232.

c 2

20

SUPPOSED CASES OF

Quercus from the caterpillars, and pinned them immediately
after their exclusion. These deposited their eggs whilst impaled
upon the pins, and of these a great part were fertile, although in
this case, as Plieninger asserts, no fecundation had taken place.
He adds that the fertile eggs were distinguished from the barren
ones by their not collapsing like the latter, but retaining their
convexity until the exclusion of the young caterpillars. Whether
Plieninger actually watched for and saw the young caterpillars
quit their eggs, has not been mentioned. But even if we sup-
pose that the exclusion of the caterpillars really took place in
the present case, this phenomenon will certainly have come un-
expectedly upon Plieninger, and he will have omitted to guard
the impaled females with the necessary care, until the act of ovi-
position, against the access of males.

I must still refer to two cases which have commonly been cited
as evidence of a Lucina sine concubitu, but which upon closer
examination have nothing whatever to do with our question.

One of these cases relates to the Bombyx, Orgyia gonostigma,
the apterous female of which, Godart reared from the caterpillar*
and saw it lay fertile eggs without copulation, a statement which
not only astonished Godart, but also Lister f and GoezeJ. But
Swammerdam§ and Reaumur || have already stripped all the
marvellous from this relation, by showing that Godart had not
recognized the winged individuals of this species as the males
belonging to this moth, so that, without suspecting it, he had at
the same time reared the males of the species, which very probably
might have given occasion to a copulation with this female un-

* See Metamorph. et Hist. Nat., pars secunda, de Insectis, 1662, p. 106.
Experim. xxx.

t J. Goedartius, de Insectis cum notularum additione. Opera Lister. 1685,
No. 78 b. p. 190.

X See his Entomologische Beitrdge, Band iii. Th. iii. 1781, p. 9. I must,
however, remark here, that Goeze has incorrectly quoted from Lister (Godart)
No. 78 a and b to Bombyx antiqua, instead of No. 79. In a copy of Godart's
Metamorphosis with coloured figures, which I have now before me, it is per-
fectly clear that the moths and caterpillars copied from it in Lister's edition,
Nos. 78 a and b, belong to Orgyia gonostigma, and No. 79 to Orgyia antiqua.

§ See Biblia Natures, 1752, pp. 15 & 227-

|| See Memoires pour servir a VHistoire des Insectes, torn. i. part. i. 1737,
12mo, p. 409.

PARTHENOGENESIS.

21

perceived by him. The other case which is also usually reckoned
as a proof of a Parthenogenesis, relates to the observations made
by Pallas* upon Psyche graminella and Fumea nitidella, to which
I shall hereafter pay a closer attention (p. 24). Those cases of
Lucina sine concubitu which are supposed to have been observed
in Bees and Gall-flies, are also passed over here, as I must sub-
sequently subject them to a separate criticism.

If we glance once more over all the cases hitherto referred to,
which were supposed to give evidence of a Parthenogenesis, the
whole of them agree in that the soi-disant spontaneous evolution
of the brood was noticed accidentally and unexpectedly by the
observers, so that all those precautions which are necessary for
the attainment of a certain observation fulfilling all the require-
ments of science, were entirely neglected. For this reason,
therefore, we must doubt the correctness of the consequences
which the above-mentioned naturalists have derived from their
observations, and the more so, as we can directly oppose to these
observations, others which were made from the commencement
with the view of obtaining a certainty with regard to the possi-
bility of a spontaneous development of the unfertilized eggs of
insects, and which, with the employment of all the necessary
precautions, have only furnished negative results. As evidence
of this I may cite the multifarious observations of Reaumur,
Rosel, and the. Theresians, who never obtained caterpillars from
the eggs laid by unimpregnated female moths. Direct experi-
ments in rearing caterpillars from the unimpregnated eggs of
moths have been made by Kefersteint? according to his own
statements, in which however he always came to a negative re-
sult. But there is an observation made by Blancard and Aude-
bert upon Parthenogenesis in Spiders which may even be placed
in opposition to the above-mentioned inadmissible observations,
and this shows that the Spiders also are subjected to the general
physiological laws in their reproduction. Black wall J, namely,

* See Nova Acta Physico-medica Academics. Natures Curiosorum, torn. iii.
1767, p. 430: " Phalaenarum biga, quamm alterius Femma artubus prorsus
destituta, nuda atque vermiformis, alterius glabra quidem et impennis, attamen
pedata est, utriusque vero, sine habito cum masculis commercio, fcecimda ova
parit." f See Entomologische Zeitung, 1842, p. 90.

% See Annals of Natural History, 1845, vol. xv. p. 227.

22

SUPPOSED CASES OF

reared several young females of Agelena labyrinthica, Teyenaria
domesiica and Tegenaria civilis in a perfectly isolated condition,
and imprisoned in transparent glasses ; when these, after years
of care and feeding, had become full-grown, they laid eggs in
their virgin state, from which no brood was evolved.

The negative results obtained by these direct observations of
themselves furnished a sufficient ground for doubting the cor-
rectness of the cases of pretended Parthenogenesis above referred
to ; but the most convincing proof that observations of this kind
in general, which are only made by accident, and not designedly
contrived, must be received with the greatest distrust, as on such
occasions mistakes so easily slip in, is furnished by the following
epistolary communications. I am indebted to Herr W. von
LangsdorfT, of Lahr, for the following note: — "A female of
Gastropacha Quercus was evolved, which I took out of the
breeding-cage standing in my garden and carried into my
cabinet, which lies behind two rooms, where I placed it in an
open box ; the doors stood half open, as it was the height of
summer and very hot ; when I returned some time afterwards,
I found this female Bombyx in copulation with a male, which,
however, flew away swiftly on my arrival ; this female of course
laid fertilized eggs, whilst other females of G. Quercus which
were excluded soon afterwards, and which I had carefully im-
prisoned, certainly laid eggs, but these subsequently shrivelled
up, as they were unimpregnated. Now, had I come a little later,
when the male had already flown away, I should probably have
been deceived also, as the female Bombyx was in exactly the same
position as that in which I had placed it, and I could not have
supposed that a male Oak moth could slip so unperceived through
two rooms, in which there were several persons at the time, into
a third." Herr von Heyden wrote me a little while ago : " It is
remarkable, besides, with what acuteness certain male moths
scent out their females. Many years ago I saw a number of
males of Psyche pulla swarming about a closed window in my
sitting-room, and some of them settling on the panes. My
attention being attracted by this, I perceived that females of this
species had been evolved in a box standing in the room near the
window. I was acquainted with no locality for this species in
the neighbourhood of my dwelling." How easily, even in this

PARTHENOGENESIS.

23

case, if the windows had been imperfectly closed, might a copu-
lation of the female Psyches have been possible and yet have
remained unobserved ! What unexpected errors one may be
exposed to in such observations, is also shown by a communica-
tion made by Lucas*, according to which a male and female
moth were evolved from two pupae of the silkworm enclosed in a
common cocoon. It might be possible, if perchance both the
moths in such a common cocoon quitted their pupa-cases simul-
taneously, that they might have copulated in the interior of the
cocoon notwithstanding the narrow space ; and if then the female
alone had quitted the cocoon and laid eggs capable of develop-
ment, how easily might the still-concealed male have been over-
looked, and the case itself regarded as one of reproduction sine
concubitu !

* See Annates de la Societe Entomologique de France, torn. iii. 1845, p. lxxxii.

21

TRUE PARTHENOGENESIS IN SOME SAC-BEARING
LEPIDOPTERA.

From the statements previously published I was unable to
convince myself, that the possibility of a true Parthenogenesis in
the insect-world was established beyond all doubt. In what
way the observations so constantly repeated of a Parthenogenesis
in the Psychidte were to be received and explained,. I have shown
in a previous memoir in the Zeitschrift fur wissenschafiUche
Zooloyl?'*-. A mistake is the more possible in this case, as the
excluded footless females of the genus Psyche copulate in the
interior of their former caterpillar-sac, and alter the performance
of the copulation creep back again into the pupa-case, in order to
store it with fecundated eggs. A fertilized female Psyche of this
kind, which has retired completely into her pupa-case, has often
been regarded as an unexcluded virgin individual, whose power of
laving eggs capable of development could not but excite the
astonishment of those who were unacquainted with the mode of
life of the true P&ycfue. but could not in the least surprise any one
who was familiar with these mysteries. The Sac-bearers which
are separated from the true Psycnides according to the modern
system and referred to the genus Fumea. may also give rise to
similar errors, as, although their females, which are furnished
with six legs, do certainly quit the former caterpillar-sac after
their exclusion, and await the males clinging firmly to the out-
side of the sac by means of their laying-tube, yet, after copula-
tion has taken place, they stuff the pupa-case, which remains in
the sac, so completely from top to bottom with eggs and wool
from the extremity of their abdomen, that the full pupa-case, the
cleft thorax of which is thus completely pressed together and
consequently appears to be closed, may very easily be confounded
with a still unexcluded pupa.

After I had called attention to these important facts in the

x Band 1. 1S4:<. p. 9o. " On the Reproduction of Psyche.'

PARTHENOGENESIS IN LEPI DOPTERA.

25

history of the Psychidce, I nevertheless received assurances from
various Lepidopterologists that they had notwithstanding ob-
served a Parthenogenesis in the Psychidce, and felt certain that
they had made no mistake. All the more exact statements
referred to species of Sac-bearers, which are no longer considered
as true Psych idee, but are placed amongst the Tineidce, as the
genus Talceporia, or more properly Solenobia.

I felt myself incited by such communications to turn my
most particular attention to these little Sac-bearers, which I had
previously taken but little notice of, in which, being then in
Freiburg, I had to congratulate myself on the assistance of
Herr Reutti, a very able and credible Lepidopterologist. The
two species, Solenobia lichenella, Linn, and Solenobia trique-
frella, Fischer von Roslerstamm*, which are very abundant in
the immediate vicinity of Freiburg, offered themselves to our
observation, and of these, after my removal from Freiburg to
Breslau, I found I was able to make use of many specimens
at the latter place ; in Berlin also I collected at two different
times a great number of sacs of these two Solenobia, so that
during the years 1850, 1851, and 1852, I got together several
hundreds of these sacs, but to my greatest astonishment none
but female individuals were excluded from these sacsf, and only
a single locality furnished me with a couple of males of Solenobia
triquetreUa.

I was enabled to observe that these virgin female Sac-bearers,
which I constantly watched in little vessels closed with glass-
lids, clung firmly to the outside of their sacs, in the same
fashion as the females of Fumea nitidella, and filled the sac with
eggs by pushing in their laying-tubes ; however, these female
Solenobice differed from the female Fumece in this respect, that
the former in escaping and creeping out dragged the pupa-case
with them quite out of the sac. The pupa-case then remained

* In regard to the determination of these two species of Sac-bearers, I refer
to Zeller's classical description of the genera of Tineacea, in the IAnruea
Entomologica, Band vii. 1852, p. 343.

_t Wocke also collected about 600 sacs of Solenobia lichen ell a in the vicinity
of Breslau, from which he did not obtain a single male. See the thirty-first
Jahresbericht der Schlesischen Gesellschaft fur vaterldnclische Cultur iiber das
Jahr 1853, p. 182.

26

PARTHENOGENESIS IN SOME

at first sticking loosely into the posterior free opening of the
sac, which was firmly spun down, but also frequently fell down,
so that the female Solenobice always lay their eggs immediately
in the sac itself. The females of the sac-bearing genus Talce-
poria, which approaches most closely to Solenobia, proceed in
exactly the same way in escaping and laying their eggs.

But what particularly struck me in the behaviour of the female
Solenobice, was the circumstance that they commence the busi-
ness of oviposition very soon after their exclusion, whilst the
females of Fumea put off their egg-laying until they have copu-
lated, by which means many of the latter in my breeding-cages,
in which there was sometimes a deficiency of males, died of
vain expectation in their virgin state, without having previously
discharged their eggs. The female Solenobice, on the contrary,
possessed such a violent impulse to lay their eggs, that when I
removed them from their sacs, they pushed their laying-tube
about in search of the orifice of the sac, and at last let their
eggs fall openly. If I had wondered at the zeal for oviposition
in these husbandless Solenobice, how was I astonished when all
the eggs of these females, of whose virgin state I was most
positively convinced, gave birth to young caterpillars*, which
looked about with the greatest assiduity in search of materials
for the manufacture of little sacs !

After I had been first surprised by this phasnomenon in the
spring of the year 1850, I could not but be convinced that De
Geer, Scriba, and Speyer, who reported that these animals laid
fertile eggs without previous copulation, had not deceived them-
selves, as I previously supposed t ; nevertheless, I could not
persuade myself that this phenomenon was to be explained as
Parthenogenesis, but rather thought I recognized in the whole
phenomenon, an asexual propagation analogous to the repro-
duction of the Aphides, regarding the female Solenobice which
had laid eggs capable of development without copulation as
asexual nurses. In this way I quieted myself with the idea that
an alternation of generations occurred in the insect-world, not

* This production of fertile eggs without previous copulation has also been
observed in Solenobia lichenella by AVocke {op. cit. supra, p. 182) and Reutti
(see Beitrage zur rheinischen Naturgeschichte, Heft 3, 1853, p. 176).

t See my memoir above referred to, on the Reproduction of Psyche, p. 99.

SAC-B EARING LEPIDOPTERA.

27

only amongst the Aphides, but also amongst some moths*.
Subsequently, however, the thought occurred to me, that by the
careful dissection of these questionable Solenobia-nurses, a much
greater anatomical difference ought to be exhibited between
them and the females of Solenobia than between the Aphis-
nurses which produce living young and the egg-laying female
Aphides f; for it is well known that all female Lepidoptera
possess two sexual orifices, one behind the other, of which the
extreme or hindmost one serves for the deposition of the eggs,
whilst the second orifice, placed before this (anteriorly), has to
receive the male generative organ during the act of copulation.
If these moths which laid eggs capable of development were
nurses, I expected, on examining them carefully, to find neither
the second sexual orifice on the exterior, nor the copulative
pouch (bursa copulatrix) and seminal receptacle in the interior,
parts which I had previously found in all female Lepidoptera J.
I was, however, quite deceived in my expectations, for all those
TalceporicB which had been at first regarded by me as nurses,
proved, without exception, to be perfectly developed female
moths ; they all possessed the double sexual orifice, the copulative
pouch, and seminal receptacle, arranged and developed in the
same way as in other female Lepidoptera. The copulative pouch
and seminal receptacle were always empty and unexpanded.
Moreover no difference was discoverable (as to number, form
and contents) between the ovaries of these supposed nurses and
the same organs in other female Lepidoptera ; in short, I con-
vinced myself in the most positive manner, that in this case we
had nothing to do with nurses, but with virgin females §.

After this discovery, the name of Parthenogenesis, which the
English naturalist Owen applied to the alternation of genera-
tions, must be peculiarly the most suitable denomination for the

* See my Bemerkungen uber Psychiden, in the JahresbericJit der Schlesis-
chen Gesellschaft fur vaterldndische Cultur uber das Jahr 1850, p. 84 ; re-
printed in the Entomol. Zeitung, 1851, p. 341, and in the Transactions of the
Entomological Society of London, vol. i. 1851, p. 234.

f See Froriep's Neue Xotizen, Bd. xii. loc. cit. supra.

X See Miiller's Archiv, 1837, p. 417.

§ I have already called attention to this fact at the meeting of German
naturalists at Gotha, as appears from the short notice in the Tagblatt der
2^ten Versammlung deutscher Naturforscher und Aerzte, No. 3. p. 28.

28

PARTHENOGENESIS IN SOME

reproductive process just described by me in Solenobia trique-
trella and lichenella.

The two species of Sac-bearers just mentioned are not however
the only representatives of the true Parthenogenesis ; an equally
striking example of the virgin reproduction of a female insect is
presented by Psyche Helix. Of this extremely remarkable moth
we are at present only certainly acquainted with the female. Tn
the caterpillar state it lives in a sac, which in its form resembles
a sinistral snail-shell, to which similarity the specific name given
by me to this Psyche also refers.

The sac of Psyche Helix is nearly as large as a small pea
(generally 2 lines Rhenish in height, and the same in breadth) ;
it exhibits three and a half whorls (figs. 1-3), and consists of a
firm whitish tissue, which is thickly and firmly coated externally
with small particles of earth. The colour of the sac is usually
earthy-grey, but in certain districts blackish or reddish-brown
sacs occur ; this is probably in connexion with the colour of
the soil from which these Sac-bearers partly derive the material
for their sacs. Here and there also individual cases occur with
separate whorls (anfractibus devolutis). The uppermost and
narrowest half-turn is always very indistinct, and generally ap-
pears collapsed. At the place where the second whorl com-
mences there is always a lateral opening (figs. 2, 3, & 6 a), the
margins of which usually lie down and conceal the entrance
to the cavity of the whorl*. When the caterpillar has evacu-

* Besides Psyche Helix, there are some other insects, whose larvae, as case-
bearers, manufacture sacs in the form of a snail-shell. In the genus Psyche
itself there occurs another species, the caterpillars of which, like those of
Psyche Helix, bear about with them a spirally-twisted sac. By the kindness
of Herr Zeller of Glogau and Dr. Rosenhauer of Erlangen, I possess two
earth -coloured, snail-like sacs with perfectly flat convolutions (figs. 15-17),
found in Sicily and Spain. They are nearly three times as large as the sacs
of Psyche Helix, and from their different form and size belong to another spe-
cies, to which I will give the provisional name of Psyche Planorbis. Both
sacs, like those of Psyche Helix, are covered with fine grains of earth and sand
cemented on them. Behind the uppermost and narrowest half-turn there is also
a lateral aperture, which is due to an interruption in the walls of the sac taking
place here (fig. 15a). In the family of the Phryganidce also, larvae occur,
which form a spirally-twisted domicile. The first notice of this was furnished
by Shuttleworth (in the Mittheilungen der naturforschenden Gesellschaft in
Bern, June 1843, p. 20), and as this is but little known, I will reproduce it

SAC-BEARING LEPIDOPTERA.

29

ated its faeces, it pushes them out of this aperture, when the
edges of the latter rise a little. This lateral opening of the sac

here literally. The passage in question runs as follows : — " Amongst the
Mollusca collected by Blauner in Corsica, there was a considerable number of
a shell, which was at first taken for an undescribed species of Valvata, and
which appeared to be nearly allied, if not identical, with the Valvata arenifera
of Lea (Observ. p. 114. tab. 15. figs. 36 a & b), from North America. The
perfectly regular, spirally convoluted shell consists of a very fine transparent
membrane, upon which very small grains of sand and stones are fixed with the
greatest regularity. The circular orifice is closed by a very delicate, appa-
rently spirally convoluted, membranous operculum. The general form, as well
as the dimensions, remind one strikingly of the Valvata depressa, Pf. In all
the individuals provided with an operculum, there was either the larva or the
nympha of an insect, probably belonging to the genus Phryganea, which, bent
into a half-spiral, lay singly in each shell. Under the microscope, the oper-
cula exhibited, besides the spiral or regularly concentric structure above
referred to, an excentric longitudinal opening running parallel to the inner
margin. Specimens of the Valvata arenifera of Lea, which I have recently
obtained from Vienna, exhibit precisely the same structure both of the shell
and operculum. In Reaumur's Memoires pour servir a VHistoire des Insectes,
torn. iii. p. 193. pi. 15. figs. 22-24, there is a short description and figure of a
(spirally-convoluted) Phryganea-c&se (occurring in Switzerland). This species
of Reaumur's, however, differs in every other particular from the species above
described, and also appears to possess no operculum." The case last referred
to by Shuttleworth belongs to Psyche Helix ; the other one, which resembles
a Valvata, on the contrary, is a very different thing (see my figures 18-22),
and is certainly produced by a Phryganidous insect. I saw several of the
habitations of this insect in Bremi's collection at Zurich, partly collected in
Corsica and partly on the Lake of Como. Bremi has given the name of
Helicopsyche Shuttleworthi to the questionable Phryganidan from which
these spiral cases are derived ; and many specimens of a similar smaller case
have been since sent to him from a brook in Porto Rico, the inhabitant of
which Bremi has named Helicopsyche minima. By the kindness of Herr Bremi
I have obtained several specimens of both kinds, which are essentially different
in their structure from the sacs of Psyche Helix. As regards their size, the
diameter of the largest sacs of Helicopsyche Shuttleworthi is 2 lines (Rhenish),
and of those of H. minima 1 line. A principal distinction between these Phry-
ganidan domiciles and the spiral sacs of Psyche consists in the fact, that whilst
in the case of Psyche Helix extremely fine grains of sand are stuck as a coating
upon the outer surface of the white web of the sac-walls, in Helicopsyche the
walls of the habitation are formed directly and solely of larger, polygonal par-
ticles of sand, closely cemented together from within and without. The cater-
pillars of Psyche also never close their sacs with an operculum. But that the
Helicopsyche-s&cs are really produced by a Phryganidous insect, I ascertained
from the contents which I extracted from two cases of Helicopsyche minima

30

PARTHENOGENESIS IN SOME

is really due to an interruption, which the walls of the sac ex-
hibit at this point in almost the whole of their transverse diameter.
The body of the caterpillar is indeed also spirally curled (figs. 4
and 7)) but in its form and length it only corresponds with the
lowermost whorl of the sac. In this way it would be impossible
for the caterpillar to push its body up into the uppermost narrow
whorl for the evacuation of its faeces. The female of Psyche
Helix, like all females of Psyche, after completing the business
of oviposition, quits its sac, which is firmly spun down by its
anterior aperture, and for this purpose it makes use of the lateral

still furnished with opercula. These consisted of a dried pupa, which in the
form of the legs and of the long antennae, the four hairy rudiments of wings,
and the two biting jaws, exactly resembled a Phryganidan. The description
given by Lea of his Valvata arenifera (in his Observations on Najades and
Descriptions of new species, vid. Transactions of the American Philosophic al
Society, vol. iv. Philadelphia, 1834, p. 104. pi. 15. fig. 36 a, b. See my copies,
figs. 23, 24) runs as follows : — " Testa orbiculata, convexa; anfractibus tribus,
qui arenis agglutinatis operiuntur; umbilico lato; spira obtusa. Hab. Cum-
berland River near Nashville. Length four-twentieths of an inch. Remarks. —
This very curious and interesting species was among the freshwater shells so
disinterestedly sent to me by the Lyceum of Natural History of New York, to
be examined and inserted in this paper. It has the singular property of
strengthening its whorls by the agglutination of particles of sand, &c, by
which it is entirely covered, and in this character it resembles the Trochus
agglutinins, Lam. (Trochus conchyliophorus, Authors). The apex, in all the
specimens which I have had an opportunity of examining, is broken. The
operculum was observed in two specimens sufficiently perfect to exhibit a
striated horny structure."

The sacs of Helicopsyche minima commimicated to me by Bremi, agree
almost perfectly with this shell of Valvata arenifera described and figured by
Lea. Even the bronze-green colour is common to both of them. The pre-
sence of an operculum is also in favour of the derivation of this habitation
from a Phryganidous insect, as the Sac-bearers amongst the Lepidoptera form
no operculum, but always spin down their sac by its lower aperture to foreign
substances. Moreover, the opercula, of which I found several in my specimens
of the sac of Helicopsyche minima, had also a striated appearance like those of
Valvata arenifera. They were smaller than the aperture of the sac, and con-
sequently only closed it imperfectly. On examining them with the micro-
scope, I detected a fibrous structure in these opercula, arising from compara-
tively coarse-spun threads, sticking close together; at the margins of these
opercula single threads protruded, by which they were united with the mouth
of the sac. In my specimens of the sacs of Helicopsyche Shuttleworthi I per-
ceived no opercula ; they had probably fallen off, or perhaps were not formed
when these sacs were collected.

SAC-BEARING LEPIDOPTERA.

31

opening in the hinder whorls of the sac, although the animal
with its empty, shrivelled body could easily force its way out
through the uppermost narrow whorl, and through the narrow
aperture at the apex of the sac. But there is probably another
circumstance which prompts the caterpillar instinctively, whilst
finishing and enlarging its sac, to introduce a lateral opening
below the uppermost narrow whorl ; I mean the eventual per-
mission of the act of copulation, which in this case, from the
peculiar form of the sac, could only be effected through a low
lateral aperture of this kind.

This Sac-bearer was first mentioned by Reaumur*, but has
since remained entirely unnoticed by entomologists. It is only
very recently that greater attention has been given to these
Heliciform caterpillar-sacs. My attention was first called to
this Sac-bearer in Freiburg in the latter part of the summer of
1849 by Yon Heyden, to whom entomology is indebted for so
many interesting discoveries. It was discovered by Von Heyden
spun down on rocks on the Schlossberg near Freiburg, and sub-
sequently the same animal was found on the Isteiner Klotz be-
tween Freiburg and Basle t. This Sac-bearer was forwarded to
me by Zeller from the neighbourhood of Glogau, and I received
several living specimens, collected a couple of miles from Vienna,
near Modling, through the kindness of Kollar, in whose com-
pany I afterwards (in the year 1850) collected many specimens
in the same locality. Dr. von Frantzius also brought me some
specimens of this Sac-bearer from Meran. By Herrich-Schaffer's
intervention, I obtained many of the same sacs from the district
of Tegernheim near Ratisbon, and this Sac-bearer was also ob-
served by Mann and Zeller in Sicily J. Besides the habitat
given by Reaumur, Besancon and Dijon in France have recently
been indicated by Bruand as localities for this Sac-bearer §. In

* See Memoir es pour servir a VHistoire des Insectes, torn. iii. part i. edit.
12mo, p. 249. pi. 15. fig. 20-22, figures of the sac of Psyche Helix (see the
copies of these in my plate, figs. 10-12).

t See Reutti's Uebersicht der Lepidopteren-Fauna des Grossherzogthums
Baden, in the Beitrdge zur rheinischen Xaturgeschichte, Heft 3. 1853, p. 49.

X See my Bemerkungen iiber Psychiden, in the Jahresbericht der schlesischen
Gesellschaft fur vaterldndische Cultur iiber 1850, p. 87 (transl. Ent. Trans.
new ser. vol. i.).

§ See his Essai monographique sur la Tribu des Psychides, in the Memoires

32

PARTHENOGENESIS IN SOME

B re mi's collection at Zurich I saw specimens of this sac, which
had been sent from Ticino and the Yalais. By the kindness of
Dr. Rosenhauer of Erlangen, I obtained a spiral sac, which was
found near Malaga in Spain, and which, from its size, probably
belongs to a species distinct from Psyche Helix. The form of
this sac is exactly the same, but its breadth is 3 lines and its
height 2f lines.

The caterpillar of Psyche Helix selects various plants for its
nourishment. On the Schlossberg near Freiburg it feeds upon
Artemisia vulgaris. According to Zeller's testimony it also lives
upon Anthyllis vulneraria, Lotus corniculatus, and Gnaphalium
armarium. Kollar found his on Atriplex laciniata. Near Ratis-
bon I observed these sac-bearing caterpillars feeding upon
Alyssum montanum and Teucrium Chamceclrys. It is also stated
by Bruand, that besides Cheiranthus odoratus and Scabiosa
arvensis, this Sac-bearer was most frequently met with upon
Teucrium Chamcedrys. Reutti fed these caterpillars with Lamium
purpureum, and I myself supplied them with Lotus corniculatus
and Hippocrepis comosa. These Sac-bearers are leaf-miners
after the fashion of the caterpillars of Coleophora, pushing their
bodies far in between the epidermic plates of the leaves, through
a round hole which they gnaw in the latter, and devouring the
chlorophyll all round them, during which process the sac re-
mains outside sticking with its aperture to the opening in the
epidermis. The leaves, and even the variegated flowers of the
food-plants are in this way often completely decolorized by the
Sac-bearers. The caterpillars of Psyche Helix are of a dirty
white colour; the head, the legs, the three thoracic segments,
and the extremity of the abdomen possess a hard, blackish-
brown integument. The constrictions of the thorax and also its
median line are colourless (figs. 2, 4, 6 & 7) • When taken out of
the sac, the caterpillar, in creeping about, retains the same
gentle spiral curvature of the body as when within the sac.
When these Sac-bearers are full-grown, which is the case in
the latter part of the summer, they quit their food-plants like
the other caterpillars of the Psy chides and seek a suitable place
for their change to the pupa state. When they find stone walls

de la Societe d' Emulation du Doubs, Annee 1852, p. 74. pi. 2. fig. 48 b (sac of
Psyche Helix).

SAC-BEARING LEPI DOPTER A.

33

or rocks in their vicinity they creep high up on them, and spin
down the lower aperture of their dwelling firmly. In passing
through the process of moulting also, these caterpillars, like
all other Sac-bearers, always spin down their habitations tem-
porarily. The evolution of the moth takes place in the same
year*. If after some time we examine the spun-down sac of a

* This Sac-bearer, like the other Psychidce, is exposed to the attacks of
Ichneumonidce. It is remarkable that the Ichneumonidous parasite of Psyche
Helix is a Chalcis, whilst I have never yet reared a Chalcis from the caterpillars
of the other Psychidce. This Chalcis, which was indicated to me by Kollar
under the name of Chalcis nigra, does not, however, appear to occur very gene-
rally. Reaumur obtained it from the sacs of Psyche Helix found in France,
as appears from his notice, short as it is (see Mem. pour serv. a, VHist. des Ins.
torn. hi. p. 250); the sacs collected near Modling also furnished me with this
Chalcis in abundance ; but on the other hand, from more than a hundred sacs
which I had obtained from Tegernheim near Ratisbon, no Chalcis, and indeed
no Ichneumon at all, escaped. The Chalcis always eats its way out at the side
of the sac between the first and second whorls, and leaves a round hole corre-
sponding with its size on the outside of the sac (fig. 1 b). This Chalcis (figs.
13, 14) belongs, according to Nees von Esenbeck's Hymenopterorum Ichneu-
monibus affinium Monographice, vol. ii. p. 27, to the species of the genus Chal-
cis described in Sectio II. (abdominis petiolo brevissimo); its specific character
may be diagnosed in the following manner : — nigra, pubescens, scutello in me-
dio marginis dente obtuso, femoribus posticis subtus obsolete unidentatis, tar-
sis piceis. Long. lin. 1 — 1|. The other Ichneumons reared by me from the
caterpillars of Psychidce are as follow : —

Campoplex difformis, Gr., from Fumea nitidella, Ochs.

laetus, Rtzb., from Fumea betulina, Zell.

lugens, Rtzb., from Fumea nitidella and betulina.

psilopterus, Gr., from Solenobia lichenella, Linn.

Cryptus eborinus, Rtzb., from Fumea nitidella.

spiralis, Gr., from Talaeporia pseudobombycella, Ochs.

Hemiteles albipennis, Rtzb., from Solenobia triquetrella, Fisch. v. R.

areator, Gr., from Psyche calvella, Ochs. and Fumea nitidella.

elongatus, Rtzb., from Talajporia pseudobombycella.

gastroccelus, Rtzb., from Solenobia triquetrella and lichenella.

imbecillus, Gr., from Fumea nitidella.

leucomerus, Rtzb., from Solenobia triquetrella, Fisch. v. R.

melanarius, Gr., from Solenobia triquetrella.

similis, Gr., from Psyche calvella.

tristator, Gr., from Fumea nitidella.

1 nov. sp. from Fumea betulina.

2 nov. sp. from Tahcporia pseudobombycella.

Microgaster longicauda, Wesm., from Solenobia lichenella.

Pezomachus agilis, Gr., from Psyche calvella. [Pezomachus

D

34

PARTHENOGENESIS IN SOME

Psyche Helir during its period of pupation, we find the pupa in
the lower whorl of the ease, with its anterior extremity directed
upwards, and its hinder extremity downwards towards the
attached lower aperture. Between this and the extremity of the
abdomen of the pupa, the shrivelled skin of the caterpillar stripped
off in its last change of skin is always fixed, so that this cater-
pillar, like all the caterpillars of the Psychidie. turns itself round
in the sac before the true pupation. In all the sacs of Psyche
Helix in the pupa state, hitherto examined by me, of which I
have had the opportunity of observing more than a hundred and
fifty within seven years. I never found any but a female pupa.
This is motionless, of a yellowish-brown colour, and with very
indistinct segments : it presents a body which is slightly dimi-
nished in front, and gently curved in a spiral form corresponding
with the lower spiral whorl of the sac (fig. 5).

The wingless and almost footless female moth which is evolved
from this pupa, also appears slightly curved in a spiral (figs. 8. 9).
Its colour is grey, with a very slight brown tint on the back of
the three thoracic segments. The anterior extremity of the body
is somewhat narrowed : the exantennate head, which is strongly
bent downwards, exhibits very indistinct and quite abortive oral
organs : and on each side of it two dark pigment-spots are per-
ceptible, which however contain no eye-facets. The abdomen
is sparingly beset with white hairs. The varicose urinary vessels
shine through the skin of the body here and there with a whitish-
yellow colour, as does also the violet ventral chain of ganglia.
The movements of these females of Psyche are extremely sluggish,
and the six little feet of the three thoracic segments, which are in

Pezomaehus eursitans. Gr.. from Psyche graminella. Ochs.

geochares. Forst.. from Fumea nitidella.

pedestris. Gr.. from Psyche calvella and Fumea nitidella.

1 nov. sp. from Psyche calvella.

2 nov. sp. from Psyche calvella.

Phygadeuon tenuipes. Gr.. ? from Fumea nitidella.
Pimpla annulicornis. Rtzb.. from Psyche graminella.

exaniinator. Gr.. from Psyche graminella, Fumea betulina and niti-

delk.

scanica, Gr.. from Psyche calvella and Fumea nitidella.

Pteromalus Zelleri, Rt:b., from Fumea nitidella.

SAC-BEARING LEPIDOPTERA.

35

the form of very short conical processes, scarcely take any part in
them. A dissection which I made of several of these animals,
convinced me that I really had female insects before me ; the
internal and external organization of their sexual organs being
exactly the same as in other females of Psyche. The two sexual
orifices presented themselves in all the individuals, as well as the
copulative pouch and seminal receptacle, both of which of course
were always empty. The eight ovarian tubes only contained a
very few eggs.

Like all other true species of Psyche these female moths de-
posited their yellowish eggs in the empty pupa-case, which, in
Psyche, always remains behind in the caterpillar- sac ; they then
shrivelled up to a very small volume, when they generally left
the sac by the above-mentioned lateral aperture and soon after-
wards died.

The unfertilized eggs, concealed in the pupa-case, are also
developed in the same year. If a spun-down sac of Psyche
Helix be opened in the latter part of the autumn or in winter,
we always find from ten to four-and-twenty young, reddish-grey
caterpillars in the interior of the pupa-case. On the empty
colourless egg-shells, which may be found crushed between the
caterpillars, the micropyle is distinctly recognizable under the
microscope.

After I had thus never detected any other mode of reproduc-
tion but that by Parthenogenesis in Psyche Helix, it necessarily
astonished me that other entomologists should have succeeded
in obtaining the males of this species. On a closer examination,
however, it appears doubtful whether the moths described as
males of Psyche Helix really belong to this species. Thus the
male of a Psyche helicinella was figured by Herrich-SchafFer,
together with a sac of Psyche Helix*. The moth figured was
discovered by Mann in Sicily : as an empty sac of Psyche Helix
occurred in its vicinity, Mann supposed that the moth had escaped
from this sac. Herrich-Schaffer himself, however, leaves it doubt-
ful, whether this spiral sac really belonged to the moth figured
by him, saying, " the sac (if really belonging thereto) is like a
snail-shell, formed only of grains of sand, without portions of

* See his Systematische Beschreibung der Schmetterlinge von Enropa, Band
ii. p. 21. figs. 108, 109.

D 2

36

PARTHENOGENESIS IN SOME

plants." For this reason I have retained the name of Psyche
Helix, which I gave to the female moths reared by me from the
snail-like sacs, as it is not yet proved that the Psyche helicinella
of Herrich-Schaffer actually belongs to my Psyche Helix. The
same applies to the male moth described and figured by Bruand
as Psyche helicinella*. Bruand describes as belonging to Psyche
helicinella, the female and sac-bearing caterpillar of my Psyche
Helix, but says expressly, that he has never been able to rear this
Sac- bearer to the evolution of the mothf. From this, there-
fore, we have no certainty that the winged individuals of Psyche
helicinella, taken in the open air by Bruand, are the males of my
wingless female Psyche Helix. As the males of Psyche copulate
with their females whilst concealed in the interior of the sac, and
for this purpose push their abdomen into the hinder free aperture
of the female sac, the male of Psyche Helix will also perform
this action, and will therefore probably possess an abdomen
curved to correspond with the convoluted sac of the female. No
such curvature of the abdomen is perceptible in either of the
males figured by Herrich-Schaffer and Bruand, from which my
doubts above expressed gain still greater support. Further
observations, therefore, are to be made as to the existence of the
male individuals of Psyche Helix. Perhaps those two flat spiral
sacs which I have previously described (p. 28 note*) as belonging
to a distinct species of Psyche (Ps. Planorbis) may be produced
by the caterpillar of the male Psyche Helix, which would be by
no means very improbable, as the caterpillar-sacs of certain other
Psychida differ in form and size according to the sexes. The
most striking example of this kind is presented by Solenobia

* See his Essai monographique, 8fc. ut cit. supra, p. 73. pi. 2. fig. 48 a.

f Upon this Bruand expresses himself (p. 74) in the following manner : —
" Cette chenille est fort difficile a elever, et, pour ma part, apres trois essais
successifs, j'ai renonce a obtenir le papillon en domesticite. II est probable
que quelques circonstances atmospheriques (la rosee matinale, par exemple)
sont necessaires a son eclosion. La chenille se nourrit tres-bien jusqu'au
moment de sa transformation ; alors elle commence a errer ca et la dans le
vase ou la boite qui la renferme, enfin elle se fixe aupres les parois .... puis
rien n' arrive ; elle meurt miserablement." With me, the rearing of these Sac-
bearers after they were nearly full-grown, to the evolution of the female, has
not been attended with difficulty, in spacious airy breeding-cages, and with a
constant supply of fresh food (Lotus corniculatus).

SAC-BEARING LEPIDOPTERA.

37

clathrella, Zell.* I also leave it undecided, whether that larger
sac already mentioned by me (p. 32), which, except in its size,
differed in nothing from the sacs of the female Psyche Helix,
does not belong to a caterpillar, which might have become
developed to a male individual of Psyche Helix f.

* See Zeller's Beschreibung des m'dnnlichen und weiblichen Sackes der Sole-
nobia clathrella, in the Linncea Entomologica, Band vii. 1852, p. 345. See
also Fischer von Roslerstamm, Abbildungen zur Berichtigung und Ergdnzung
der Schmetterlingskunde, p. 84. taf. 38.

f [May not the Psyche Planorbis and the larger heliciform-sac, both from
Spain, be the male and female sacs of one species, and the male sac of P. Helix
be also Planorbis-like, but smaller than the Spanish specimens? — W. S. D.]

38

TRUE PARTHENOGENESIS IN THE HONEY-BEE.

Whilst I was occupied with my task of establishing a Partheno-
genesis in Psyche Helix, and Solenobia triquetrella and lichenella,
I did not omit to bring within the limit of my investigations
other insects also, of which the story went that the females were
capable of independent reproduction in the virgin state without
the assistance of a male individual. It was of importance to
look carefully at the Honey-Bee, upon the reproduction of which
the most extraordinary statements have been made at all times
by the various Bee-keepers. Amongst these statements my
attention had already long been turned to that remarkable faculty
which was ascribed to certain Worker-Bees, and which was said
to consist in their being able to lay eggs capable of development
without copulation*. In the year 1851, therefore, I put myself
in communication from Breslau with various Bee-keepers, and
in this way became acquainted with the distinguished Apiarian
Dzierzon, pastor at Carlsmarkt near Brieg in Silesia. By this
Apiarian, who is gifted with an admirably acute power of ob-
servation and free from prejudices, I was furnished, partly in
letters and partly by word of mouth, with information upon
the ceconomy of Bees and the most important phaenomena of
Bee-life, of a kind such as I could never have obtained from zoolo-
gical and entomological works. What surprised me most in these
communications, was the entirely new theory of reproduction
which Dzierzon had established, with which he then made me

* [Hunter, in his paper "On Bees," Phil. Trans. 1/92, refers to this opinion,
but had been unable to confirm it. " It is asserted by Riem, that when a hive
is deprived of a queen, labourers lay eggs."..." and TYilhelm says that it is
the labourers only that lay drone-eggs." Hunter then quotes from Schirach : —
"A young queen lately hatched was put into a hive, which had been previously
ascertained to contain no drones, and whose queen was removed ; and yet the
young queen laid eggs." Upon which he remarks — " There is no mystery in
this ; but did they hatch ? " The definite reply to this question, and the nature
of the product of the virgin-egg, are amongst the valuable facts in the present
work. — R. O.]

PARTHENOGENESIS IN THE HONEY-BEE. 39

acquainted, and by which all the phenomena relating to the
process of reproduction in the Bees, which so often border upon
the marvellous, may be completely explained.

One of these remarkable phaenomena is the property just
referred to possessed by some Worker-Bees of laying eggs capable
of development, a property which is denied by no observant Bee-
keeper, but could not hitherto be satisfactorily explained in any
way. The dissection of the Worker-Bees had shown, that they
possess undeveloped ovaries, that the seminal receptacle is only
imperfectly developed in them, and that, by reason of the abor-
tion of their copulative organs, they are by no means in a condi-
tion to copulate with a Drone (a male bee) and allow themselves to
be fertilized by him. But whence then should this reproductive
faculty of certain Worker-Bees arise ? At first I attempted to
bring this reproductive power into connexion with the Alterna-
tion of Generations, and expressed the supposition* that similar
circumstances might occur amongst the Bees as amongst the
Aphides, and that consequently amongst the Bees individuals
were produced at certain times, which, as nurse-like creatures,
could produce brood, without fertilization. But if nurses
really did occur in the Bee-colonies, these must have been
recognizable by careful dissection, as instead of ovaries they
would contain germ-stocks, and no trace of a seminal receptacle.
I at the same time expressed the wish that I might soon have
an opportunity given to me of submitting Bees, which had been
ascertained to be fertile workers, to a careful dissection and
microscopic examination, in order to decide whether or no they
really were nurses.

But when I became acquainted with Dzierzon's theory of the
propagation of the Bees, and constantly grew more and more
convinced of its correctness, it was evident to me that we cannot
speak of a nurse-formation amongst the Bees. To inform my-
self as completely as possible about this theory, I went myself
to Carlsmarkt and held a conference with Dzierzon on the 26th
July 1851, in which I opposed all possible doubts to his theory

* See my Bemerkungen uber die Lebensweise und den Haushalt der Bienen,
in the Jahresbericht der schlesischen Gesellschaff fur vaterlandische Cultur im
Jahre 1851, p. 48.

40

PARTHENOGENESIS

of reproduction ; but these were constantly set aside by him, and
with such convincing reasons, which could be brought into
accordance both with the anatomical relations of the Bees and
with the physiological laws of insect and animal life in general,
that at last I could no longer hesitate in admitting the correctness
of Dzierzon^s theory of reproduction.

Dzierzon expressed his views upon the reproduction of Bees
in the year 1845 in the Bienenzeituny of Eichstadt*. but without
particularly emphasising the most important details of his theory,
and without elevating it into a peculiar theory. I consider it
necessary to reproduce the views expressed by Dzierzon in that
Journal, word for word. They run as follows: —

u Presupposing, what will be referred to and proved in the
following Numbers, that the Queen (female bee) to become good
for anything must be fertilized by a Drone (male bee), and that
the copulation takes place in the air, I express the conviction,
from which all phenomena and mysteries may be perfectly
explained, that the drone-eggs do not require fecundation ; but
that the cooperation of the Drones is absolutely necessary when
Worker-Bees are to be produced. Whilst in the higher animals
the male is the perfect and ruling creature — the bull keeps to-
gether and as it were governs the herd of cattle, and the cock
does the same by the hens — the reverse of this takes place in
Insects. In the Wasps, Hornets, Humble-Bees, Ants, and espe-
cially in the Bees, the perfect female forms the central point and
holds the swarm together. As even the drones are subordinated
to her, they are also in themselves altogether imperfect creatures,
for the production of which so many forces and conditions are
not necessary even on the part of nature as for the production
of the queen, and, what is the same thing, of the workers. (The
ancients even appear to have indicated this by the denomination
Fucus.) The truth of this assertion appears at once from the
fact, that as everything that is capable of the more difficult and
greater effect may also produce the easier and smaller one, so
every stock, which is in a condition to produce worker-bees, may
also produce drones, when suitable cells are not wanting in the
nest; but not inversely. In copulation the ovaries are not

* See Bienenzeitung, herausgegeben von Dr. C. Barth und A. Schmid in
Eichstadt. Jahrgang i. 1S45, p. 113.

IN THE HONEY-BEE. 41

fecundated, but the seminal receptacle, that little vesicle or knot
which in the young queen is filled with a watery moisture, is
saturated with semen, after which it is more clearly distinguish-
able from its white colour. The activity of the ovary in the
normal state only commences after copulation, but is not neces-
sarily caused thereby ; hence many unfecundated queens lay no
eggs at all, whilst others lay drone- eggs; and even workers do
the latter, although, from their want of a seminal receptacle, I
regard them as quite incapable of copulation. I am convinced
that such eggs are sufficient for the production of drones, whilst
the egg from which a queen or a worker is to be developed must
come in contact with the filled seminal receptacle. This is cer-
tainly only a hypothesis, and will probably remain so, but one to
which every close observer will be no more able to refuse his
assent, than the hypothesis of Copernicus, that the earth turns
round upon its axis ; for all the mysterious phaenomena in the
commonwealth of the Bees are very simply explained by it."

In a separate Bee-book, Dzierzon subsequently summed up
his views upon the reproduction of Bees as a regular theory in
the following manner * : —

" Therefore, and this must be well borne in mind, in the
copulation of the queen, the ovary is not impregnated, but this
vesicle or seminal receptacle is penetrated or filled by the male
semen. By this, much, nay all of what was enigmatical is
solved, — especially how the queen can lay fertile eggs in the early
spring, when there are no males in the hive. The supply of
semen received during copulation is sufficient for her whole life.
The copulation takes place once for all. The queen then never
flies out again, except when the whole colony removes. When
she has begun to lay, we may, without scruple, cut off her
wings ; she will still remain fertile until her death. But in her
youth, every queen must have flown out at least once, because
the fertilization only takes place in the air ; therefore no queen,
which has been lame in her wings from birth, can ever be per-

* Theorie und Praxis des neuen Bienenfreundes, oder neue Art der Bienen-
zucht mit dem giinstigsten Erfolge angewendet und dargestellt von Dzierzon,
2 aufl. (without place of printing) 1849, p. 10G. Dzierzon expressed himself
in exactly the same way in a Supplement to the Theorie und Praxis, published
in 1852, p. 4 et seq.

42

PARTHENOGENESIS

fectly fertile : I say, perfectly fertile, or capable of producing
both sexes. For, to lay drone-eggs, according to my experience,
requires no fecundation at all. This is exactly the new and
peculiar point in my theory, which I at first only ventured to
put forward as a hypothesis, but which has since been com-
pletely confirmed. Three young queens with imperfect wings
have occurred during the past summer, and these, although,
from the imperfection of their wings, they could evidently never
have taken the fertilizing flight, and also on dissection proved
to be unfecundated, nevertheless laid drone-eggs*." — (< By this,
all the mysteries which we have hitherto vainly endeavoured to
unriddle, are completely solved. In the first place the enigma :
Why is it that many mothers — they may be either queens or
workers in their form — are only capable of propagating the
male sex or drones ? Because the former are either unfecun-
dated, or their fertility is exhausted ; the latter, on the other
hand, are incapable of fertilization."

" For I am firmly convinced that the egg-laying worker-bees,
which occur abnormally, are, from the want of a seminal recep-
tacle, just as little capable of being fertilized, as the young
queens from the want of sound wings. Moreover there is cer-
tainly no doubt, that by the peculiar tone of her wings the
queen allures the drones to her, and disposes them to copulation,
of which a worker is of course incapable. In the second place,
the before-mentioned power of the fertile queen to lay worker-
and drone-eggs at pleasure, is rendered very easy of explanation
by the fact, that the drone-eggs require no impregnation, but
bring the germ of life with them out of the ovary ; whilst other-
wise it would be inexplicable and incredible. Thus, as it has
already been shown that the ovaries are not impregnated, but
that the seminal receptacle is filled, during copulation, the queen
has it in her power to deposit an egg just as it comes from the
ovary and as the unfecundated mothers lay it ; or by the action
of the seminal receptacle, past which it must glide, to invest it

* [Here Hunter would perhaps have repeated his question, " But did they
hatch?" The particulars of the experiment by which Dzierzon knew that
drones came out of these eggs are not detailed ; the fact, however, is established
by the observations of Siebold and Leuckart, given in a subsequent part of the
work.— R. O.]

IN THE HONEY-BEE.

43

with a higher degree, a higher potency of fertility, and awaken
in it the germ of a more perfect being, namely a queen or a
worker-bee. This of course she does instinctively, induced by
the width of the cell to be furnished." — " For the production of
females in the bee-hive, therefore, more conditions and forces
are necessary than for the production of males or drones. Every
mother which is capable of producing worker-brood, can also
lay drone-eggs, but not inversely."

As was to be expected, these views upon the reproduction of
Bees called forth the most lively contradictions amongst the Bee-
keepers ; they were attacked with the most violent polemics in
the Bee-journal above mentioned, at the same time however that
most of the opponents, being destitute of any knowledge of the
anatomical structure of Bees, and of any insight into the phy-
siological import of the sexual functions in Insects, laid them-
selves open so miserably, that it must have been an easy matter
for Dzierzon to silence them ; but as it was almost entirely
dilettanti speaking to dilettanti, the dispute never came to an
end, the most incorrect, extraordinary and absurd assertions
upon the copulation, fecundation and oviposition of the Bees, &c.
being put forward in sober earnest as established truths, without
its being observed how completely such views, devised in the
fancy of a Bee-keeper, were destitute of anything like scientific
proof. Hence it was possible that, simultaneously with the
theory set up by Dzierzon, which its originator sought to sup-
port by important new evidence from time to time in the
Bienenzeitung, questions for investigation and reply were again
and again propounded in that Journal, upon which we must
have been long perfectly clear, since the most important points
in the reproduction of the Bees had been elucidated by Dzier-
zon's theory.

Thus in the different years of the Bienenzeitung up to the
most recent time, we may find the following questions put for-
ward as not satisfactorily answered, and the following points
referred to as doubtful by various Bee-keepers : namely, whether
the drones are really the male Bees ; whether the drones might
not have the care of the hatching of the eggs; whether the
drones are not truly abortions ; whether there are not also male
worker-bees; whether the queen is not perhaps fertilized by

44

PARTHENOGENESIS

caressing or by mere agitation ; whether the copulation between
the queen and a drone does not after all take place in the bee-
hive, and more of the same kind.

In opposition to these variously contradictory questions, I,
as Vice-president of the third meeting of German Bee-keepers,
held on the 2nd June, 1852, at Brieg in Silesia*, gave an
exposition of the anatomical relations of the three kinds of Bees,
the drones, the queen, and the workers, and called upon the
Bee-keepers present to express their objections and doubts
against the particular points of the theory established by Dzier-
zon. This was done on several sides ; Dzierzon, who was present
as President of the Society, defended his assertions with the
means which his abundant observations, conceived with a correct
understanding, furnished to his hand, whilst I came to his assist-
ance with my observations made with the dissecting needle and
the microscope, whenever reference was made to the different
anatomical relations and the signification of the internal and
external sexual organs of the Bees.

Although the majority of the Apiarians did not so quickly
drop their preconceived notions and incorrect views as to the
ceconomy, and especially the reproduction, of the Bees, yet a
constantly increasing number of voices was gradually raised in
the Bienenztitu.iig to confirm the correctness of individual points
in the theory of reproduction put forward by Dzierzon. People
began to interest themselves in the anatomical structure of the
Bees and of insects in general; they took notice of the know-
ledge obtained in recent times by the microscope, by which a
clearer view of the function of the male seminal fluid in the in-
terior of female insects had been gained. To strip everything
doubtful from those assertions in Dzierzon's theory which still
had too much of the garb of a hypothesis about them, and allow
them to appear as naked truths, those Apiarians, whose sole
object was to get at the truth, took care that various individual
Bees, the exact examination of whose condition might furnish
the right explanation of different doubtful points in Dzierzom's
theory, were handed over to practised entomotomists for a dis-
section and opinion. In this way this theory constantly gained
in firmness and form, and became strengthened in such a
* See the Bienenzeitung, Achter Jahrgang, \S52, p. 117-

IN TFIE HONEY-BEE.

45

manner that it may now claim to have taken root in the soil of
science, there to await a further development. Great merit, in
regard to the recognition of Dzierzon's theory, is due to Baron
von Berlepsch of Seebach, near Langensalza in Thuringia, as that
intelligent and experienced Apiarian neither shunned sacrifices,
time or trouble to obtain the most important information upon
the hotly contested questions relating to the reproduction of Bees
from his numerous Bee-colonies, which are extremely well arranged
for observation. In a series of Apistical letters Berlepsch* has
given a systematic exposition of the new theory of the reproduction
of the Bees, and supplied the individual positions with proofs sup-
ported upon the most arduous experiments, by which he has
shown himself to be a distinguished observer and acute naturalist.

It must also be mentioned that Dzierzon deserves to be cele-
brated as making an sera not only in the theory, but also in the
practice of Bee-keeping. He has, namely, given the Bee-hive an
arrangement, by which it becomes possible for the Bee-keeper
not only to follow the observation of the individual Bee-colonies
and to check the proceedings of their individual members or of
the foreign intruders in the most exact and certain manner, but
also to control and guide the entire ceconomy of the indi-
vidual hives from all sides. He hit upon the happy idea of
causing the Bees to build their combs from transverse sticks
placed loosely behind one another in the upper space of the
bee-hive, by which he was enabled as often as he pleased to
examine the whole of the combs in a hive one after the other,
the interior of the hive being rendered accessible by taking
away a moveable back or front wall, — as by this arrangement
each individual comb, clinging from beneath to the loose trans-
verse stick, can be taken out with this, examined on both sides,
and again suspended in its place without injury. By the help of
this ingenious arrangement f it had become possible for Dzierzon

* These Apistical letters are published in the Eichstadt Bienenzeitung for
the years 1853 and 1854, and form an extremely important document for our
knowledge of the history of reproduction in the Bees and Insects in general.

f As the lateral adhesion of the combs built down from the sticks frequently
rendered their removal difficult, Berlepsch tried to avoid this inconvenience in
a very ingenious way, by suspending in his hives, instead of the sticks, small
quadrangular frames, the vacuity of which the Bees fill up with their comb, by

46

PARTHENOGENESIS

not merely to trace what went on in a bee-hive from clay to day,
or from hour to hour, — he could even convince himself most
exactly, with his own eyes, at any time, as to what was taking
place in every individual cell of the different combs in his hives.
He was also enabled in this way to procure a knowledge of all
the proceedings of the workers in the interior of the hive between
the combs, and also to witness the doings of the queen bee.
These were all advantages which even the celebrated hives with
glass walls could not in the least present, as these latter bee-
hives only permitted the surface of a single comb which was
turned towards the glass to be inspected, but otherwise allowed
but a very small and extremely imperfect insight into the inte-
rior of a colony of Bees.

Dzierzon could give the most exact account of the condition
of his bee-hives. He knew the number and kind of the cells
which were daily or hourly supplied with eggs by the queen ;
he knew in what time the larvae in the eggs laid arrived at their
exclusion ; he was enabled to observe the gradual growth of the
larva; he could exactly ascertain what kind of food was fur-
nished to this or that larva by the workers ; he could acquire
the most positive information as to the time of pupation of a bee-
larva, as to the period of the escape of the Bee from the covered
cell, and as to the number and nature of the queen's cells; in
this way he was always informed in what condition the queen
governing a bee-hive was ; he could detect every disturbance,
every irregularity, which, induced by multifarious circumstances,
easily occurs in the well-ordered ceconomy of a hive, as quickly
as its cause.

What advantages this must have afforded to an Apiarian
endowed with such an acute and unprejudiced power of obser-
vation as Dzierzon, may be easily imagined. By this agency
the most important and instructive information regarding the
proceedings of a Bee-colony might flow in upon that acute
observer, and it could not but happen that at last the ex-
tremely remarkable and concealed process of the reproduction
of the Bees would be correctly penetrated by the eye of man.

which the removal and suspension of the combs are greatly facilitated, and
altogether such a convenient arrangement is given to the Dzierzon hive, that
nothing more remains to be desired.

IN THE HONEY-BEE.

47

But even for practice the Dzierzon bee-hives were of the
greatest importance, for Dzierzon could know exactly, at any-
time, and of any one of his bee-hives, how strongly it was
peopled, how industrious its inhabitants were, and what they
were occupied with. He could always inform himself whether the
number of workers was in proportion to that of the brood pro-
duced by the queen, whether the number or presence of drone-
larvae was or was not useful to the hive, whether the necessary
store of food was present, &c. With all this, the intelligent Bee-
keeper and possessor of Dzierzon hives, by the aid of which
a complete insight into the state of each household of Bees
might be attained, could exercise a directing and correcting
action, by adding the wanting number of necessary workers to
a hive which was poor in workers^ or taking away some of the
combs filled with eggs and brood from another scantily-peopled
hive, so as to lighten its work, and hanging them in an abun-
dantly-peopled hive for further care. The careful Bee-keeper
now knew from what hives he had to remove the combs filled
with drone-larvae which were either unnecessary or dangerous ;
he was enabled to save a hive, the inhabitants of which, although
otherwise industrious, threatened to become demoralized by the
loss of their queen, from this dangerous state of anarchy, by
taking care to replace this loss, where the Bees themselves
omitted to do so. In short, with the assistance of Dzierzon's
hives, an experienced and careful Bee-keeper may go to work
like an intelligent gardener, who, by cutting away the unneces-
sary shoots, and attending properly to the bud-bearing twigs,
prepares and supports his trees for the production of a rich
harvest of fruit*.

* Although it is several years since Dzierzon gave his " New Theory and
Practice of Bee-keeping" to the knowledge and use of the public through the
medium of the press, the advances made by Dzierzon in Bee-keeping have
only been able to make their way slowly and gradually in the circle of Bee-
keepers ; nay, it took still longer before the assertions of Dzierzon relating
to the reproduction of the Bees passed out of this circle to reach the ears of a
physiologist and naturalist. For this, Dzierzon himself is to blame ; this
Apiarian, otherwise so practical, hesitated to give his manuscript upon " Theory
and Practice" to a respectable bookseller for publication, but preferred making
known his inventions and discoveries in an extremely unpractical way, by
allowing his Neue Theorie und Praxis to appear at first as published by him*

48

PARTHENOGENESIS

In turning to the more exact exposition of Dzierzon's theory
of the reproduction of Bees, I give prominence to the most im-
portant points in the history of their propagation, upon the
establishment of which Dzierzon must have laid particular
stress, as a number of the proceedings in a bee-hive relating to
reproduction can only find their correct explanation and elucida-
dation if we maintain, that the young unfecundated queen never
copulates in the bee-hive, but always outside this, high up in the
air. I pass over the lively dispute which has been carried on
amongst Bee-keepers from time immemorial for the defence or
rejection of this point, and only refer to the fact that a queen
has never been surprised in the act of copulation within the
bee-hive by any Apiarian who has obtained an insight into the
interior of a hive by the employment of Dzierzon's hives. The
drones, as long as they remain in the hive, are always extremely
sluggish insects, which are not even roused from their quietude
and phlegm by the proximity of a queen desirous of copulation ;
on the other hand, when a warm, clear and still day has allured
them out into the open air, the sexual and copulative impulse

self, and afterwards disposing of it to a private individual living in a village in
Silesia for further distribution. Von Berlepsch justly complains of such a
proceeding (in the extra Supplement to No. 21 of the Eichstadt Bienenzeitung,
1852), as he, and with him many other Apiarians, were prevented by this
awkward and troublesome arrangement from an early adoption of the true
Dzierzon method of Bee-keeping ; for (as Berlepsch expresses himself upon the
Dzierzon hives) the invention of being able to take out the individual combs
suspended from little sticks, is undoubtedly the most practically important
one that has ever been made in Bee-keeping, and one which must necessarily
reform, that is to say, antiquate all previous methods, and to which alone
Dzierzon is indebted for the excellence of his breeds, and the almost complete
revelation of the natural history of Bees, their mode of life and of working.
After Dzierzon had sold his intellectual property into strange hands, which
withheld the most important part of his method, the right construction of the
true Dzierzon hives, from the public, he made another attempt to bring his
" Theory and Practice of Bee-keeping " into general notice, by printing in the
year 1854 the Bienenfreund aus Schlesien, a monthly journal of instruction
and entertainment for lovers of nature in general, and Bee-keepers in par-
ticular. Of this journal (published by Ad. Bander in Brieg) twenty-five
numbers have appeared up to this time ; but I fear that, from its inconvenient
form, and the somewhat diffuse style of the text, this means selected by
Dzierzon is not adapted to make the public acquainted and familiar with the
real essence of his theory and practice.

IN THE HONEY-BEE.

49

is awakened in the highest degree in these otherwise so sluggish
drones. They rove through the genial air high over their hives
with a loud humming to attract the attention of a queen, who
would be impelled to take her wedding-flight by the same
favourable weather. At any rate, very few of the many thousand
drones attain the longed-for happiness of being selected and
accepted by a queen for a husband, it being well known that
the number of female Bees is very small in proportion to the
great number of male individuals. But by means of this dispro-
portion, the few female Bees, on taking their wedding-flight, are
always sure of attaining their object, as from the number of
drones roving through the air with the same intent, it will not be
difficult for a queen to make choice of an agreeable consort.

That the copulation of the Bees takes place in the open air, is
certainly nothing remarkable, as we see so many other insects
perform the act of copulation whilst flying freely about in the
air. It is true that the copulative act is very quickly completed
by the Bees, and this is proper to all those insects in general,
which, with the Bees, belong to the order Hymenoptera ; whilst
the males and females of insects of other orders usually remain
for days closely united in copulation. For this reason it is one
of the rarest events for even the most observant entomologist to
surprise a pair of Hymenoptera in flagranti* . The Bee-keepers
therefore must not be surprised that the act of copulation in
Bees has hitherto been so little observed. However, it has acci-
dentally been seen now and then by human eyes, when a pair of
bees, united in the act of copulation, dashed down upon the
earth from the upper regions of the air. Such isolated observa-

* This is the reason why we find so many individual females or males
placed as separate species in no other order of the class of Insects as in the
Hymenoptera ; as in these insects the male and female individuals are often
quite differently coloured and marked, and as no trouble has been taken with
the rearing of them, as has been done with the Lepidoptera, it has hitherto
been impossible with many of these Hymenoptera to discover the sexes
belonging to the same species. Gravenhorst is therefore to be excused if he
has established a quantity of species of Ichneumons (in his Ichneumonologia
Europaa) which only consist of males or females. This certainly did not
happen from that desire which is carried so much too far by many entomo-
logists, of having the fame of giving a name to species which are new, but not
founded in nature.

E

50

PARTHENOGENESIS

tions, information upon which has also been given in the
Bienenzeitung*, are certainly sufficient evidence that the Bees
copulate outside the hive.

A still more convincing proof of the occurrence of this act
of copulation in the open air is furnished by the appearance
and behaviour of the fertilized queen on her return from her
wedding- flight. The completion of the coitus of such a queen
may betray itself even externally ; not only does the external
orifice of the sexual apparatus, which was kept closed before
the wedding-flight, stand open, but the torn male copulative
organs remain sticking in the vagina, and partly protrude from
it. In order to determine with certainty from its nature what
this foreign body, which had often been detected f in the
vagina of a queen on her return from the wedding-flight, really
was, Baron von Berlepsch forwarded to me for careful exami-
nation, on the 21st July 1853, one of these queens, from the
gaping sexual orifice of which definitely formed parts pro-
truded J. The results with which the exact anatomical and
microscopical examination of this queen has furnished me, have
been given by me in the Bienenzeitung By this analysis I

* See Bienenzeitung, 1845, p. 38 ; 1852, p. 188 ; 1853, pp. 108 & 174.

f Bienenzeitung, 1846, p. 95, and 1853, pp.43, 107 & 120.

X The letter from Von Berlepsch, which accompanied this queen, contained,
amongst other things, the following notes : — " Uninterruptedly occupied in
clearing up the natural history of the Honey- Bee, that is to say, in bringing
it to final conclusions, I succeeded, to-day, in impaling upon a pin, a queen
which had flown out to copulate, just as she was about to re-enter the hive.
The signs of copulation stand far out. In taking the liberty of sending you
this carcase, I have to beg that you will have the kindness to settle by dissec-
tion,— 1, if any, and what, parts of the drone occur in the royal vulva; and
2, what is the condition of the seminal receptacle. If there be parts of the
drone in the vulva, people will at last admit that the drones are the males,
that the copulation takes place outside the hive, and that it is absurd to
describe the drones as abortions, and seek the males amongst the worker-
bees. Moreover, if you find the seminal receptacle filled with semen, Dzier-
zon's hypothesis, according to which the ovary is not fertilized but the
seminal receptacle filled with male drone-semen by copulation, is raised into
evidence.'*

§ See Bienenzeitung, 1854, No. 20. p. 227, Zergliederung einer vom Begat-
tungsfiuge heimgekehrten Bienenkdnigin. Ein Sendschreiben an Herrn August
von Berlepsch in Seebach. I have at the same time made use of this letter to
explain to the Bee-keepers the anatomical conditions of the sexual organs of

IX THE HONEY-BEE.

51

was able to establish, that those definitely-formed parts in the
vagina of the queen were nothing but the torn copulative organs
of a male bee (drone). An intimate union of the two sexes of
Bees must therefore have taken place here. The remaining

the Bees, so that they might be at last convinced that the import of the drones,
queen, and workers in a colony of Bees could only be rightly estimated by
taking these conditions into consideration. That this was not superfluous,
was shown me by the thanks, repeatedly expressed in the Bienenzeitung, with
which my instruction was received by many friends of Bee-keeping. I thought
it my duty also to render this service to the Apiarians, when I remembered
what has been made known up to the present day as to the various erroneous
opinions asserted by Bee-keepers with regard to the history of reproduction in
the Bees (see supra, p. 2). To show into what wrong paths those Bee-keepers,
who, entirely mistaking the objects laid before them by nature, only wish to
pass off their own peculiar opinions, have got, I quote here literally from
Magerstedt's Pratkisches Bienenvater (oder Anleitung zur Kenatniss und Be-
handlung der Bienen, 1842, p. 68) what he teaches as the natural history of
Bees : — " The queen is the mother of all the worker-bees. Of these the greater
number are of the male, the smaller number of the female sex. She lays the
eggs of both kinds in the small narrow cells of the building. The care of the
brood is the duty both of the male and female worker-bees, but at the same
time they are assisted, for the furtherance of the work, by the sexless drones,
and for this reason the number of the drones is greatest at the time when the
most brood occurs. Their business is especially to warm the brood, and to
elevate the temperature of the hive during the time when the workers are
occupied out of doors. When, with a deficiency of nourishment and a diminu-
tion of the business of taking care of the brood, their presence is no longer
necessary, they are expelled. The queen, however, does not copulate. Her
first fertilizing flight agitates her ovary, and by this means she becomes capable
of laying fertile eggs." This book, tainted with such gross errors heaped one
upon another, has recently made its appearance in a third edition. Von
Berlepsch has assured me that he sent its author my letter, in order that he
might change his opinion. But now, in this third edition, which appeared
in 1856, we may read at p. 181 : — " The queen is the mother of all the worker-
bees ; a greater number of the workers is of the male than of the female sex.
Nature has distinguished both sexes externally. The queen is rendered
capable of reproduction, not by copulation, but by the agitation of her ovary,
and by its actions during the fertilizing flight, which is to be repeated several
times. The female bees are also rendered capable of laying eggs by flying
out, and by the agitation of their ovaries thus produced. From the eggs laid
by the female bees, drones are produced, and these being perfectly asexual,
do not cooperate in the business of reproduction, but in the care of the brood."
And also at p. 279 : — " Certainly they (the dronesj are not necessary for the
fertilization (of the queen)." What shall we say to such a complete ignoring
of the truth ?

E 2

52

PARTHENOGENESIS

behind of torn portions of the male sexual organs in the interior of
the female vagina, is, however, a circumstance which occurs not
unfrequently in other insects, especially in Beetles. With this
condition of the external sexual organs of the queen examined
bv me, the state of the internal generative organs also agreed
exactly, for the seminal receptacle (seminal vesicle), which is
emptv in all virgin female insects, was in this queen filled to
overflowing with spermatozoids (seminal filaments)*. This
queen therefore had returned to her hive certainly fertilized, and
would have possessed the power for a long time of effecting the

* [The experiment by which Hunter distinguished the seminal-sac from the
poison-sac in the complex female apparatus of the Queen-bee is ingenious and
characteristic : ■ To ascertain which was the poison, I dipped points of needles
into both bags \. and pricked the back of the hand ; and those punctures that
had the fluid from the first- described bag in them grew sore and inflamed,
while the others did not."— Phil. Trans.\792, p. 190.

He applied this anatomical knowledge to explain the impregnation of insects,
as follows : — " Insects, respecting the males, are of two kinds : one, where the
male lives through the winter as well as the female ; and the other where
evervmale of that species dies before the winter comes on; among which may
be considered, as a third, those where both male and female die in the same
year. Of the first I shall only give the common Fly as an instance ; of the
second I shall just mention all of the Bee tribe ; and the third may be illus-
trated in the Silk-worm. The mode of impregnation, in the first, is its being
continued uninterruptedly through the whole period of laying eggs ; while in
the second, the copulation is in store ; and in the third, the female lays up
bv the copulation a store of semen, although the male is alive." — Ibid. p. 185.

Hunter then proceeds to detail a series of experiments made to determine
the influence of the contents of the spermatheca of the female Silk-moth
upon the eggs, " which experiments," he says, " may be applied to the Bee,
and many other insects." Of these experiments it will suffice to cite the
following as illustrating his knowledge of that part of the mechanism of the
female organs in the Moth and Bee on which so much of the important facts
in the present work depends : —

" Experiment II. — I took a female Moth, as soon as she had escaped from
the pod, and kept her on a card till she began to lay. I then took females
that were fully impregnated before they began to lay, and dissected out that
bag which I supposed to be the receptacle of the male semen ; and, wetting a
camel-hair pencil with this matter, covered the ova as soon as they passed out
of the vagina. These ova were laid carefully on the clean card, and kept till
the ensuing season, when they all hatched at the same time with those natu-
rally impregnated. This proves that this bag is the receptacle for the semen,
and it graduallv decreases as the eggs are laid." — Phil. Trans. 1792, p. 188. —
R. 0.1

IN THE HONEY-BEE. 53

necessary fertilization of the eggs during oviposition with this
supply of male semen.

As in the act of copulation of the Bees, the penis of a drone
is completely protruded outwards, and as no particular muscular
apparatus exists for the extrusion of the penis, the circumstance
that the drones only copulate in flight has an important signifi-
cation, to which Leuckart* has already called attention ; during
the movement of the wings, the different air-sacs of the tracheal
system of the drone are filled with air, by which means these can
act by pressure in the interior of the body of the bee, upon the
neighbouring penis which is to be protruded.

After this single fecundation, a queen-bee can for a long time
lay male or female eggs at will ; for by the filling of her seminal
receptacle with male semen she has acquired the power of pro-
ducing female eggs, whilst before copulation and with an empty
seminal capsule, and therefore in the virgin state, she can only
lay male eggs. The second and most important point of the
new theory of the reproduction of Bees, is the proposition esta-
blished by Dzierzon, that, — All eggs which come to maturity in
the two ovaries of a queen-bee are only of one and the same kind,
which, when they are laid without coming in contact with the
male semen, become developed into male Bees, but, on the contrary,
when they are fertilized by male semen, produce female Bees.

Dzierzon therefore asserts that every egg laid without fer-
tilization by a queen-bee produces a drone, and that every
fertilized egg laid by her produces a worker or a queen, according
as the larva excluded therefrom is nourished with worker-food or
royal-food.

This proposition of Dzierzon's theory necessarily made the
greatest noise when it was first expressed, and requires above all
to be submitted to the closest examination. Before I undertake
this examination, I will only remark that one circumstance
speaks a priori in favour of this proposition of Dzierzon,
namely, that by adopting this proposition, every phaenomenon,
however remarkable, in the sexual existence of the Bees may be
easily explained. But as a time-honoured physiological law is
at once abolished by this proposition, namely, that an egg which
is to be developed into a male or female individual must always be
* See Bienenzeituny, 1855, p. 201.

54

PARTHENOGENESIS

fertilized by the male semen, the affair appears of sufficient im-
portance to be weighed and examined from all sides with the
utmost care. I have taken the trouble upon myself, and tested
Dzierzon's assertion with all the means at my command, by
which I have convinced mvself in the following: wav of its
correctness.

In the first place, I may appeal to the fact, that it is a general
occurrence amongst Insects, that the females, even when they
have not copulated, deposit their mature eggs without fecunda-
tion ; it is therefore nothing remarkable that a virgin queen
deposits eggs. But we must be astonished that these eggs,
although unfecundated, do not remain undeveloped : nay, what
is more, that only drones, or male Bees, are produced from such
eggs. As to the truth of this phenomenon, plenty of observa-
tions are adduced by the Apiarians, of which I bring forward,
only as the most convincing example, the drone- productiveness
of a virgin queen with imperfect wings. Every observant and ex-
perienced Bee-keeper knows the ill consequences introduced by
a queen-bee which has been excluded with crippled wings, and
which has acquired the dominion of a bee-hive. She finds her-
self prevented from undertaking the wedding-flight, but follows
the impulse to oviposition, and supplies worker-cells and drone-
cells indiscriminately with unfecundated eggs ; these arrive at
development, the larvae excluded from them are provided with
nourishment by the workers, they grow up, but all of the same
size and the same nature : for they are all drone-larvae, of which
those which have grown in worker-cells cannot find room in
these, and therefore the workers elevate their narrow cells by
subsequent additions, so as to obtain room, and in this way pro-
duce misshapen combs, or combs with the so-called crooked brood
[Buckelbrut).

A very interesting experiment was made by Berlepsch in
order to confirm the drone-productiveness of a virgin queen.
He contrived the exclusion of queens at the end of September
1654, and therefore at a time when there were no longer any
males ; he was lucky enough to keep one of them through the
winter, and this produced drone-offspring on the 2nd of March
in the following year, furnishing 1500 cells with crooked brood*.
* See Bienenzeitung. IS 55, No. 7- p. 76.

IN THE HONEY-BEE.

55

That this drone-bearing queen had really remained a virgin was
proved by the dissection, which Leuckart undertook at the re-
quest of Berlepsch*.

The true cause of such a drone-productiveness in a bee-hive,
however, could only be detected by an apiarian as acute and
endowed with such a distinguished power of observation as
Dzierzon, whilst up to this time the unfortunate occurrence of
an excess of drone-brood in a bee-hive has been quite differ-
ently and falsely understood by other Bee-keepers. They laid
no stress upon the fact that such a hive only contained drone-
brood, but they merely wondered that a hive governed by a queen
with crippled wings contained any brood at all ; and they en-
deavoured to explain this phenomenon by the supposition that
this unexpected brood could only be produced by a fertilized
queen. But as the queen from which this brood was derived
had been found to be crippled in the wings, they erred in respect
to the affair of copulation, and supposed that this crippled brood-
bearing queen was certainly fertilized, and that consequently the
act of copulation was effected by the queen-bee within the hive.
This erroneous conclusion of course brought in a number of
other errors with regard to the signification of the particular
Bee-individuals and their functions, by which a correct insight
into the process of reproduction in the Bees must always have
been disturbed.

Dzierzon alone did not allow himself to be diverted from the
right path in his observations; he maintained that the female
Bee can only return fertilized to her hive after the performance
of her wedding-flight. He did not, however, content himself
with this matter of experience ; he went further in his rational
way of investigating Bee-life ; he examined more closely the
egg-laying and drone-bearing queens, which according to his

* Leuckart found the state and contents of the seminal pouch of this queen
to be exactly of the same nature (see Bienenzeitung, 1855, p. 128) as I had
found in other virgin queens (see Germar's Zeitschrift fur die Entomol. 1843,
p. 374). The seminal receptacle in all these females never contained semen-
masses with their characteristic spermatozoids, but only a limpid fluid, desti-
tute of cells and granules, which is produced from the two appendicular glands
of the seminal capsule, and, as I suppose, serves the purpose of keeping the
semen transferred into the seminal capsule in a fresh state, and the spermato-
zoids active, and consequently capable of impregnation.

56

PARTHENOGENESIS

observations were to be regarded as virgins; he tore away
the apex of their abdomen, by which means he succeeded in
getting a sight of the seminal receptacle, which in a female Bee
is of the size of a pin's head. Dzierzon knew from experience,
that a fertilized Bee in the normal state contains a milk-white
seminal capsule, which when crushed gives issue to the milky
seminal fluid. He knew that the empty seminal capsule of a
newly excluded virgin queen is not milk-white, but limpid ; and
he convinced himself that in those drone-bearing queens with
crippled wings the seminal receptacle was limpid and empty of
semen, and consequently in the same state as the seminal cap-
sule of a virgin queen. I have spoken with Dzierzon upon these
observations ; and as, from my own microscopical examination,
I wras well acquainted with the state of the sexual organs of
virgin and fertilized queens, I was thus in a position to judge
quite safely, from the description which Dzierzon gave me of
his investigations, made without a microscope, that he had ac-
quired perfectly correct notions as to the difference in the con-
dition of the sexual organs of a virgin and fecundated female
Bee, and therefore could not well have deceived himself in this
respect*.

Moreover, I felt myself the less inclined to doubt the correct-
ness of these observations of Dzierzon's just reported, as I could
not but remember that, according to my own observations, the
females of certain Psychidce lay unfertilized eggs which are also
developed, but, inversely, instead of males produce nothing but
females. Dzierzon, however, by other observations furnished
me with evidence in favour of his proposition, that drones alone
are always produced from unfertilized Bees5 eggs when they are
developed, and that consequently, in order to obtain drone-brood,
it is not necessary that the queen-bee should fertilize the eggs
when laying them. As I have already mentioned (p. 39), it
happens now and then in a bee-hive, especially when it has lost

* Berlepsch has also seen drone-production and crooked combs caused in
the same way in bee-hives which were inhabited by a queen with crippled
wings, which had consequently remained without copulation. See (in the
Bienenzeitung, 1855, No. 7. p-75) the important and interesting letter addressed
to me by Berlepsch, in which he discusses the question, whether the drone-
eggs are fecundated.

IN THE HONEY-BEE.

57

its queen, that individual workers lay eggs. This phenomenon
has long been known to every experienced Bee-keeper ; nay, it
had already been observed, that only drones are developed from
these eggs laid by workers*; but it is only from the attentive
observer Dzierzon that we know why such egg-laying workers
are always the parents of drones, or, in other words, why only
drones are always developed from these eggs produced by
workers, if they attain to development. This phaenomenon stands
in the closest connexion with the drone-productiveness of the
virgin queen-bees already mentioned.

It was ascertained anatomically by Mademoiselle Jurine, that
the worker-bees are nothing but female Bees whose sexual or-
gans are abortedf. By careful dissection the ovarian tubes not
perfectly developed may be exhibited in all workers, connected
with an undeveloped oviduct. I have already shown in the year
1843, that in all workers, there is connected with this undeve-
loped oviduct, an appendage which perfectly represents the
seminal receptacle of the queens. On this appendage I could
discover the seminal duct, the seminal capsule, and the two
appendicular glands, with their common efferent duct in the
workers, but all these separate parts of the seminal receptacle
were in a very undeveloped state %.

In what follows, I will endeavour to explain by what cause
the ovarian tubes, which in the normally-formed workers always
remain empty, may become exceptionally filled with eggs in
certain workers. It is well known to Apiarians, that in hives
which have suddenly lost their queen, the workers, if they wish
to put themselves in possession of a new queen, select some
worker-cells furnished with an egg or a young larva, and enlarge
these into royal cells (queen's cradles), and that they do not
then bring up the larvae which are excluded from the eggs al-

* See Huber, XouvelJes Observations sur les Abeilles, p. 194. Even in the
time of Aristotle similar observations had been made, as appears from these
words: — "Dicimt indicio esse, qnod fucorum foetus innascantiir etiam, ubi
reges absint, apum autem non innascantur." See Aristotelis de Animalibus
Historic, lib. v. cap. 18 (ed. Schneider).

t See the works of Huber and Ratzeburg already quoted (p. 3).

% See my memoir upon the Receptaculum seminis of the female Hvmen-
optera. Gerraar's Zeitschrift fur die Entomol. bd. iv. p. 3~5.

58

PARTHENOGENESIS

ready laid in these former worker-cells, or which were found by
them already excluded in such cells, with the ordinary worker-
food, but furnish them with royal-food, as indeed all the eggs
deposited by a fertilized queen in worker-cells are of one kind,
namely female. But in order that the female sexual organs of
such a larva may acquire their development, the larva must
receive royal-food ; if, on the contrary, the female sexual organs
are to remain undeveloped for the advantage of the organs of
the worker-bee, destined for work, this object is attained by the
administration of worker-food. I leave it undecided in what
the distinction between the worker- and royal-food consists ;
for the Apiarians have hitherto been at variance, as to whether
the larvae of workers and queens received the same food, but the
latter in greater quantity, or whether the queen's food differed
from that of the workers not only in its quantity, but also in its
quality. From Leuckart's recent investigations*, however, it
appears that there really is a qualitative difference between
the two kinds of food. The larvae destined to become workers
only receive the paste prepared by the workers in their digestive
organs during the first days of their life, whilst in the latter days
of their larval existence they are fed with pollen and honey; the
queen-larvae, on the contrary, are supplied with the above paste
during their whole larval existence. Leuckartf found the first
traces of the internal genital organs in the female larvae of six
days old ; it is exactly at this time that the change of food takes
place in the worker-larvae, which up to this period are nourished
just like the queen-larvae with the same paste. In this way we
get an explanation of the circumstance which has been observed
by most experienced Apiarians, that a female larva does not re-
quire the usage of a queen from its earliest period in order to
become perfectly sexual, but that worker-larvae, even several
(six or seven) days old, may also be reared to queens, when
their narrow cells are subsequently enlarged, and they are abun-
dantly supplied with royal-paste, instead of with workers'- bread
(pollen and honey).

If then it is certain that a worker-bee or a queen may be
reared indifferently from every larva of a worker-cell derived

* See his Seebacher Studien in the Bienenzeitung, 1855, p. 209.
t See Leuckart, loc. cit. supra, p. 210.

IN THE HONEY-BEE.

59

from a fecundated queen, the case may probably occur in one
bee-hive or another, that, by some confusion or disturbance in
the regular distribution of the food, some of the royal-food falls
to the lot of one or several worker-larvae in the neighbourhood of
a queen's-cell, into which royal-food is carried, by which their
sexual organs are more or less developed. By this influence the
development of the female genitalia may have been abnormally
elevated in a worker, up to the power of laying true eggs*. Such
egg-laying workers, however, always remain unfecundated ; they
do not feel like perfect female Bees, and undertake no wedding-
flight ; which, indeed, would be of no use to them, as the deve-
lopment of their copulative and fecundative organs has not kept
pace with that of their ovaries and oviducts. The external
sexual organs, as well as the seminal receptacle, remain abortive
in these egg-laying workers, for which reason they are not in a
condition to copulate and receive fertilizing semen. They will
therefore only be able to lay unfecundated eggs, from which, if
they actually arrive at development, only male Bees are pro-
duced, no matter whether they were laid in worker-cells or drone-
cells. The cause of the production of an excess of drones and
crooked combs in a queenless hive is therefore, that as regards
the nature of her deposited eggs, an egg-laying worker-bee is in
exactly the same position as an egg-laying virgin queen, — both
can only be the parents of drones.

Why the egg- laying workers can only lay unfertilized eggs, I
have already explained in my letter to Baron von Berlepschf.
At that time, indeed, I had not been enabled to dissect an egg-
laying worker-bee ; so that the principal proof of the correctness

* Huber (Nouvelles Obs. sur les Abeilles, p. 202) was already acquainted
with these occurrences in the bee-hive, and endeavoured to explain them in
the same way.

[Hunter's observations had not extended his knowledge beyond the fol-
lowing point : — " As soon as a few combs are formed, the female Bee begins
laying of eggs. As far as I have been able to observe, the queen is the only
Bee that propagates, although it is asserted that the labourers do. Her first
eggs in the season are those which produce labourers, then the males, and
probably the queen. This is the progress in the "Wasp, Hornet, Humble-
bee, &c. However, it is asserted by Riem, that when a hive is deprived of a
queen, labourers lay eggs."— "On Bees," Phil Trans., 1/92, p. 152. — R. O.]

f See Bienenzeitung, 1854, p. 231.

60

PARTHENOGENESIS

of my views as to the drone-productiveness of the workers still
had to be obtained. This proof, Barun von Berlepsch has since
furnished by dissecting a worker-bee which was laying ^one-
eggs, and finding therein a small ovary with about eight pretty well
developed eggs, but no seminal receptacle*. He did not content
himself with this investigation of his own+. but in order to make
the unbelieving Apiarians more inclined to accept the truth, he
also called in the assistance of an entomotomist. At the request of
Berlepsch, Leuckart of Giessen dissected at Seebach two workers
taken in the act of laving eggs, of which, unfortunately, one
individual, as Leuckart reported i, was no longer in good con-
dition ; but on the other hand, in the second individual he was
able to prepare the sexual apparatus with its different parts in
connexion, and to recognize the egg-laying Bee from its con-
struction at the first glance. On the right side he found six,
and on the left five, ovarian tubes, with single mature eggs.
The single oviduct, as Leuckart said, was without appendages. In
the first-mentioned egg-laying worker also, Leuckart could detect
no seminal receptacle, although this structure is still distinctly
recognizable in the queens, even when the other entrails are
almost entirely dissolved by decomposition. I must here recall
the fact that, as I have already mentioned (p. 5/), the seminal
receptacle is not entirely wanting in the workers, but that it
remains undeveloped in them, and may be detected as a small
appendage to the oviduct by a close microscopical examination.
Leuckart overlooked this appendage in the egg-laying Bees
examined by him, but has convinced himself, as he himself
admits §, by subsequent investigations, of the presence of the
rudimentary seminal receptacle in worker-bees. At any rate,
it appears from the investigations of Berlepsch and Leuckart,
that, in the egg-laying workers dissected by them, the seminal
receptacle was not present in the same degree of development as

* See Bienenzeitung, 1S55, p. 7^. Huber also see his XoureHes Obserr.
p. 192 dissected some of these egg-laving workers, and found in one indivi-
dual eleven, and in the other four, mature eggs.

t That He it von Berlepsch has acquired the art of dissecting a Bee, I
had the opportunity of convincing myself last summer with my own eyes,
during my visit to Seebach. which will be mentioned further on.

% See Bienenzeitung. ISoo. p. 203.

§ Bienetizeitung. he. cit. p. 211.

IN THE HONEY-BEE.

CI

in the queen-bee, as in its perfectly developed state it is visible
even to the naked eye, of the size of a pin's head, and conse-
quently could not have escaped the notice of those two observers.

Another cause of drone-productiveness in a bee-hive may
also be explained consistently by Dzierzon's theory. Thus
in certain, but undoubtedly very rare cases, it happens that
fertilized queens in advanced age towards the end of their
vital activity become drone-bearing, after showing themselves
to be normal up to that period as regards the production of
drones, females, and workers ; normal fertilized queens, there-
fore, in course of time lose the faculty of producing workers and
females ; the brood deposited by such old queens can only be
reared to male bees, — certainly, according to Dzierzon's theory,
for the self-evident reason, that the store of semen in the seminal
receptacle of a fertilized queen is gradually exhausted. As a
queen only undertakes the wedding-flight once in her life, and
fertilizes many thousands of eggs destined for the worker-cells
for several consecutive years, with semen received by a single
act of copulation*, although only one or two spermatozoids of
the male semen are employed in the fecundation of one egg, yet
the seminal mass will at last be used up, and at the same time
the old queen will lose the faculty of laying the required number
of fertilized eggsf.

* According to a statement made to me by Dzierzon, a queen may acquire
the power of laying fertilized eggs for five years, by a single normally executed
copulation.

T Upon this subject I may allow the experienced Apiarian Von Berlepsch
to speak, as he has done in the Bienenzeitung (1855, p. 78) in the following
words : — " It is a fact, that queens, when their fertility is on the decline, lay
a greater or less number of drone-eggs in worker-cells amongst female eggs ;
nay, even with extremely fruitful queens, it by no means rarely happens,
that individual drones escape from worker-cells in the midst of workers.
How is this explicable except by Dzierzon's hypothesis, as even in this
case the queens evidently wish to lay, not male, but female eggs ? Lean-
ing upon Dzierzon's hypothesis, I conjecture that in queens whose fertility is
already on the wane, every egg can no longer be fertilized, because the recep-
tacle is no longer sufficiently filled with semen, but that in queens which are
still in the full power of their fertility, an egg which ought to be fertilized may
now and then glide past without fecundation ; a spermatozoon may not ad-
here, or may be lost again before it can penetrate through the micropyle into
the yelk."

62

PARTHENOGENESIS

From the circumstances hitherto described it will be evident,
how a queen which has not been fertilized, or an old queen or
egg-laying worker, must act injuriously upon a colony of Bees ;
they constantly cause confusion in a bee-hive, as they only
produce lazy drones, and cannot, by the production of new
workers, replace the loss of workers, to which every bee-hive is
exposed. On the other hand, a colony of Bees wrhich rejoices in
the possession of a vigorous,fertilized queen will thrive well, as the
drones, the workers, and the queens required for the emigration
of young swarms, are produced by her at the right time, and in
the proper proportions as to number, for which purpose the
workers prepare and arrange the necessary drone-cells, worker-
cells, and queen-cells.

Dzierzon's theory also includes the assertion that every nor-
mally organized and fertilized queen must at the same time
possess the power of laying male or female eggs at will, that is
to say, of leaving an egg unfertilized, or depositing it fecundated
at will, when engaged in laying her eggs.

The answer to the question, how a queen can know when she
has to lay a male or female egg, will be, that instinct will tell
her, and truly, at the moment when she pushes her abdomen
into a wide drone-cell, or the narrow cell of a worker, for the
purpose of laying an egg. The distinction of the wider and
narrower cells will certainly be felt out by a normal queen with
her abdomen, and by this sensation she will know, that she
must fertilize the egg to be deposited in a narrow cell, whilst
she has to lay down the egg without fecundation in a wide one.
By the peculiar texture of an incomplete royal-cell too, a normal
queen will be instinctively induced to fertilize the egg to be
deposited in it. By this means Dzierzon might have explained
that phsenomenon in the bee-hive which has always excited
astonishment as a wonderful mystery, namely, that faculty
possessed by the normal queen of furnishing the drone-cells,
worker- cells, and queen-cells of the combs, which are arranged in
different number and order in every bee-hive, with the right eggs.
It would certainly still remain to be proved, from the organi-
zation and arrangement of the separate sections of the female
sexual organs, that it really was possible for a fertilized queen,
by the presence of decidedly voluntary muscles, to retain the

IN THE HONEY-BEE.

63

semen in the seminal receptacle or evacuate it at will. From
the investigations above referred to (p. 4) which I made upon
fertilized female insects, it appears that by the copulation of
Insects the ovaries are not fecundated, but that the seminal re-
ceptacle is filled with semen, and that the fecundation of the
egg only takes place during oviposition at the moment when the
egg to be laid slips by the orifice of the seminal receptacle in
the oviduct. With regard to this I may refer to those female
insects, which, after the completion of copulation, survive their
males in the autumn, hybernate with the ovaries imperfectly
developed, and only lay fertilized eggs capable of development
in the following spring, after their ovaries have become filled
with mature eggs*. Such females, therefore, preserve the male
semen received during copulation in their seminal receptacle,
keep it fresh, probably by the aid of the secretion of the appen-
dicular glands of the seminal capsule, and evacuate it at pleasure
when required during the act of laying. For this purpose par-
ticular voluntary muscles do really exist ; I have observed them
in the vicinity of the exterior of the seminal capsule in many
female Beetles f. In the immediate vicinity of the seminal re-
ceptacle of female Bees also, I have seen voluntary muscles,
without, however, being able to state with certainty what definite
functions they have to perform. From this, the possibility of a
voluntary evacuation of semen from the seminal receptacle of
fecundated female insects could certainly not be denied, espe-
cially as the voluntary deposition of male and female eggs by a
queen-bee may be proved by the brood produced from her.
After I had called the attention of Von Berlepsch to the exist-
ence of voluntary muscles at the seminal receptacle, he expressed
himself upon this point in the following way J : — " Probably the
queen has the faculty of closing the orifice of the receptacle at
pleasure, perhaps by the contraction of the whole vesicular mem-
brane, or even that of removing and somewhat retracting the

* See upon this point my observations on hybernated fertilized female
Wasps and Gnats, in Wiegmann's Archiv fur Naturgeschichte, 1839, bd. i.
p. 107, and in Germar's Zeitschrift fur die Entomologie, bd. ii. 1840, p. 443.

t See my investigations Ueber die Spermatozoen in den befruchteten Inselcten-
Weibchen, in Miiller's Archiv, 1837, p. 398. tab. 20. figs. 1 & 2 g, & p. 423.

X Bienenzeitung, 1855, No. 7- p- 77.

64

PARTHENOGENESIS

whole receptacle sideways from the tube of the oviduct into
which it opens, so that those eggs which she wishes to deposit
in male cells may glide past untouched by the semen."

The power of a fertilized queen to lay male or female eggs
at pleasure, may also be proved by the following experiment. In
a Dzierzon hive we may. to a certain extent, compel a fertilized
queen to lay male or female eggs. The construction of one of
these hives permits the nature of the combs prepared in it by
the workers to be closely inspected : if the workers of a hive
furnished with a normal queen prepare too many drone-cells,
which we may perhaps not wish to have, or if the hive requires
more workers, we may remove the drone-combs, whose cells the
queen would have shortly supplied with male, that is to say,
unfertilized eggs, and instead of these suspend combs with empty
worker-cells ; the queen will furnish these combs also with eggs,
and indeed, to correspond with the nature of the cells, with
female or fertilized eggs, from which the workers may rear their
like. In the summer we may induce the queens of populous
hives to lay drone-eggs, if we suspend an empty drone-comb in
the midst of the hive. From this it follows that the intelligent
Bee-keeper has it in his own hands in what direction he will
turn the activity of this or that colony of Bees, and that by
suitable assistance he may prevent the disorganization and de-
moralization of a bee-hive.

Before I turn to the strictly scientific proofs which I have
still to furnish, in order to give permanence to the view upon
the reproduction of the Bees put forward by Dzierzon onlv as
a hypothesis, and raise it to the rank of a theory, so that it
may take its proper place in the history of animal development,
I will here cite a few more empirical proofs, by which alone the
correctness of Dzierzon's theory would be convincingly shown,
if its importance did not require still more impressive facts for
its establishment.

I must not omit to mention that Dzierzon himself, after calling
a number of opponents into the field by the promulgation of
his new theory, and after all possible imaginable objections had
been raised from the most various sides against its correct-
ness, began to doubt the perfect tenability of his theory. Not-
withstanding that very recently Dzierzon expresses himself

IN THE HONEY-BKE.

65

with peculiar reserve and caution upon certain points of his
theory*, other experienced Apiarians still held firmly to it, as
after it had once become perfectly familiar to them, by its
assistance ever}' occurrence in a bee-hive, however unexpected
or apparently strange, was instantly understood by them.

Above all we must here mention Herr von Berlepsch, who
has set himself the task of testing Dzierzon's theory in every
direction, with his abundance of bee-hives. His establishment
of Bees, which is most carefully attended to, and kept in the
most exemplary order, also offers quite uniquely in its kind, by
the disposition, arrangement and mass of its materials, the best
and most certain opportunity of testing and answering those
questions relating to Bee-life raised by Dzierzon.

The following extremely interesting experiments were made
by Berlepsch, which must again convert Dzierzon himself, since
he appears to have become a doubter of his own theory.

In May 1854 Berlepsch caught an old fertile queen f, and
confined her in a small queen's cage, in order to incorporate her
with a new colony of Bees after its establishment. She was in
the normal state, and up to that time had produced the neces-
sary drones and workers. Berlepsch gives the following account
of this queen : — " As I was closing the lid (of the queen's cage),
which ran in a groove, I pinched the queen so strongly at the
apex of the abdomen, that she contracted the whole abdomen
like a bee that has been stung, and allowed it to drag after her.
I thought at first that she was lost, but as she was still living
an hour afterwards, and sitting again extended and quiet, I gave
her back to her people. She laid, as before, thousands of eggs,
but from all these nothing but drones were henceforward deve-
loped. If 1 had only dissected this queen as soon as I became
aware of her drone-productiveness, I should at least have seen
whether the (seminal) vesicle was still in existence and normally
filled. But I delayed the dissection, and when at length I
wished to undertake it, the queen was gone. This certainly
very remarkable occurrence, which speaks loudly in favour of
Dzierzon's hypothesis of the unfecundated state of all male eggs,

* See his Bienenfreund aus Schlesien, 1854, No. 8. p. 64.
t See the letter addressed to me by Berlepsch in the Bienenzeitung , 1855,
Xo. 7- p. 78.

F

66

PARTHENOGENESIS

was communicated by me privately to President Busch for his
opinion, as I could not then form any definite opinion for my-
self, not knowing with certainty that the vesicle is the recepta-
culum seminis, and the white slime (its contents) the sperma
virile. Busch, however, was also unable to form an opinion ;
my servant Giinther on the contrary thought, that perhaps the
receptaculum had been crushed and destroyed. This, however,
I regard as extremely improbable, as the crushing of the recep-
tacle, which is generally very firm, between the soft surrounding
parts of the body of the queen, without quickly leading to the
death of the latter herself, is scarcely possible ; I believe, there-
fore, that it was only that the organs which may act in opening
and closing the orifice, or in retracting and advancing the re-
ceptacle, were lamed, stiffened," &c.

If I am to express my opinion upon this interesting case,
I suppose that by the pinching of the abdomen the seminal re-
ceptacle of the queen, filled with semen, was torn away from the
oviduct at its opening point, by which the queen, thus injured,
was no longer enabled to fertilize her eggs during deposition,
and therefore could only lay unfertilized and consequently male
eggs.

Berlepsch reports as follows* upon another experiment con-
firmatory of Dzierzon's principal point, which he made in con-
sequence of studying J. Mulleins Physiologie des Menschen :
" Now only did I obtain a full conviction of the existence of
the spermatozoa ; and when I read in the above-mentioned work
(bd. ii. p. 636) that high and loiv temperatures cause the move-
ments of the spermatozoa to cease, I thought to myself : Now you
have the complete explanation of Dzierzon's casef; and if it be
true that in Apis mellifica the male eggs regularly develope
themselves spontaneously into males, but are only converted
into female eggs by the fecundation of the spermatozoa, every
normally fruitful queen must cease to lay female eggs, from the
moment when we succeed in rendering the spermatozoa motion-

* See his letter quoted above, p. 61.

f Berlepsch here refers to the case cominunicated by Dzierzon (Bienai-
zeitung, 1854, p. 252. 2), that a queen which had been frozen for a long time,
after being again brought to life by warmth, only laid male eggs, whilst pre-
viously she had also laid female eggs.

IN THE HONEY-BEE.

67

less (killing them) without destroying the mother herself. At
the end of June 1854, therefore, I took three very fruitful queens,
imprisoned each of them in a queen's cage, went to Miihlhausen
and placed the cages in the ice-cellar of an inn-keeper who was
a friend of mine. There I left them for about thirty-six hours.
The queens were of course completely benumbed, regularly
covered with hoar frost, and when I returned with them to
Seebach, I exposed them to the sun, which was just rising. For
a long time none of them stirred ; at last, towards seven o'clock,
I observed movements of the feet in one of them. By means
of a fine bit of wood I put a little honey upon her proboscis, and
in ten or twelve minutes more, she had again returned to life.
The two others on the contrary were dead. This appeared very
remarkable to me, as even worker-bees, whose vitality, however,
is very much weaker than that of the queens, generally survive
such a short freezing ; and the only reason I can find for it, is,
that the temperature of the ice-cellar was too low, and therefore
the queens were too much penetrated by the frost, if the circum-
stance that the queens were too heavy with eggs, and therefore
less able than at other times to bear external injurious influences
upon their bodies, may not have cooperated to produce death.
I returned the revived queen to her people. She laid, as before,
thousands of eggs, but from all of them only males were evolved.
When I subsequently examined the semen, I found it less con-
sistent and with a yellowish tinge."

From this extremely interesting experiment, it follows evi-
dently that the male eggs of the Bees require no fertilization ;
the spermatozoids which this queen, exposed to such an intense
cold, contained in her seminal receptacle, were certainly be-
numbed, and did not again become capable of movement after
the thawing ; so that therefore this queen could only have laid
unfecundated eggs ; for even if she had emptied the contents of
her seminal receptacle over the eggs when laying them, in order
to fertilize them, the numbed spermatozoids would have remained
incapable of action.

A third empirical proof, by which the principal point of
Dzierzon's theory of reproduction is supported, is furnished by
the phaenomena which maybe observed in the production of mules
amongst Bees. Attention has only been directed to the pro-

f 2

6S

PARTHENOGENESIS

ducticn of hybrid Bees at a very recent period, since the Italian
race of Bees has been introduced into Germany by Dzierzon
and Berlepsch. The so-called Italian Bees form no separate
species, but must only be regarded as a variety of the Apis
melUfica. These Italian Bees are distinguished at the first
glance by the leather-yellow colour of their abdomen from the
unicolorous blackish-brown German Bees. In the females and
workers of the Italian race, the first, second and third abdominal
segments appear of a rusty -yellow colour colore rvfo-ferrug'xneo)
and margined with black : this black margin is very narrow on
the first segment, broader on the second, and broadest on the
third. The Italian drones have the middle of the hinder margin
of the second, third and fourth, and often that of the fifth
abdominal segment broadly rusty-yellow, by which the blackish-
brown abdomen of these drones appears to be furnished on the
back with from three to four rusty-brown transverse bands, of
which the first is the broadest. The German drones, on the
contrary, have the abdominal segments only narrowly margined
with rusty-yellow*. According to the statements of Dzierzon

* This variety of Apis melltfca has already been tor an extraordinary
length of time indigenous in Italy and the South of Europe generally, for
Virgil, and before him Aristotle, mention these rusty -yellow Bees in their
descriptions of the ceconomy of Bees. But unicolorous dark Bees must also
have occurred constantly amongst the variegated or rusty-yellow spotted
Bees, as both authors also speak of black Bees. In Aristotle's De Ani-
malibus Historic, lib. v. cap. IS. 2, we find. — " Re gum autem genera duo:
pnestanrior rufus : alter niger et varius magis." And further, lib. v. cap. 19. 1,
™ In genere apum pra?sranrissima quse parva. rotunda, varia : alteram genus
est oblongum et vespa? Anthrena? simile: tertium furem vocant : niger is.
alvo lata. Quartus fuscus. omnium maximus. sine aculeo. ignavus." The
verses of Virgil, in which Georyicon. lib. iv. 91 he declares the variegated
Bees to be more valuable than the black ones, are well known : —

Alter erit maculis auro squalentibus ardens :
Nam duo sunt genera : hie melior. insignis et ore.
Et rutiiis clarus squamis ; ille horridus alter
Desidia, latamque trahens inglorius alvum.
Ut bina? re gum facies. ita corpora plebis.
Xamque aha? turpes horrent : ceu pulvere ab alto
Quum venit. et sicco terrain sptut ore viator,
Aridus ; elucent alia?, et fulgore coruscant,
Ardentes auro et paribus lita corpora guttis.
Ha?c potior suboles."

IX THE HONEY-BEE.

and Berlepsch, who have done especial service to the breeding
and diffusion of the Italian Bees in Germany*, these golden-
yellow Bees are not only more beautiful, but also more indus-

The statements also which Varro and Columella have made upon Bee-keeping,
show that in Italy the gold-coloured or variegated Bees and the unicolorous
blackish-brown Bees occur together. See Scriptorum rei rustics veterum la-
tinorum (ed. Schneider), torn. i. p. 316. Varronis lib. hi. cap. 16: — "Ut qui-
dam dicunt, tria genera cum sint ducum in apibus, niger, ruber, varius, ut
Menecrates scribit duo, niger et varius : qui ita, melior ; ut expediat mellario,
cum duo sint eadem alvo, interficere nigrum, quern scit cum altero rege esse
seditiosum, et corrumpere alvum, quod fuget, aut cum rnultitudine fugetur.
De reliquis apibus optima est parva, varia, rotunda." Columella (lib. ix.
cap. hi. op. cit. supra, torn. ii. P. i. p. 437) in the description of the Bees
refers to the statements of Aristotle and Virgil, and says of the queens
(cap. x. op. cit. p. 453), — " Sunt autem hi reges majores paulo et oblongi
magis quam cseterae apes, rectioribus cruribus, sed minus amplis pinnis,
pulchri coloris et nitidi, levesque ac sine pilo, sine spiculo, nisi quis forte
pleniorem quasi capillum, quern in ventre gerunt, aculeum putet, quo et ipso
tamen ad nocendum non utuntur. Quidam etiam infusci atque hirsuti reperi-
untur, quorum pro habitu damnabis ingenium." Therefore, even amongst the
Romans, the variegated and golden-yellow Bees were more highly valued than
the unicolorous blackish-brown race. That this rusty-yellow variety of the
Honey-Bee is at present very widely diffused in Italy, appears from the descrip-
tion which Spinola {Insectorum Ligurice species novce aut rariores, torn. i.
1806, p. 35) has given of a Piedmontese Honey-bee. This Bee, furnished by
Spinola with the name of Apis ligustica, agrees exactly, according to the
description, with the rusty-yellow Bees recently introduced amongst us from
Italy. Two individuals of the Apis ligustica, captured near Bellinzona and
Sesto Calende on the Lago Maggiore, which I have been able to compare
here with some Italian Bees of the true race bred in Seebach, I cannot re-
cognize as a separate species, but only as a rusty-yellow variety of the Apis
mellijica, the unicolorous dark form of which, according to Spinola's own
statements {op. cit. p. 133), also occurs, although rarely, in Piedmont. The
aurora-coloured Bees mentioned by Delia Rocca (Traite complet sur les
Abeilles, 17^0, torn. ii. p. 142), and said to have been introduced into France
from Holland or Flanders, may have belonged to the same Italian variety.
The Egyptian Honey-bee also, described by Latreille {Annates du Museum,
torn. v. 1804, p. 171) under the name of Apis fasciata, is probably nothing
but this southern rusty-yellow variety of the Apis mellijica, especially as
Latreille himself admits that this Egyptian hive-bee agreed exactly with a
kind of Honey-bee taken near Genoa.

* Herr von Balden stein of Graubiindten has the merit of having first
directed attention to the Italian Bees as an object adapted for experiment
^see the Bienenzeitung, 1848, p. 26). He had got an Italian bee-hive con-

70

PARTHENOGENESIS

trious and better-tempered than the German Bees. These
latter properties are also the cause of the Italian Bees having
become so much liked amongst us, and of so great a demand
having recently arisen for them, so that Berlepsch found him-
self under the necessity of declaring publicly*, that " If the
Italian good-tempered, industrious race, with its beautiful colour
is to be kept pure and stereotyped, perhaps even improved
Dzierzon and I must be left in peace for at least one summer"

It is a well-known fact, that by the crossing of different races
of a species of animal, hybrid forms are produced, which unite
in various ways certain characters of the two individuals of
different races which were employed for the production of such
race-hybrids. It was natural to suppose that in the Bees, the
production of such race-hybrids must be combined with very

veyed over the mountains, in order to make use of the difference of colour
which occurs between the rusty-yellow Italian Bees and the unicolorous dark
Swiss and German Bees in his observations. In the following year he per-
ceived that his Italian Bees degenerated in the mother-hive, a part of the new
brood being quite Italian ; whilst another part, on the contrary, appeared more
or less like the Swriss Bees. From this phenomenon Baldenstein correctly
concluded that the young Italian mother-bees must have copulated with a
Swiss male bee, and certainly outside the hive : this production of hybrids
would not have taken place if the young Italian queens had copulated in the
mother-hive, where they met with a sufficiency of true Italian drones. Balden-
stein further mentions (Bienenzeitung, 1851, p. 81) that those Italian mother-
bees, when he received them, were already four years old, and lived with him
for three years more, therefore in all seven years ; they always produced true
Italian Bees, by which it is proved that these queens required no fresh copula-
tion after the first one.

Incited by these interesting observations of Baldenstein's (see also the
Bienenzeitung, 1853, p. 11), Dzierzon in February 1853 procured a bee-hive
of the true Italian race (see Bienenzeitung, 1852, p. 204 ; and 1853, p. 40)
from Madame Adele von Prollius, a zealous Apiarian at Mira near Venice,
from which stock at Carlsmarkt (in Silesia) the other German Bee-keepers
might be provided with Italian Bees, by the observations of which such im-
portant scientific results have been obtained. For the various reports of the
breeding of Italian Bees, see the Bienenzeitung for the years 1854 and 1855,
and also the essay in that Journal for 1856, p. 1, in which Dzierzon discusses
the question, — Is the Italian kind of Bee found by experience to be of the
same importance for practice as for theory ? And, above all, read the im-
portant communications of Berlepsch upon the Italian Bees (Bienenzeitung,
1856, p. 3). * Bienenzeitung, 1856, p. 6.

IN THE HONEY-BEE.

71

peculiar modifications. If Dzierzon's theory proved correct, we
might beforehand expect that by the copulation of a unicolorous
blackish-brown German and a reddish- brown Italian Bee, the
mixture of the two races would only be expressed in the hybrid
females and workers ; but not in the drones, which, as pro-
ceeding from unfecundated eggs, must remain purely German
or purely Italian, according as the queen selected for the pro-
duction of hybrids belonged to the German or Italian race. In
fact, the expectations of the Apiarians were not disappointed.
It is true that in these crossings of the races many remarkable
occurrences, such as also happen, contrary to expectation, in the
crossing of our larger domestic animals, were still necessarily left
unexplained. According to Berlepsch's observations*, 1. many
Italian mothers produce partly black and partly variegated
Bees under all circumstances, that is to say, whether they have
been fecundated by an Italian or a German drone ; 2. many
Italian mothers produce only variegated Bees when they are
fertilized by an Italian drone, but variegated and black ones
mixed when the fertilization is effected by a German drone ;
and 3. many Italian mothers produce only variegated Bees
under all circumstances, that is to say, whether they are fer-
tilized by an Italian or German drone. Such true Italian
queens, adds Berlepsch, produce Italian Bees from the very
first, when fertilized by Italian drones ; but, on the contrary,
when fertilized by a German drone, they also produce German
Bees at first, for a longer or shorter time.

Here I must insist upon the fact, that these statements of Von
Berlepsch only refer to the production of workers and female
Bees, but by no means to drones. He endeavoured to explain
these surprising and singular facts, which reposed upon two years5
experience, in the following manner. He refers to the existence
of the appendicular gland so intimately connected with the semi-
nal receptacle, to which I had even in the year 1837t ascribed

* See the Bienenzeitung, 1856, p. 5.

t See my memoir Ueber die Spermatozoen in den befruchteten Insekten-
Weibchen (Miiller's Archiv, 1837, p. 398). In this place I have said of the
Glandula appendicularis, — " This organ probably serves for the secretion of a
particular fluid, which is poured into the seminal receptacle and keeps the
spermatozoa which remain here for a long time, alive." See also Germar's
Zeitschrift fur die Entomol. 1843, p. 368.

n

PARTHENOGENESIS

the office of preserving by its secretion the seminal mass remain-
ing for months in the seminal capsule, in a fresh state. Berlepsch,
starting from this view, now thought, that the maternal liquor
of the appendicular gland constantly penetrating (into the semi-
nal receptacle) gradually permeates the spermatozoa to such an
extent that their paternal elements are overpowered by the mater-
nal ones. If the mother-bee is of pure Italian blood, none but
variegated Bees must be produced from her fertilized eggs, as
soon as the spermatozoa derived from a German drone are suffi-
ciently permeated : but, on the contrary, if the mother be not
purely Italian, black Bees will always remain. This conjecture,
which I only quote here for the present as a conjecture, without
saying anything for or against it, Berlepsch also endeavoured to
support by the behaviour of a German queen, which, being fer-
tilized by an Italian drone, produced last year variegated Bees
amongst the black, but this year only black Bees.

In all these observations with reference to the propagation
and multiplication of the Italian race of Bees, the brood of drones
always turned out purely Italian, or purely German, even when
crossings occurred between the German and Italian Bees, accord-
ing as the queen subjected to crossing belonged to the Italian or
German race. But in order to attain certainty with regard to
these phenomena, the observations to be made for this purpose
must be performed with the greatest care. The observations
will have to be made only with individuals of perfectly pure race,
which will not always be obtained with ease and certainty, since
the breeding of the Italian swarms side by side with the German
bee-hives is already carried on amongst us to a very great extent.
How difficult it may be to find a perfectly genuine and pure
queen for such experiments, is shown by the mixtures of the two
races of Bees in question, observed by Berlepsch and already
referred to. I can therefore lay no very great stress upon an
observation which Dzierzon made upon an Italian queen, and
which, as I have already indicated (p. 64), has made this cautious
Apiarian doubtful of his own theory. This isolated case, in
which, moreover, some circumstance might probably have re-
mained unnoticed, cannot overthrow a proposition, the correct-
ness of which has been confirmed in so striking a manner by a
number of other observations. How Dzierzon was surprised by

IN THE HONEY-BEE.

73

some such disturbing accident appears from his own statement,
which I will give here literally, in order to show that Dzierzon
is not one of those who cannot be led away from a preconceived
opinion, whether it be right or wrong. His words* are as follow : —
" Continued observations of the hybrid hives also must be no
less adapted to raise the veil more and more, to penetrate into
the obscurity and finally bring the mysterious truth to light. If
the drone-egg does not require fertilization, Italian mothers must
always produce Italian drones, and German mothers German
drones, even when they have been fertilized by drones of the
other race. The Silesian Apiarian {Bienenfreund) possesses
hybrid hives of both kinds, and did not permit any want of ob-
servations so far as the limited time enabled him to make them,
but he met with new unsolvable riddles. The Italian hybrid-
mothers have throughout completely confirmed the supposition
and produced the most beautiful Italian drones, one almost more
beautiful than the genuine stocks, the maternal stock itself. Of
two German hybrid hives, one also produced only the ordinary
black drones ; the other the same, but unexpectedly amongst
these a few appeared which glittered like gold, and were yellower
than any single bee even in the genuine Italian hives. It cer-
tainly was possible that even here a beautiful Italian amongst the
workers, of which a portion had the colour of the indigenous Bees,
and another portion that of the Italians, might have laid some
eggs, from which the few yellow drones might have been pro-
duced. Nevertheless the Silesian Apiarian is not particularly
inclined to explain the phenomenon in this way, so as not to ex-
pose himself to the suspicion that only a predilection for his hy-
pothesis led him to have recourse to this explanation, as in point
of fact the deposition of eggs by worker-bees when a queen is
present, is an exceptional occurrence of the rarest kind. Although
the vesicle filled with semen does not implant the vital germ for
the drone in the egg, may not a peculiar emanation from it never-
theless act in determining the kind and colour?"

Dzierzon is certainly in the wrong, when, for the sake of this
one observation which disturbs him, and in order to explain
it, he again calls in the aid of the long-overthrown hypothesis of
the action of an aura seminalis. Von Berlepsch has taken the
* See the Bienenfreund aus Schlesien, No. 8, 1854, p. 63.

74

PARTHENOGENESIS

trouble to invalidate this case detailed by Dzierzon, which is said
to speak against his own theory. He very justly observes*, that
in the preceding, Dzierzon has not established the fact that those
few golden drones were actually produced by the queen, and not
by a very fine egg-laying Italian worker (as the half of the workers
in this hive consisted of these); for although the presence of an
egg-laying worker together with a queen is a case of the very
rarest occurrence, yet it can be proved that such exceptions do
occur. Berlepsch also points out with reason, that Dzierzon
was never perfectly certain on the point whether the queen, in
whose hive he observed the remarkable yellow drones, was by
birth of true German race, or produced from hybrid brood.
Dzierzon himself adds the warning to the statement of his casef,
that in such observations great caution is necessary to avoid
erroneous conclusions, as on such occasions we must be perfectly
sure that the queen belongs by birth to the right race ; for if she
has been produced from hybrid brood, it is impossible for her
to produce even pure drones, but she produces half-Italian and
half-German drones. However, I regarded this doubt, which had
been raised in Dzierzon with regard to his own theory and by
his own observations, as a sufficient reason for getting further in-
formation from Herr von Berlepsch, who had obtained great
experience in breeding Italian Bees for the last two years, with
regard to the real truth in the production of hybrids taking place
between Italian and German Bees. On the 2nd March of last
year (1856) he replied to my questions put to him for this purpose,
in the following manner. In the first place he referred to his
observations already published in the BienenzeitungX, where he
says : — " All queens which are of a beautiful yellow externally
only produce Italian drones, even when they produce partly Italian
and partly German workers. A German mother, which was
fertilized by an Italian drone, produced German and Italian
workers, but only German di^ones. When on the contrary the
mother is not of a fine yellow, — when she has traces of black blood
in her, the drones also come forth mixed, whether the mother be
fertilized by a German or Italian male : of course because the

* See the Bienenzeitung, 1855, p. 79.

t See the Bienenfreund cms Schlesien, ut cit. supra, p. 64.

X For the year 1856, p. 6.

IN THE HONEY-BEE.

75

males only take after the mother." To this Von Berlepsch added
the following commentary in his letter : — " An Italian queen fer-
tilized by a German drone, or a German queen by an Italian
drone, constantly (only one exception has occurred to me) pro-
duces females (workers, queens) of three different colours : a. True
Italians, that is to say, as yellow and banded as the female de-
scendants of Italian queens, which were also fecundated by Italian
drones ; b. True Germans, and c. Mongrels. With many mothers,
the Italian, and with many the German descendants predominate;
but the mongrels, which, as regards colour, are intermediate be -
tween the Germans and Italians, are always in the minority, and
indeed in the greatest minority, for in many hives we rarely see
a mongrel, and in many none at all. Now as the queens are only
workers, otherwise, that is to say, further developed, the same
conditions occur in them also, and in hybrid mothers the colour
of the royal descendants depends upon the egg. If the egg
would have given a true Italian worker, it also furnishes a
genuine Italian queen, &c. The males without exception follow
the mother as regards colour, and during the last summer I was
unable to discover with hybrid mothers even a single male which
resembled its father, in spite of the most careful observation and
the closest examination."

After such important empirical facts, derived from the obser-
vation of a great number of productions of hybrid Bees, it must
therefore be regarded as certain, that, in accordance with Dzier-
zon's theory, Bees of pure race are deprived of the power of pro-
ducing hybrid drones.

Notwithstanding the experiments hitherto made in a practical
way, by which Dzierzon's theory has acquired the right of assert-
ing its justice, we cannot reject the demand that, by means of direct
experiments, we must acquire the conviction that the drone-eggs
require no fertilization for their development, whilst the same eggs,
in order to furnish female or worker-bees, must be fecundated',
for it is only by such strict scientific proofs that this new theory
will acquire a firm and secure basis.

Since the production of fishes by the artificial fecundation of
the eggs had been carried on of late years with such fortunate
results, it was natural to think whether it was not possible to
establish the correctness of Dzierzon's theory incontrovertibly

re

PARTHENOGENESIS

by the artificial impregnation of the Bee's eggs. But this mode
of proof was necessarily given up again at once as impracti-
cable, for whoever submits the eggs of Bees to a close examina-
tion will immediately see that these eggs, from their extreme
delicacy, are quite unfitted for such experiments. There
would be no possibility of extracting mature eggs uninjured
from the ovaries, in order to transfer them either unfecundated
or artificially impregnated into cells, to be taken care of by the
Bees ; nor would these delicate eggs bear, without injury,
the contact of a brush, however fine, moistened with the semen
of male Bees, as would be required for artificial impregna-
tion. Leuckart proposed* to employ egss which had already
been laid as drone-eggs in drone-cells, and to fertilize them arti-
ficially afterwards, in order in this way to decide the question,
whether we should succeed by artificial impregnation in deve-
loping such eggs into workers or queens. He called atten-
tion, however, at the same time, to the difficulties which are
opposed to the success of this experiment. Leuckart justly
pointed out, that only very fresh and newly deposited drone-eggs
should be made use of for artificial fecundation ; for as soon as
the thin albuminous coating, with which the eggs of insects are
laid, becomes dry, which certainly takes place very quickly on
deposited eggs, the semen employed for artificial impregnation
can no longer penetrate through the pores of the egg-shell into
the interior of the egg, by which means alone, as will be shown
hereafter, the fertilization of the eggs of insects can be com-
pleted. From the importance of the object which would be
attained by these experiments, difficult as they are to carry out,
1 heartily join in Leuckart's wish, that such experiments should
be undertaken by many hands ; perhaps one or other of the ex-
perimenters would be so fortunate, by the concurrence of several
favourable accidents, as to attain what from Dzierzon's theory
must a priori be expected as the result. From the preceding
statements it follows that the artificial impregnation of Bees' eggs
could not as yet be employed in favour of Dzierzon's theory.

Very different hopes were awakened in this respect, when we
became acquainted with the existence and office of the micropyle

See the Bienenzeitung. 1855. p. 206.

IN THE HONEY-BEE.

77

of the eggs of insects. Since Leuckart and Meissner* have
seen the spermatozoids penetrate the egg-shells through peculiar
openings into the interior of the eggs of insects, we must say
beforehand, that, if Dzierzon's theory proves to be correct, this
process can only be observed in those eggs of Bees which are
destined for the evolution of females or workers ; and that in the

* I may be permitted, in reference to the discovery of this extremely import-
ant and interesting phenomenon in the history of the fecundation of the eggs
of animals, to mention the two names of Leuckart andMeissner; for according to
epistolary communications upon this discovery, which I have in my hands from
Meissner, I cannot but believe that both naturalists made their observations and
discoveries on the eggs of insects independently of each other, and perhaps
simultaneously. In a letter of the 8th of July 1854, which lies before me,
Meissner writes from Gottingen : — " I have continued my observations upon
fecundation, and indeed amongst insects. The result is briefly as follows : —
In Diptera, Lepidoptera and Coleoptera, all the eggs have a micropyle at a
definite spot, both in the chorion and vitelline membrane, and the spermatozoa
penetrate from the seminal receptacle into the micropyle during the passage
of the eggs through the vagina. In the Crustacea it is generally the same.
I am still constantly occupied with investigations. In Musca vomitoria I
found the still living spermatozoa in a mass, half in the yelk and half pro-
truding from the micropyle. I am already busy with the elaboration of what
I have found up to this time ; drawings are prepared, and in a few days I
think of sending you the memoir to which I have just referred in a supple-
ment to my last paper, and as a continuation of the latter." (See the Zeit-
schrift fur wissenschaftliche Zoologie, band vi. p. 263.) These observations
of Meissner's were printed in the 2nd heft of the Zeitschrift fur wiss. Zool.
band vi. p. 272 (published on the 14th of September 1854). On the 17th of
August 1854, at the Meeting of the Berlin Academy of Sciences, J. Miiller
read an epistolary communication, of the 12th of August in the same year,
from Professor Leuckart of Giessen, on the micropyle of the eggs of Insects
(Bericht der Akad. der Wiss. zu Berlin, 1854, p. 494). This Report is pub-
lished in separate monthly parts, of which the part for August had not yet
reached me, when, on the 12th of October 1854, after my return from a vaca-
tion-journey of two months to Munich, I wrote my letter to Herr von Ber-
lepsch. Consequently when in this letter (see Bienenzeitung, 1854, p. 230)
I only mentioned Meissner's observations upon the micropyle of the eggs of
Insects, I was still unacquainted with the investigations which Leuckart had
made, as he himself admits, almost simultaneously, in the same department of
entomology. After this explanation, I think Leuckart has no longer any
reason to reproach me with having ignored his investigations (see the Bienen-
zeitung, 1855, p. 129, and Leuckart's memoir Ueber die Mikropyle und den
feinern Bau der Schalenhaut hex den Insekteneiern, in M tiller's Archiv, 1855,
p. 245).

78

PARTHENOGENESIS

eggs which remain unfecundated, from which only drones are
developed, no spermatozoids will penetrate through the micro-
pyle, whilst the micropyiar apparatus must exist in exactly the
same degree of development in all these eggs, as all eggs are
originally of one and the same kind and nature.

Those eggs of Bees which have to undergo a fertilization are
fecundated at the moment when they slip past the orifice of the
seminal duct of the receptacle within the oviduct (vagina). At
this moment, as we may certainly suppose, some spermatozoa
are pressed forth out of the efferent duct of the seminal receptacle,
and these, in this way, by means of their mobility find an oppor-
tunity of penetrating through the micropyiar apparatus into the
interior of the egg. That the act of fecundation of the insect-
egg actually takes place at the point in the vagina just men-
tioned, was asserted by me in the year 183/, and confirmed by
an observation which I made upon Musca vomitoria*. In
Musca vomitoria and its allies, which had not yet completed the
business of oviposition, or perhaps had been disturbed in it, and
had not immediately met with another suitable place for the
deposition of their eggs, the eggs occurring in the ovarian tubes
and in the oviduct differed in the following extremely interesting
manner. The egg, which was fixed between the vulva and the
orifice of the seminal receptacle, had already begun to develope
itself, and contained an embryo; whilst the egg found in the
oviduct above the orifice of the seminal duct, which was per-
fectly equal in size with the preceding one, did not betray a
trace of the commencement of the development of the embryo,
any more than the eggs contained in the Fallopian tubes. In
such female Flies the seminal receptacle always contained mobile
spermatozoa. At that time we contented ourselves, in the ex-
planation of the process of fecundation, with the supposition that
the contact of the spermatozoids sufficed to incite the egg to
development ; more recently we have been compelled to drop
this theory of contact, since we have been able to trace the pene-
tration of the spermatozoids into the interior of the egg. The
process of impregnation will now have to be more precisely con-
ceived in the following manner : — The fecundation and capability

* See Muller's Archiv, 1837, p. 424.

IN THE HONEY-BEE.

79

of development of the egg are not produced merely by the imme-
diate contact of the semen with the egg, but the elementary con-
stituents of the semen, the mobile seminal filaments, must actually
slip into the interior of the egg, very probably to become de-
stroyed here at first, to be dissolved and then mixed with the
elementary constituents of the egg*. For this purpose the eggs
of insects possess a micropylar apparatus, that is to say, one or
more small apertures at one of the poles, through which the
spermatozoids must get into the interior as far as the yelk of the
egg, in order to complete the act of fecundation.

Leuckart was the first to set himself the task of ascertaining
by direct observation, to what modifications the penetration
of the spermatozoids through the micropylar apparatus of the
eggs of the Bee would be subjected according to Dzierzon's
theory. For this purpose he went to Seebach at the end of May
last year, in order to be able to make use of the most abundant
selection of the necessary objects for investigation. A better
opportunity for such investigations could be presented to him
nowhere else than in the immediate vicinity of the grand Bee-
establishment at Seebach, in which however we must also take
into account the disinterested liberality with which Herr von
Berlepsch sacrificed his apiarian riches for the purposes of such
physiological and anatomical investigations.

Leuckart* s intention had already been announced by Berlepsch
in the Bienenzeitungf, and I was therefore extremely anxious to
know what results Leuckart would obtain from these Seebach
studies. These have been recently published by Leuckart in the
above-mentioned Journal, from which J I will here communicate
the most important of the results.

Leuckart was of course obliged in the first place to turn his
particular attention to the micropylar apparatus of the eggs of
Bees, of which he gave the following description § : — " As in the
eggs of most insects, we distinguish in that of the Bees two

* The cases of true Parthenogenesis are, of course, to be understood as
forming the exceptions to this rule,
t For 1855, p. 82. 2.

X Bienenzeitung, 1855, Nos. 17 and 18 (published on the 30th of September),
p. 99. Seebacher Studien.

§ See loc. cit. supra, p. 204. 2.

-0

PARTHENOGENESIS

membranes : an inner one. the so-called vitelline membrane, and
an outer one, the egg-shell or the chorion. Both membranes
are extremely thin and delicate : even the outer one, which other-
wise (especially in those eggs which are deposited freely) is of
considerable thickness and firmness : the vitelline membrane is
structureless, whilst the chorion is covered with a delicate hexa-
gonal lattice- work, as with a network, as far as the hinder (lower)
flattened end of the egg which serves for its attachment. The
micropylar apparatus lies at the anterior or superior pole of the
egg, which is the last excluded during oviposition (and after-
wards contains the head of the young larva). At this point,
where the ridges of the chorionic network run together, we see
a little fan-shaped figure (of about millim.) with about twelve
ravs. The rays of which the face is composed form the optical
expression for the same number of micropylar canals, which run
under the surface of the chorion. At their lower diverging ends
these canals are open externally, whilst they open into the in-
ternal space of the eggs with their opposite extremities. The
structure is exactly the same as in a number of other Hymeno-
ptera (see Mullers Archiv, 1S55, p. 236. taf. 11. figs. 12, 13),
but with this distinction, that in this case the micropylar canals
are most extraordinarily thin and delicate ; so that we can hardly
convince ourselves with certainty of their real nature, and at the
first glance might almost be inclined to regard the ravs as ridges,

CD C « O *

such as also occur on the other parts of the chorion. The canals
can hardly be more than millim. in diameter, certainly still
sufficient to allow the passage of a seminal filament. During
the last period of its stay in the ovary, the Bee's egg receives
another external coating of an albuminous nature, which indeed
is reduced to almost nothing on the anterior (superior) half, but
gradually thickens posteriorly, and acquires a very considerable
development at the flattened posterior (inferior) pole. This
albuminous deposit serves for the attachment of the egg to the
wall of the cell." Although I do not quite agree with this
Leuckartian conception of the micropylar apparatus of the Bee?s
eggs,and I am especiallycompelled to regard the above-mentioned
micropylar canals as something else, a detailed criticism of this
representation of Leuckart's would lead me too far, and 1 there-
fore reserve this for another occasion, and will make use of the

IN THE HONEY-BEE.

81

expression micropylar apparatus, without connecting therewith
exactly the same idea as that which has been formed of it by
Leuckart. The possibility of success in the above-mentioned
(p. 76) artificial impregnation must depend, as Leuckart has
very justly observed *, upon the thin albuminous coat of the eggs
of Bees, for as soon as this albuminous coat has dried, which
will certainly be the case within a few minutes of the deposition
of the eggs in the waxen cells, the orifices of the micropylar ap-
paratus will be plastered over with it, so that the seminal fila-
ments will be prevented from penetrating into the interior of
the egg.

Leuckart's statement alsof, that it is impossible, from the
external condition of the Bee's egg, to arrive at any conclusion
as to the sex of the Bee which is to be developed in it, is im-
portant, and I can fully confirm it.

Leuckart now hoped % " by the assistance of the microscope
to ascertain the presence or absence of the seminal filaments
upon the micropylar apparatus of freshly-deposited drone-eggs,
and from this to draw a conclusion as to their fecundation or
non-fecundation," as he knew " that in many cases it is not
difficult to discover the seminal filaments singly or in strings,
sometimes even in very considerable ones, in the albuminous layer
covering the micropyle in freshly-laid eggs, and even to witness
the act of slipping in through the micropyle." Unfortunately
these hopes were not fulfilled, for Leuckart was compelled to
admit that what he observed is not sufficient for the decision
of the question, and only possesses some value in as far as
Dzierzon's hypothesis is not directly contradicted by it.

Leuckart accounts for the failure of his design as follows { : —
"The Bee is one of those insects which in fecundation only
deposit very few seminal filaments, perhaps in many cases only a
single one, upon their eggs. Important and significant as this
circumstance is for the practical breeding of Bees, as only by it
does it become possible that the queen, notwithstanding her
immense fertility, can lay eggs for years together without ex-
hausting the contents of her seminal receptacle — it is evident
that it is equally unfavourable and unwelcome to the physio-

* See Seebacher Studien, loc. cit. supra, p. 206. 1.
t Loc. cit. p. 204. 1. % Loc. cit. p. 205. 1.

G

82

PARTHENOGENESIS

logist who is in search of these filaments. To this we may
further add, that in Bees' eggs the seminal filaments have not to
penetrate through a thick albuminous layer before reaching the
chorion, as is so frequently the case in other insects, but that
they are deposited almost immediately upon the micro pylar
apparatus, and consequently can penetrate through its canals in
a very short time. Lastly, if we consider the difficulties which
are thrown in the way of the microscopic preparation of the
Bee's egg by the great elasticity and the delicate texture of the
chorion, we can hardly complain of an observer if he has not
arrived at any satisfactory result in this case. I admit freely,
that the investigation of the Bee's egg has been the most diffi-
cult of all the numerous investigations of this kind which I have
undertaken during the last two summers."

By an unlucky chance, Leuckart whilst in Seebach found
no opportunity of examining perfectly fresh-laid Bees' eggs,
and at the time when Leuckart undertook these investigations,
Von Berlepsch could by no means bring a queen to deposit
her eggs. As the result of these Seebach studies, therefore,
Leuckart could only furnish the editor of the Bienenzeitung
with the following information : — " But you wish, then, to
know to what my investigations have led in general ? I reply
that on two occasions only I met with some undoubted seminal
filaments upon the micropyle of Bees' eggs ; on one occasion a
single filament, on the other several, four or five (and yet I have
most carefully examined more than fifty Bees' eggs !). On both
occasions it was upon worker-eggs that I found the seminal
filaments. In drone-eggs I have never been able to distinguish
a seminal filament, although I probably examined more drone-
eggs than worker-eggs, and amongst these such as had been laid
at the utmost a quarter of an hour previously. You see, the
result is doubtful. At all events it appears rather to speak in
favour of, than against, Dzierzon ; but I must again repeat that
this appearance is possibly deceptive. In the interest of science,
it would delight me exceedingly if other observers should be
more fortunate than I have been in this respect."

For the satisfaction of Leuckart I may state here, that I have
actually been more fortunate than him, and that I have seen
what his eyes did not succeed in beholding. " Until " (so

IN THE HONEY-BEE.

83

Leuckart closes his statements* relating to this subject), "either
by experiment or by direct observation, the strict proof is
obtained, that it is only the eggs of the female Bees that are
impregnated, the question as to the causality of sex in the Bees
remains an open one. Theoretical and other reasons may
henceforth induce us either to support or oppose Dzierzon,
and we may increase the materials for the settlement of this
question in an indirect way — its decision cannot possibly be
brought about thereby." I have in fact been able to furnish by
direct observation that evidence which must have been required
by science as alone sufficient for the establishment of Dzierzon's
theory. How far I may consider myself justified in this asser-
tion, may be ascertained from the following statements : —

Although I knew that Leuckart was about to commence the
above-mentioned investigations at Seebach, I had also long before
undertaken to make similar investigations in the interest of
science. Without knowing that Leuckart had already carried out
his Seebach studies, and without being acquainted with the
results which he had obtained from them, I also went to Seebach
in the middle of August last year, because I was convinced
that such investigations could only be undertaken by the aid of
the abundant materials which would there stand at my command
by the acknowledged complaisance of Herr von Berlepsch ; I
certainly entertained but little hope of attaining my end, as
the season of the year was already too far advanced for such
investigations. On the 21st of August I was received by Herr
von Berlepsch with the assurance, calculated to inspire very little
courage, that I would probably find it difficult to meet with the
necessary material, which I required for my investigations, at
so late a period of the summer, and therefore that I had little
chance of solving the problem before me, especially as Leuckart
had been here at Whitsuntide, and therefore at a more favourable
season of the year, but had departed without attaining his object,
and confessed to Von Berlepsch that the questions relating
to Dzierzon's theory could not be solved by the microscope on
account of the very great difficulties which were to be overcome
in the investigations to be made for that purpose. Nevertheless,

* Loc. cit. supra, p. 206. 2.

G 2

S4

PARTHENOGENESIS

I did not allow myself to be deterred from entering upon these
investigations.

I was, however, actually astonished at the Bee-material which
offered itself to me in Seebach, for the masses of Bee-colonies,
as well as their judicious arrangement, so favourable to observa-
tions of every kind, surpassed all my expectations. I found
104 Dzierzon hives overflowing with honey and bees, destined
for hybernation, and indeed distributed in various ways in eight
places in a spacious orchard, amongst which I was particularly
surprised at the pavilion containing 28 bee-hives, already
frequently referred to in the Bienenzeitung. The distance of
these eight Bee-establishments from each other was never more
than 40 feet Rhenish. Amongst these hives there were nine
genuine Italian colonies of Bees, the number of which might
have been much greater, if, as Herr von Berlepsch asserted,
seventy Italian mothers had not been furnished by him to other
Bee-keepers, and the hives generally very much prejudiced by
the various scientific experiments*. What has been of particu-
lar service to Von Berlepsch in his Bee-keeping is the assistance
of his servant Giinther, who, being endowed with excellent
talents, has been instructed by Berlepsch himself in the mystery
of Bee-keeping, and has approved himself in a distinguished
manner t.

I immediately set to work and examined a great number of
female eggs, with which the great Bee-establishment of Herr
von Berlepsch still furnished me in large quantities. It first
occurred to me to make myself well acquainted with the organi-

t What advantages may be obtained with the assistance of Dzierzon's hives,
bv assiduity and attention, and especially by the proper comprehension of the
mode of life of Bees, will be seen by the dexterity with which Herr von
Berlepsch manages his bee-hives even in a district which is poor in honey, as
Seebach is described by himself (see Bienenzeitung. 1855, p. 3). According to
Berlepsch' s assertion, every one of his hives would be capable of giving him
annually 30 pounds of honey and 1 1 pound of wax, according to which 3120
pounds of honey and 130 pounds of wax, of the value of fully 400 dollars,
might accrue to him from the whole 104 hives.

* This excellent assistant, who, as his master asserts, and I can testifv,
may be placed beside Huber's servant, Francois Burnens see F. Huber, Xou-
celles Obserc), has unfortunately been compelled to leave Seebach for the
present, to pass his years of military service.

IN THE HONEY-BEE.

85

zation of the eggs of Bees, so as to be exposed to no delusions
or errors subsequently in seeking for the spermatozoids. It was
only after I had exactly ascertained the structure of the egg-
envelopes, the micropylar apparatus and the yelk, and practised
myself in the preparation of the eggs of Bees, that I turned my
attention to the spermatozoids, by whose presence or absence
the principal decision was to be given. Above all, the most
exact acquaintance was required with the individual ridges of
the lattice-work of the egg-shell, which is composed of irregular
hexagons, as well as with the folds of the vitelline membrane
accidentally produced during examination, so as not to confound
these things with spermatozoids which had become motionless.

After I had, in this way, made myself sufficiently familiar with
the examination of the eggs of Bees, I had a comb brought to
me at 10 o'clock in the morning of the 22nd of August, contain-
ing female eggs, which had been deposited at the utmost an hour
before. I might expect beforehand that no trace of spermato-
zoids would be recognizable externally in these eggs ; I there-
fore directed all my attention to their contents, and hoped to
discover the spermatozoids which had already penetrated through
the micropyle, in the interior of the eggs. I soon convinced
myself that there was no possibility of discovering the delicate
seminal filaments between the granulo-vesicular yelk-masses ; the
linear object to be sought for was too subtile to be capable of
discovery with certainty amongst the many mutually-crossing
outlines of the yelk-vesicles. After various vain endeavours to
render the interior of the Bee's egg accessible to the inquiring
eye, I came at last to the idea of employing an artifice, which I
had soon acquired by practice, and which allowed me to survey
at least a portion of the inner space of the Bee's eggs with great
clearness and tranquillity. I crushed a Bee's egg quite gently
with a very thin glass -plate, and so that it was ruptured at its
lower pole, opposite to the micropylar apparatus, and the yelk
gradually flowed out at this spot, by which a clear empty space
was produced at the upper pole within the micropylar apparatus,
between the egg-envelopes and the yelk which was retiring
downwards. I directed my attention very particularly to this
empty space, which I saw slowly produced under the microscope
during the effusion of the yelk. The production of such a pre-

86

PARTHENOGENESIS

paration of course was not always successful, for sometimes the
yelk flowed out of the ruptured envelopes, without the produc-
tion of this empty space ; the yelk also remained diffused in the
upper part, and allowed of no certain judgment as to the pre-
sence or absence of seminal filaments. An error in crushing the
egg, a little too much pressure upon it, or perhaps also a pecu-
liar, less tenacious consistency of the yelk, probably caused the
contents of the yelk to retire in every direction from the pressure,
and therefore also to press upwards against the micropylar
apparatus.

From the above-mentioned comb I examined ten eggs, which
I succeeded in transferring uninjured from their cells upon an
object-glass, which, from the delicacy of these eggs, is always a
matter of difficulty. The result of their microscopic examina-
tion was as follows : —

The first female egg exhibited nothing remarkable. In the
interior of the second egg, to my great delight, I observed three
distinct, but motionless seminal filaments within the empty
space which had been produced at the superior pole of the egg
by the flowing out of the yelk through the inferior pole. In a
third egg, after the same retirement of the yelk, I saw, in the
superior space of the egg which had become empty, a single
motionless seminal filament. In a fourth egg, I again observed
three motionless seminal filaments at the same spot. A fifth
egg, prepared in the same way, exhibited no seminal filaments.
A sixth and a seventh had probably been too strongly squeezed
in their preparation ; the necessary empty space could not be
produced in the interior of the egg at its superior pole, for which
reason I regarded these preparations as of no use for investiga-
tion. In an eighth and ninth egg, fortunately prepared, I again
saw a single motionless seminal filament in the superior empty
space of the cavity of the egg. In the tenth egg the preparation
was quite unsuccessful. This same comb with female eggs, after
being carefully preserved in a room, was made use of for the
continuation of these investigations at 8 o'clock in the morning
of the 23rd of August. An eleventh egg was spoilt during the
preparation ; as was also a twelfth. A thirteenth egg was in an
extremely interesting condition. After it had been for twenty-
two hours out of the bee-hive and had been successfully pre-

IN THE HONEY-BEE.

87

pared in the way above described, it exhibited two spermatozoids
in the clear empty space between the egg-membranes and the
yelk which had retired on the crushing of the egg. One of the
seminal filaments performed very lively tortuous movements ; the
second filament was rigid, but adhered firmly to the other
seminal filament, and was thus moved by its movements. These
movements were first seen by me at about half-past eight, and
were also observed by Von Berlepsch and Giinther and by two
other witnesses. Three minutes afterwards the seminal filament
was still active. The preparation was then put by, and not again
examined under the microscope for fifteen minutes. The move-
ments of the first seminal filament had then ceased also, but
both spermatozoids, although motionless, were still clearly di-
stinguishable in the same spot. A fourteenth egg furnished no
result, its preparation being unsuccessful. In a fifteenth, four
distinct but motionless spermatozoids were discoverable in the
space which had become empty during the preparation, between
the envelopes and the retreating yelk.

On the same day, another comb with female eggs was removed
from another bee-hive ; it might at the utmost have been twelve
hours old. The investigations continued with these eggs gave
the following results. A sixteenth egg, the preparation of which
turned out well, exhibited no seminal filaments in its interior.
With the seventeenth egg the preparation was unsuccessful.
An eighteenth egg contained three seminal filaments in the spot
above mentioned; one of these was active. In the nineteenth
and twentieth eggs the preparation was unsuccessful. The
twenty-first contained two motionless seminal filaments, as did
also the twenty-second. In the twenty-third egg, on the con-
trary, I could distinguish four motionless seminal filaments.
With the twenty-fourth and twenty-fifth eggs the preparation
was unsuccessful. The twenty-sixth and twenty- seventh again
exhibited a single motionless filament, and the twenty-eighth
two of them. The four following eggs all showed only a single
motionless seminal filament. The examination of the thirty-
third egg was again unsuccessful. The thirty-fourth and thirty-
fifth eggs exhibited three motionless spermatozoids, and the
thirty-sixth egg examined by me contained one active and three
motionless seminal filaments. In the thirty-seventh and thirty-

88

PARTHENOGENESIS

eighth eggs I could only perceive a motionless spermatozoid ; in
the thirty-ninth, fortieth and forty-first, on the contrary, I was
able to discover two rigid spermatozoids.

On the 23rd of August a third comb furnished with female
eggs was also employed for investigation, the eggs in which
had only just been deposited. These eggs, however, did not
show themselves so favourable to the above-described mode
of investigation employed by me, because the yelk would
not detach itself so easily from the vitelline membrane after
the rupture of the envelopes; where I succeeded in pro-
ducing the empty space between the envelopes of the egg
and the yelk in these eggs, I often found it possible to dis-
cover spermatozoids in their interior. Not to weary the reader,
I will only enumerate a portion of these investigations in their
order : — The forty-third egg allowed a motionless seminal fila-
ment to be detected, sitting externally upon the micropylar
apparatus. The forty-fourth and forty- fifth eggs furnished no
results, from unsuccessful preparation. The examination of these
was not repeated until seven o'clock in the morning of the
24th of August, when these deposited eggs were fifteen hours
old. The forty-sixth egg contained several coiled but motionless
spermatozoids. In the forty-seventh egg I was able to discover
one motionless seminal filament ; with the forty-eighth the pre-
paration was unsuccessful, and with the forty- ninth and fiftieth
I was obliged to leave it doubtful whether the object which
might have been taken for a seminal filament, was such in
reality. Both the fifty-first and fifty-second eggs allowed a
motionless seminal filament to be clearly distinguished in the
empty space, when the yelk had retracted itself downwards from
the micropylar apparatus by the rupture of the egg-shells.

If I sum up the observations just referred to, they furnish
on the whole a very favourable result, considering the difficulties
of the investigation, for I have also convinced myself, that these
investigations of the egg of the Bee, are, as Leuckart has very
justly asserted*, amongst the most difficult of all investigations
of the kind. Amongst the fifty-two female Bee-eggs examined
by me with the greatest care and conscientiousness, thirty fur-
nished a positive result; that is to say, in thirty, I could prove
* See his Seebacher Studien m the Bienenzeitiuty, 1855, p. 205. 2.

IN THE HONEY-BEE.

89

the existence of seminal filaments, in which movements could
even be detected in three eggs. Of the other twenty -two eggs,
twelve were unsuccessful in their preparation. At the same time
I may also indicate particularly, that the observations with posi-
tive and negative results followed each other quite irregularly,
but alternating at very short intervals, which probably was only
dependent upon the favourable or unfavourable consequences of
my preparation of the eggs employed for observation. If the
question is to be raised, why Leuckart was not so fortunate as
to see what I have succeeded in seeing, I can make no other
answer, but that probably the different method followed by us
in our investigations, is to be blamed for Leuckart^s want of
success. Berlepsch informed me, that Leuckart did not exa-
mine the contents of the eggs by the careful compression of the
Bee's egg, but that he confined himself to submitting the eggs
in a perfectly uninjured state to an external examination.

It is certainly to my mode of investigation alone that I am
indebted for the successful result of these observations, which
were made with an excellent microscope of Kellner's. The
careful rupture of the egg-membrane effected always by me,
must prove an extremely important manipulation, for by this
alone was it possible evidently to isolate the delicate seminal
filaments which had penetrated into the cavity of the egg and
become concealed by the yelk-mass, as, after penetrating into
the egg they probably continue adhering for some time to the
micropylar apparatus by their caudal extremity and remain
behind, isolated in the upper empty portion of the cavity of the
egg during the issue of the yelk-mass after the rupture of the
membranes.

Above all things, however, it was of consequence to me that
I should be able to examine male eggs (drone-eggs) also in
exactly the same way, and Herr von Berlepsch actually pro-
cured me the means of doing this, although at first he had given
me but little hope of obtaining such drone-eggs even in small
number. It was truly a chef-d'oeuvre to obtain drone-eggs at so
late a season : how my acute and experienced friend as it were
compelled a queen to lay male eggs, the reader will be able to
understand from what follows.

In No. 79 of his Bee-hives, Herr von Berlepsch possessed a

90

PARTHENOGENESIS

queen, which he knew to be near her death, as her Bees had
been constantly constructing royal-cells since the end of June,
and the queen furnished these with eggs by which her loss
might be replaced. Berlepsch, however, had not permitted the
larvae in these cells to come to exclusion, and thus this aged
mother was still alive when I arrived at Seebach and inquired for
drone-eggs. A little while before, this queen had laid drone-
eggs, but Berlepsch had destroyed this drone-brood also, as being
useless. At last the workers had enough of it, and commenced
no more cells. Berlepscrr's object in this case was to determine
how long the life of a queen might be prolonged artificially.
When I came to Seebach, this queen was still laying single
eggs. On the 21st of August Gunther received the charge to
feed the hive, No. 79, in the evening with fluid honey ; the next
evening (22nd of August) two combs with covered worker-brood,
and between the two an empty drone-comb, were suspended in
this hive. The following morning (23rd of August) there were
twenty-seven drone-eggs in this drone-comb, and about sixty
worker-eggs in open cells of the worker-combs. Berlepsch had
carefully ascertained previously that not a single egg was present
in the open cells of both the foreign worker-combs, when sus-
pended in the experimental hive.

I examined these twenty-seven drone-eggs, which might have
been about twelve hours old, and which agreed perfectly both in
their appearance and organization with the female eggs, with the
same care and by the same method with which I had treated
the female eggs, and did not find one seminal filament in any
single egg, either externally or internally. I must also add, that
only the seventh, thirteenth and twenty-third eggs were unsuc-
cessfully prepared. In all the rest of these drone-eggs the yelk
retreated slowly and completely from the upper pole of the
egg-envelopes, after the bursting of the membranes ; the desired
empty clear space between the micropylar apparatus and the
retreating yelk was produced in the interior of these eggs, so
that if seminal filaments had been present in them, they cer-
tainly would not have escaped my searching and inquisitive eye.
In order to be quite satisfied as to this remarkable negative
result, and to obtain the full signification of it, several female
eggs of the same queen which had furnished these drone-eggs,

IN THE HONEY-BEE.

91

were examined for comparison ; for the objection might certainly
have been raised, that this queen might have laid nothing but
barren eggs, as, being already weakened by age and near her
death, she might have had no more spermatozoids in her seminal
receptacle. Nevertheless, many of these eggs contained seminal
filaments ; they were the twenty-seven eggs already mentioned
by me, — namely the sixteenth to the forty-second eggs.

To this result of my Seebach investigations, which proves the
correctness of Dzierzon's theory by direct observations, I may
also add that Herr von Berlepsch has lately informed me by
letter, that this queen subsequently, after my departure from
Seebach, also laid female eggs, from which workers were deve-
loped, but she herself only died on the 19th September, 1855.

92

TRUE PARTHENOGENESIS IN THE SILK-WORM MOTH.

Having proved the occurrence of a true Parthenogenesis, com-
bined with such extremely remarkable phaenomena, in the Bees,
I return once more to the Lepidoptera, in order to refer to the
Bombyx Mori, regarding which notices were constantly coming
to my ears, sometimes here, sometimes there, which indicated
the Silk-worm Moth as one which sometimes laid eggs capable
of development sine coucubitu. The older statements relating
to this appeared to me at first to be equally unfounded with
the other cases of Parthenogenesis in the moths elucidated by
me (p. 12).

How little inclination there was even formerly to believe in
any such Parthenogenesis of the Silk- worm, appears from a letter
written by Constans de Castellet, General Inspector of the Silk
establishments in the kingdom of Sardinia, in which* he reports
that eleven female silk-worm moths which had just crept out of
the cocoon were observed by him, which, in their virgin state,
deposited eggs, from which caterpillars and cocoons were
reared. Castellet, who had not expected this, and wished to be
sure that he had not deceived himself, repeated the experiment,
imprisoned the female cocoons in different rooms, and convinced
himself of the thriving of the silk-worms which he afterwards
obtained from the virgin brood deposited by these moths. He
made a report upon this case to Reaumur, who however an-
swered him shortly : ex nihilo nihil fit, and doubted the cor-
rectness of the facts. By such an answer from so distinguished
a naturalist, Castellet found himself induced to investigate the
affair closely once more, and believed that he had at last got at
the reason of it, by thinking that he saw that silk- worms in his
breeding-place, which were already very near the time for spin-
ning themselves up, had copulated. He thought he observed,

* See the letter referred to : Sulle uova de' vermi da seta fecondate senza
V accoppiamento delle farfalle, in the Opuscoli Scelti sidle scienze et sulle arti,
torn, xviii. 1/95, p. 242.

PARTHENOGENESIS IN THE SILK-WORM.

93

namely, that some caterpillars had united quickly and others
more slowly for a moment with the hinder extremity of their
body. What is to be thought of this observed union, may be
left to every one who is acquainted with the anatomical con-
struction of an adult caterpillar, as regards the generative
organs.

A later notice relating to this subject is the assertion of
Herold, according to which*, amongst the eggs of an unferti-
lized silk-worm moth, some here and there are said to have
passed wholly or partially through the same changes which are
observed in eggs fertilized by true copulation, whilst most of
the eggs remained unaltered. Herold, in his representation of
the development of the egg of the silk-worm moth, even di-
stinguishes between foetuses developed from fecundated and un-
fecundated eggs, of which the former make their escape, wrhilst
the latter always remain in the egg-shell and dief. Although
Herold has not stated more precisely what precautions he took
to attain the certain conviction that the brood produced from
unfertilized eggs was actually derived from virgin females, I
nevertheless looked upon the above assertion of Herold with
less distrust than upon the before-mentioned examples of sup-
posed Parthenogenesis derived from the history of reproduction
of the moths, as with the very sluggish silk- worm moths, which
do not fly about in the open air, there could be much less
probability of the occurrence of a secret and unobserved copu-
lation.

It is remarkable that this spontaneous evolution of the embryo
in unfecundated eggs, mentioned by Herold, an observation w hich
might easily be repeated upon the Silk-worms, which are so
widely diffused, has hitherto escaped the attention of physio-
logists. Herold was the first who furnished an exact and de-
tailed description of those changes which may be detected with
the lens in a determinate sequence in different silk-wTorm eggs
developing themselves without fecundation. He described first
of all, upon the sixth plate of his Disquisitiones^, the consecutive

* Disquisitiones de animalium vertebris carentium in ovo formations
Fasc. ii. 1838, tab. 7.

t Loc. cit. tab. 7- fig. 31.

X Disquisitiones, &c. Fasc. ii. 1838.

94

PARTHENOGENESIS

changes which the silk-worm eggs rendered capable of deve-
lopment by a fertile copulation undergo with regard to their
outline, colour and contents, from the moment of deposition up
to that condition in which they remain more or less unaltered
through the whole winter. He also points out particularly that
the coloured membrane which makes its appearance below the
egg-shell, and which passes through a definite change of colour,
upon which the changes of colour of the whole egg depend,
is certainly in general a sure indication that fecundation has
taken place, but especially the most certain token that the eggs
are actually capable of development. Herold at the same time
figures an embryo* as it occurs in the middle of winter in the
fecundated egg of a silk-worm moth, after the egg has completed
its change of colour within the first eight or ten days after depo-
sition. On the seventh plate Herold represents the consecutive
changes " in regard to outline, colour and contents undergone,
in the first weeks after deposition, up to the state in which
they remain more or less unaltered throughout the winter, by
many of the eggs which the female silk-worm moth lays by her-
self, without copulation with the male, and many of which are
nevertheless endowed in different degrees with the power of de-
velopment almost like those which are actually rendered fertile
by the assistance of the male." He could distinguish various
degrees of the faculty of development of unfertilized eggs, which
manifested themselves by infinite differences in the disposition,
number, form, and strength of colour, of the coloured parts of
the egg. In some of these unfecundated eggs the faculty of
development had attained such a high degree, that Herold was
able to extract a foetus from one of them in the middle of winterf.
According to Herold's further statements, however, embryos
were not found in all unfertilized eggs capable of development
which he examined in the winter, and he had also never seen
young caterpillars creep out of unfertilized eggs, as they had
previously ceased to live.

Moreover, Malpighi was already acquainted with the distinc-
tion between fertilized and unfertilized silk-worm eggs. This
distinguished naturalist long since knew, what has been left un-

* hoc. cit. sup. tab. 6. fig. 15.

t hoc. cit. tab. 7. fig. 19.

IN THE SILK-WORM MOTH.

95

noticed by a later physiological school, namely that the ovaries
were not fertilized by copulation, but that after a copulation each
individual ready-formed egg is fertilized for itself. This appears
distinctly from his published investigations. Malpighi saw*
that the sulphur-yellow eggs taken out of the ovaries of a fecun-
dated silk-worm moth behaved exactly like unfecundated eggs ;
whilst an egg, which he discovered in the vagina of this moth,
acquired a violet colour in course of time, and consequently
showed itself to be fecundated. Malpighi derived this influence
from the contents of the bursa copulatrix, the signification of
which and its opening into the vagina he knewf. The seminal
receptacle also certainly had not escaped his searching glance,
but he had not comprehended its importance J. Pallas § also
referred to the changes of colour undergone by the fertilized eggs
of the silk- worm moth and other moths after they have been laid.
He observed that the eggs of a Papilio Iris, which he cut out of
the body of a fecundated female, did not change their grass-green
colour, whilst the deposited eggs of a fertilized butterfly of this
kind became yellowish-green ; and from this he drew the correct
conclusion, that the fertilization of these eggs only takes place
during their passage through the vagina of the mother (see Note
on Hunter's experiments at p. 52).

Exactly at the time when I had become acquainted with the
Parthenogenesis of the Psychidce, my attention was called from
several sides to the occurrence of Parthenogenesis in Bomhyx
Mori, in such a way that I could not avoid a closer examination
of the phaenomena here referred to.

The principal incitement to this was furnished by the following
statement, made in the year 1851 by P. de' Filippi|| : — " Je me
bornerai h, citer un cas singulier, qui m5a ete raconte tout
dernierement par un celebre entomologiste anglais, M. John
Curtis, a son passage par Turin, d'une chrysalide isolee de
Bombyx polyphemus qu'il avait recue de l'Amerique, et de laquelle

* Marc. Malpighii Dissertatio de Bombyce, Londini, 1669, p. 82.
f Op. cit. p. 81. tab. 12. fig. 1. K, I, M.
% Op. cit. p. 80. tab. 12. fig. 1. E, F, G, H.

§ See his Anmerkungen uber einige Besonderheiten an Insekten, in the
Stralsunder Magazin, band i. st. 3. 1768, p. 240.

\\ See Annates des Sciejices Naturelies, Zoologie, torn. v. 1851, p. 297.

96

PARTHENOGENESIS

naquit une femelle dont tous les oeufs se developperent. Je crois
que la raeme chose a lieu quelquefois daus les femelles de Bom-
byx Mori, quoique tout a fait separees des males."

This notice brought to my mind several other communications
as to the possibility of a Parthenogenesis in Bombyx Mori, upon
which I was now compelled to lay the greater stress, after Filippi,
whom I knew to be a thoroughly cautious physiologist, had come
forward as a witness to the correctness of this assertion. I re-
called to mind a statement of Mbgling?s*, that the female moth
of Bombyx Mori lays 350 to 4S0 eggs, which might be capable
of development although the female was not fertilized by any
malet. Here also evidently belongs that observation of Bour-
sier's which was reported some years ago in the Comptes Rendus%,
that a female silk-worm moth, which had not copulated with a
male, had been exposed by Boursier, sometimes to the sun and
sometimes to the shade, during which treatment the moth laid
many eggs, of which those which were laid in the sun furnished
caterpillars. Although no one will attribute the fertilization of
the eggs in the preceding case, as Boursier has done, to the in-
fluence of the light and heat of the sun, we shall not be able to
help seeing a Parthenogenesis in this phenomenon. I applied
to Filippi himself, in order to obtain something further from
him as to the propagation of the silk-worm moth sine concubitu,
as he lives in a country in which the cultivation of silk is carried
on to a very great extent ; and he certainly could easily have
collected observations upon the subject in question. Filippi
wrote to me on the 29th of May 1S52, as follows : — " Quant aux
oeufs de Bombyx Mori eclos sans fecondation prealable, voila ce
que je pourrais ajouter. C'est en 1S50 que j'ai eu occasion
d'observer une chose pareille avec des vers a soie de la variete
dite parmi nous des trevoltini (c'est a dire qui peuvent etre
eleves trois fois dans l'annee). Aussi M. Gnseri, qui s'occupe
beaucoup de ['education des vers a soie, a trouve que plusieurs

* See his book upon the Silk-worm, 184", p. 89.

t Mogling here refers to the Notices sur les Educations des Vers a Soie
faites en 1840 par M. Robinet, which have not yet come under mv notice.

X See Comptes Rendus, No. 12. 1847, or Notizen von Schleiden und Froriep,
band v. 1848, p 20.

IN THE SILK-WORM MOTH.

97

ceufs deposes par des femelles vierges se developpent. Plusieurs
cultivateurs de vers a soie m'ont assures la raeme chose."

These various notices upon Bombyx Mori, taken together with
the observation made by Curtis upon an isolated American
Bombyx, in which no mistake could certainly have slipped in,
as well as an observation reported by Johnston *, according to
which caterpillars were evolved from the eggs taken out of the
body, and therefore unfecundated, of a Smerinthus ocellatus
killed two days previously, — all these statements confirmed me in
supposing the existence of a Parthenogenesis also in Bombyx
Mori, although I have denied this amongst the Lepidoptera, with
the exception of particular Psychidce. I am not on this account
to be accused of an inconsistency, for the examples previously
(p. 12) cited by me, which were supposed to speak in favour of
the Parthenogenesis of the moths, can never be admitted as
credible evidence, for the reasons already asserted.

In order to obtain personal observations upon the Partheno-
genesis in Bombyx Mori, I put myself in communication with
various silk-worm breeders in Breslau and Munich ; from these
also I received the serious assurance, that caterpillars were not un-
frequently developed from the eggs laid by unfertilized female silk-
worm moths. By the courtesy of the manufacturer, Herr Steiner
of Breslau, an extensive silk-breeding establishment was put at
my disposal, with the aid of which I was enabled to inform my-
self upon various interesting processes in the oviposition and
development of the Silk-worm. First of all, in the summer of
1852, I procured a sufficient number of silk cocoons of male and
female sex. After their exclusion, I allowed several pairs to
copulate, whilst I strictly separated and watched another quan-
tity of female moths, which I had already recognized as such in
the cocoons. Both the fertilized females and those which had
remained unfertilized, of which I had selected seven for observa-
tion, deposited a great quantity of eggs, all of which I submitted
to a very careful inspection. Almost all the eggs laid by the

* See the Zoologist, 1848, p. 2269, and also Schleiden und Froriep's No-
tizen, 1849, baud viii. p. 1/0. I presuppose that in the present case the eggs
were taken out of the ovaries, and not out of the oviduct, because otherwise,
after any preliminary copulation, such eggs might have been fecundated from
the seminal receptacle.

H

9S

PARTHENOGENESIS

fecundated silk-worm moths changed in a few days in the well-
known manner, their sulphur-yellow colour gradually becoming
converted into dark yellow, then into orange, red, violet, and lastly
into bluish or slaty-grey, which had often taken place even on the
third day after laying. The eggs at the same time remained
tense, and bore in their middle the flat impression which is also
well known. In this bluish colour, as the token of their vitality,
I got these eggs through the winter, and in the following spring
they furnished me with a great number of caterpillars. I must
here observe, that the previously mentioned change of colour of the
Silk-worm's egg does not arise from a commencement of the deve-
lopment of the embryo, but is only the consequence of a peculiar
alteration of the yelk, which at first shines through the colour-
less, dimly transparent egg-shell with a sulphur-yellow colour,
and subsequently with the various changes of colour. A few of
the eggs laid by the fecundated moths retained their sulphur-
yellow colour, and at last shrivelled up. These certainly lost
their vitality, because from some cause the penetration of seminal
filaments into the micropyle was prevented, and thus the fecun-
dation of these eggs was not attained*.

To the eggs obtained from the seven virgin silk-worm moths I
directed particular attention from the first, as I was very curious
to see whether a Parthenogenesis would not be observable at
least in some individuals of these eggs. I was therefore much
surprised when I perceived exactly the same well-known change
of colour which took place in the fertilized eggs soon after their
deposition, in a far greater number of these eggs than I could
have hoped, but in the unfecundated eggs it occurred much
later and more slowly. From some of these virgin silk- worm
moths I had obtained thirty to forty, from others only about ten
to twenty eggs, the colour of which slowly altered in comparison
with the other eggs which had remained yellow, and which gra-
dually shrivelled up. But this change of colour did not go on
quite constantly in the same way as in the fertilized eggs. Only
a few unfertilized eggs passed through the entire alteration of
colour to the slate-grey ; most of them remained stationary at
earlier steps of the change, only became reddish or violet, and
even shrivelled up at last like the pale yellow unfertilized eggs,

[* This is an insufficient cause, from Siebold's own showing. — W. S. D.]

IN THE SILK-WORM MOTH.

99

but still a month or two later than these. Unfortunately I had
not the satisfaction of obtaining caterpillars from the unfertilized
eggs which had become slate-grey and remained tense, and
which I had preserved with care through the winter, for they
also shrivelled and dried up entirely, when the next spring had
arrived. The same thing happened to me with a great number
of slate-grey and tense eggs, possessing exactly the appearance
of fecundated eggs, which were handed over to me by Herr
Steiner with the assurance that they were laid by virgin silk-
worm moths. After several months I found these eggs entirely
shrivelled, without my obtaining a single larva from them.

In the year 1854, Herr Schmid of Eichstadt, who has occu-
pied himself for eighteen years with the breeding of silk-worms,
sent me a quantity of bluish- grey, tense silk -worm eggs, which,
according to his assurance, were derived from virgin moths.
From all these eggs caterpillars were actually developed. It
was of much consequence to me to rear the moths from these
caterpillars, in order to see whether only a single sex, either only
males or only females, would make their appearance from all
these unfertilized eggs which had arrived at development, as in
the case of the Psy chides and that of the Bees.

Although I could state no definite motive by which I might
have been induced to expect beforehand the evolution of male
moths from the unfertilized eggs of the Silk-worm moth, I must
admit that, although without any definite ground, I cherished
the expectation that those silk-worms evolved from unfertilized
eggs would furnish nothing but male moths. For my justifica-
tion, I might certainly cite that remarkable notice of Carlier's
already mentioned (p. 20), which Lacordaire has communicated
in the following words* : — " Cet observateur a obtenu, sans ac-
couplement, trois generations du Liparis dispar, dont la derniere
ne donna que des males, ce qui mit naturellement fin a Inexpe-
rience." Although, as already remarked, this short notice con-
tains no proof that the observation therein communicated was
made with the necessary care and exactitude, it now acquires a
peculiar importance, since Dzierzon's theory has proved to be
correct. Even in the year 1852, I urged upon Dzierzon himself

* See Lacordaire, Introduction, Sec. torn. ii. p. 383.

H 2

100

PARTHENOGENESIS

the idea, whether the property possessed by certain female silk-
worm moths, of laying eggs capable of development without
fecundation, might not be of use in furnishing aid to his theory
of the reproduction of the Bees, by means of exact trials and
experiments. In consequence of this, Dzierzon recommended
such experiments to the silk- worm breeders*.

Experiments were hereupon made in this direction in several
quarters with silk-worms, but up to this time the reports furnished
of them are still imperfectf- A notice contained in these
Reports from Dr. Kipp, who had obtained a quantity of eggs,
and from all these caterpillars, from a Poplar Hawk-moth [Sphinx
Populi) which had been excluded and kept shut up in a box,
speaks against Dzierzon^s theory, as both male and female moths
were reared from these caterpillars J. I myself took the greatest
trouble with the rearing of those young caterpillars which I had
obtained from the unfecundated silk-worm eggs given to me by
Herr Schmid, and of fifteen caterpillars which grew large, I
brought twelve individuals to spin up. The different forms of
the cocoons at once allowed me to judge that different sexes
would be excluded from them, and subsequently seven male and
five female moths actually crept out of these twelve cocoons. To
convince myself whether these moths produced by Partheno-
genesis were really sexually mature and capable of propagation,
I did not prevent them from copulating, which they did imme-
diately on making their escape. After the performance of copu-
lation the females deposited a number of eggs, which showed
themselves to possess vitality, and in the following year furnished
the same number of caterpillars. Schmid, who had supplied me
from his store of unfecundated, vitalizable silk-worm eggs, made
similar experiments at the same time with the rest of the eggs
which he had retained, and obtained the same result as myself.
That Schmid performed his experiments with great care and with
the necessary caution, appears from the report which he sent
me on the subject, from which I extract the following as wrorthy
of notice. In the year 1853, Schmid captured twenty-four silk-

* See the Bienenzeitung , 1853, p. 103.

t Bienenzeitung, 1853, pp. 144 & 175, and 1855, p. 26.

% Bienenzeitung, 1853, p. 175. 2.

IN THE SILK-WORM MOTH.

101

worm moths immediately on their creeping out of the cocoon, in
order to keep them securely in the virgin state ; they were isolated,
and found themselves compelled, about the 2nd to the 4th day,
to deposit their eggs unfecundated. Some hundreds of these
eggs, which were at first of a sulphur-yellow colour, gradually
acquired the well-known slate-grey tint, and both in this color-
ation and in the rest of their appearance exactly resembled the
eggs of fertilized silk-worm moths. As they thus showed them-
selves to be capable of life, they were carefully preserved by
Schmid through the winter, and in the spring of 1854, when
the mulberry hedges began to get green, they were brought out
of their winter dwelling-place, in order to dispose them for com-
plete development in a suitably warmed place. The exclusion
of the caterpillars took place immediately from 274 unfertilized
eggs laid by 24 virgin silk-worm moths ; in 2?0 other unfertilized
eggs of the same moths the caterpillars were dead before exclu-
sion. As regards the number of vitalizable eggs, which Schmid
obtained from 24 unfecundated silk-worm moths, he remarks that
none of these unfecundated moths laid entirely vitalizable eggs,
but that sometimes vitalizable, sometimes unvitalizable eggs were
deposited in irregular alternation one after the other by one and
the same individual, as immediately after four or ten or fifteen
vitalizable eggs, the same number or more or less of unvitalizable
eggs might be counted ; sometimes entire masses of eggs were
laid, amongst which only one, two, three or four vitalizable
eggs were to be observed. Schmid, like myself, had also made
the observation that all the eggs laid by fertilized female silk-
worm moths are not, without exception, vitalizable, but that in
rare cases single unvitalizable eggs (unfecundated) occur amongst
the other vitalizable (fecundated) eggs. Several of the above-
mentioned virgin female silk-worm moths, however, laid nothing
but unvitalizable eggs. Of the 274 silk-worms obtained from
unfecundated eggs, Schmid could only keep fifteen alive, in con-
sequence of the extremely unfavourable conditions of tempera-
ture which occurred in the spring of 1854 ; he fared no better in
the same spring with the silk-worms obtained from fertilized eggs.
Of these fifteen silk- worms twelve were brought to spin up, and
these furnished eleven moths, amongst which there were seven
males and four females. Schmid allowed three of these female

102

PARTHENOGENESIS

moths tolay eggs withoutfertilization, but all the eggs deposited by
these three virgin female silk-worm moths remained light yellow,
and soon shrivelled, so that they had not been vitalizable. The
fourth of these females paired with one of the seven males which
had been reared from unfertilized eggs ; the eggs laid by this
female after the act of copulation were all, with the exception of
sixteen, vitalizable, and furnished very fine silk- worms in the year
1S55. Of the six other male silk-worm moths, two were employed
to copulate with other ordinary females ; these latter also laid
throughout vitalizable eggs, from which very fine silk- worms were
produced. In the year 1854 Schmid again selected twenty-four
female cocoons of silk-worms, which were all separated singly
and strictly inspected. From these, twenty-three females and
one male escaped; the latter was removed immediately after his
exclusion. The twenty- three females deposited their eggs more
or less irregularly in their solitary cells, and amongst these there
were only twenty-one vitalizable eggs, the whole of which were
laid by four of these moths ; all the rest of the eggs had for the
most part remained pale yellow, or had become reddish-brown,
and then shrivelled. Unfortunately, in the following year, 1855,
the breeding of the caterpillars from these twenty-one eggs was
unsuccessful ; the twenty-one caterpillars had been perfectly de-
veloped in them, but their exclusion must have been retarded
on account of want of nourishment, by which they died within
the egg-shell. In the year 1855, Schmid selected eight female
cocoons, which were separated and watched with equal care and
anxiety. They furnished eight female moths, of which seven
individuals deposited their whole store of eggs in the virgin
state, whilst the eighth female, notwithstanding the greatest
exertion, could not deposit even a single egg. Schmid sent me
the entire harvest of eggs from these moths upon seven strips of
paper ; there may have been about 3600 eggs ; each of the strips
of paper contained about 512 eggs, which these moths had
attached during deposition. On the first strip all the eggs were
still tense, and furnished with the flat central depression ; forty
of them had retained their light yellow colour, five had ac-
quired a slate-grey colour, and all the rest appeared reddish-
brown. The second strip of paper bore eighteen bright yellow
and seven slate-grey eggs; all the rest were of a reddish-brown

IN THE SILK-WORM MOTH.

103

colour. The whole of the eggs appeared tense, and with a flat
depression in the middle ; eight reddish-brown eggs presented
themselves completely shrivelled. On the third strip there was
only a single light yellow egg, all the rest had acquired a reddish-
brown colour. None of these eggs were dried and shrivelled,
but the central depression was very strongly sunken in a great
many of them, so that it may be supposed that these eggs will
very soon become dried up. The fourth strip of paper contained
only four slate-grey eggs ; all the rest of its eggs possessed a
reddish-brown colour; only eleven of them were completely
shrivelled, but others were more or less approaching desiccation.
On the fifth strip of paper, I could count thirty light yellow,
tense eggs ; all the rest were of a reddish-brown colour, and only a
few of these were dried up ; on the sixth strip there were only
four light yellow, tense eggs ; all the rest were reddish-brown,
amongst which only a few had undergone complete desiccation
instead of the central depression. The seventh strip of paper
possessed only reddish-brown eggs, of which fourteen were
already completely shrivelled; but many others, to judge from
the deeply sunken central depression, were on the way to desic-
cation. Whether caterpillars will actually be developed from the
above-mentioned sixteen slate-grey eggs, which are still appa-
rently vitalizable, must be left to time to show.

If these investigations and experiments have as yet furnished
no definite result, the reason of this certainly is, that they
have not been repeated often enough ; at any rate Partheno-
genesis is now firmly established in Bombyx Mori, but never-
theless the history of the reproduction of this moth merits to be
further traced in this direction, as this precise object offers
so many suitable and convenient data for observations and
experiments.

104

CONCLUDING REMARKS.

Parthenogenesis, as it has been demonstrated by me in
Pysche Helix, and Solenobia clathreUa and Uchenella, in Bombyx
Mori and Apis mellificcu certainly occurs more generally in the
insect world, than the few examples hitherto discovered lead us
to suppose. This Parthenogenesis undoubtedly occurs in ac-
cordance with determinate laws, which have hitherto entirely
eluded our observation. In Nature, definite objects are probably
attained by Parthenogenesis, which we can only comprehend,
when we shall have learnt to know the life and actions of Insects
in general more exactly, than is at present the case. "What an
important signification Parthenogenesis has amongst the Bees,
will be seen at once, for without Parthenogenesis the whole
complicated ceconomy of the Bees, as prescribed by Nature,
could not exist at all. It is therefore now a task for the ento-
mologists, to search for further examples of Parthenogenesis in
the insect world. There are already indications enough, as to
how and where this remarkable mode of propagation is to be
sought after amongst Insects. From certain observations which
we find scattered in various entomological works, it appears,
that here and there Parthenogenesis dwells unsuspected, and
that by it the history of the reproduction of many insects is veiled
in mysterious obscurity.

Here belongs, amongst others, the statement of Leon Dufour,
that he has never obtained a male of Diplolepis gallce tinctorue*.

* See Leon Dufour, Recherches anatomiques et physiologiqu.es sur les
Orthopteres, les Hymenopteres et les Xeuropteres, in Menwires presenters par
divers savants a I'Acad. Roy. des Sci. de VInstitut de France, torn. vii. 1841,
p. 527. Here we find, " C'est un fait fort singulier, mais bien positif, que,
sur plus de deux cents individus du Diplolepis gallce tinctorice, nes dans mon
laboratoire de galles renfermees en bocaux, je n'ai rencontre que des femelles.
Malgre toute mon ardeur a rechercher des males, dont la dissection m'interes-
sait au supreme degre, je n'ai jamais pu en rencontrer un seul. Ce qui stimu-
lait encore davantage mon desir extreme d'etudier ce dernier sexe, c'est que
les nombreuses feinelles soumises a mon scalpel etaient dans un etat avance de

CONCLUDING REMARKS.

105

Of the genus Cynips, twenty-eight species are known, which,
according to Hartig's statement, are all destitute of males*.
Hartig has inspected nine or ten thousand of Cynips divisa, and
three or four thousand of Cynips folii, and found no single male
amongst them. Hartig has even collected Cynips folii for eight
years, and has never obtained anything but females of this Gall-
fly ; at the same time he saw these female Cynipidce proceed to
the deposition of their eggs immediately after their issuing from
the galls.

The reproduction occurring amongst certain of the lower
Crustacea, which it has been attempted to refer to Alternation of
Generations and nurse-formation, may also turn out on closer
investigation as true Parthenogenesis. As is well known, the
genus Apus amongst the Phyllopoda only presents females ;
Zaddach indeed has supposed that he discovered male indivi-
duals in Apus cancriformis-f, but I have called this statement in
question, on account of the want of positive proof J. Of the
Phyllopodous Limnadia gigas also, no male has yet been dis-
covered §. In Daphnia too, it appears not to be nurses but
female individuals which perform the business of reproduction
by Parthenogenesis ; for Lievin, who has compared with each
other, female Daphnice taken in copulation, and others which
were independently prolific, could not find the least distinction
between the two kinds ||. Of Polyphemus oculus} we as yet only
know female individuals ^f.

fe'condation, quoique je procedasse a leur vivisection immediatement apres
leur sortie de la galle."

* See Zweiter Nachtrag zur Naturgeschichte der Gallwespen in Germar's
Zeitschrift fur die Entomol. band iv. 1843, p. 397.

f See Zaddach, De Apodis cancriformis anatome, 1841, p. 53.

% See my Lehrbuch der vergleichenden Anatomie der wirbellosen Thiere,
1848, p. 495. note 8.

§ See Brongniart, Memoire sur la Limnadia, in Memoires du Museum
d'Histoire Naturelle, torn. vi. 1820, p. 89. " II reste un point tres curieux a
e'claircir dans l'histoire de ces animaux, c'est leur mode de generation ; il est en
effet fort remarquable que sur pres de mille individus que nous avons vus a
Fontainebleau, tous portoient des ceufs soit sur le dos, soit clans le corps."

|| See Lievia, Die Branchiopoden der Danziger Gegend, in the Neuesten
Schriften der Naturforschenden Gesellschaft in Danzig,himd iv. heft. 2, 1848,
p. 26.

IT See Junne, Histoire des Monocles qui se trouvent mix environs de Geneve,

106

CONCLUDING REMARKS.

Amongst the Mollusca also, phenomena occur, which indicate
the possibility of a Parthenogenesis : thus amongst others, Vogt
was able to observ e the commencement of development in the
eggs of a female Firola laid without fertilization, namely a seg-
mentation of the yelk proceeding to a certain extent*.

From these intimations, it appears that reproduction by Par-
thenogenesis is far from being sufficiently exhausted by my
investigations, and is still capable of receiving many an addition.
Even now, however, we may declare that the hitherto generally
admitted proposition of the fecundation theory, that the deve-
lopment of the eggs can only take place under the influence of
the male semen, has suffered an unexpected blow by Partheno-
genesis. It has indeed been attempted to avoid this, and hold
on to the old important proposition of the theory of fecundation,
by supposing that in many cases a single fecundation may act
through several generations : but much is not gained bv this new
proposition, as by it many of the phenomena occurring with
Parthenogenesis can by no means be explained. On the other
hand, it may appear too bold to assign already to Partheno-
genesis a definite position in the history of the reproduction of
animals, before it is thoroughly explored to a much greater extent
and in all directions. Victor Carus has attempted to bring Par-
thenogenesis into combination with the care of the brood (Neo-
melie'.and has established the proposition f: the female form must
be fertilized, and indeed by the male form, but for the develop-
ment of the latter! no repetition of the fecundation is required, —
the male germ developes itself in the manner of a bud or nurse.
This proposition, however, cannot be applied to all the cases of
Parthenogenesis cited by me : properly speaking, it only suits
the Bees ; in the other cases only females are evolved from the
unfecundated germs, and in Bom by x Mori, females and males
simultaneously in indefinite numerical proportions.

In Psyche Helix, Solenobia elathrella and Uchenella, in oppo-

1820, p. 146. u Quoique je ne doute pas qnil n'v ait des males dans eette espece
coinme dans les precedentes. je dois annoncer que dans le petit nombre d'indi-
vidus que j'ai trouTes. ou eleves. je n?en ai reeonnu aueun."

* See ^ogrs BUder aus dem Thierleben, 1S52, p. 21 7-

t System der thierischen Morphologie, \>53, p. 2S0.

J Op. cit. p. 57-

CONCLUDING REMARKS.

107

sition to the Bees, the females after copulation will probably de-
posit those fertilized eggs from which only males are developed.

Hence it may happen that here and there in the open air we
find the male and female individuals living together by them-
selves, and separate from each other. With this, the observa-
tion of Zinke stands in perfect accordance*, that many Sac-
bearers only occur in separate sexes during their larva and pupa
state, and that where one sex is met with, the other may be
sought for in vain. A communication made to me by letter by
Heyden may also find an explanation by this : Heyden observed
in the genus Coccus that the males live in company separated
from the females, until they are perfectly developed.

The male individuals in the larva state probably lead quite a
different mode of life in Psyche Helix, and might in consequence
have hitherto escaped the observation of those entomologists
who hoped to find the caterpillars of the males of Psyche Helix
as Sac-bearers with a convoluted dwelling. For these assertions
of mine, which are only expressed as suppositions, a support
may be found in an observation which was made by Leon
Dufour. From a particular gall, he always reared nothing but
female individuals of the Hymenopterous insect Stomoctea, but
was much astonished when he obtained nothing but males of
this insect from the pupa of a Tenthredof.

* See Germar's Magazin der Entomologie, i. 1813, p. 31.

\ See Leon Dufour, Recherches, fyc, p. 528. To the observation that he
had only been able to obtain females of Diplolepis gallce tinctorial, he adds the
following interesting remark: — "J 'engage les entomologistes a nous faire
eonnaitre le male de cette espece, la plus grande de nos contrees. II serait
bien curieux de constater si les ceufs qui ne produisent que des males sont
tous pondus dans une espece de galle, et ceux des femelles dans une autre.
Je puis citer a l'appui de cette question un fait digne de remarque. En juin
1833 j'obtins, des galles de la Scrophulaire canine, produites par YEulophus
Verbasci, un petit Hymenoptere du groupe des Cynipsaires, appartenant a un
genre nouveau, que ses mandibules pectinees m'ont fait appeler provisoire-
ment Stomoctea. II en naquit au moins une cinquantaine d'individus, mais
tous, sans exception, femelles. En juin 1834, je ne fus peu surpris de voir
eclore d'une chrysalide de Tenthredo, placee dans un verre clos, une quarantaine
d'individus de la meme espece de Stomoctea, tous du sexe masculin. Que
n'avons-nous pas a apprendre encore sur les Hymenopteres gallicoles et
pupivores, soit quant a la determination des especes, soit quant a leur genre
de vie et aux merveilles de leur organisation viscerale ! "

108

CONCLUDING REMARKS.

From these fragmentary statements it will be seen what a
wide field still stands open for the investigation of Partheno-
genesis, accompanied as it is by such extremely peculiar pheno-
mena ; in no case, however, will this portion of the history of
the reproduction of animals, enveloped as it is in so much ob-
scurity, allow itself to be quickly and easily cleared up ; for, as
regards Psyche Helix, for example, the entomologist desirous of
knowledge, and seeking after the males of this moth, must arm
himself with patience in order to arrive at the goal ; for if, in
this case, which is probable, Parthenogenesis has its hand in the
affair through several generations, as only a single generation of
this moth, the male of which has been sought in vain for the
last seven years, is produced annually, we should still have to
wait some years before a male generation at last makes its ap-
pearance, and reveals the mystery interwoven with this moth.

109

EXPLANATION OF THE FIGURES.

Fig. 1. Caterpillar-sac of Psyche Helix, Sieb., seen from the side.

Natural size, b, opening which has been left by an escaped
Chalcis.

Fig. 2. The same sac with the caterpillar; «, aperture which the
caterpillar always leaves in this spot during the enlargement
of its sac.

Fig. 3. The same sac seen from above ; a, as in the preceding figure.
Fig. 4. Full-grown caterpillar of Psyche Helix. Natural size.
Fig. 5. Female pupa of Psyche Helix. Natural size.
Fig. 6. Sac with caterpillar of Psyche Helix. Enlarged, a, as in
fig. 2.

Fig. 7. Caterpillar of Psyche Helix. Enlarged.

Fig. 8. Maggot-like female of Psyche Helix. Natural size.

Fig. 9. The same enlarged. By transmitted light the urinary vessels
appear black under the microscope, and not yellowish-white
as by direct light, c, head; d, a portion of the urinary
vessels shining through the integument.

Figs. 10, 11, 12. Three figures copied from Reaumur' s Memoir es,
torn. hi. pi. 15. figs. 20-22. Enlarged sacs of Psyche Helix,
which Bazin found upon sandstone in the vicinity of the
Hermitage d'Estampes.

Fig. 13. Chalcis nigra, Koll., from Psyche Helix. Natural size.

Fig. 14. The same insect enlarged.

Fig. 15. Caterpillar-sac of Psyche Planorbis, Sieb., seen from above.

Natural size. a, spot in which the walls of the sac are
deficient, as in fig. 2.

110

EXPLANATION QF THE FIGURES.

Fig. 16. The same sac from the side.

Fig. 17. The same sac seen from below; a, as in fig. 15.

Figs. 18, 19. Sac of Helicopsyche Shuttleworthi, Bremi. Natural size.

Fig. 20. The same sac seen from above, enlarged.

Fig. 21. The same seen from the side, enlarged.

Fig. 22. The same seen from beneath, enlarged.

Figs. 23, 24. Valvata arenifera, enlarged and copied from Lea.

Supplementary Observation. — At my last visit to Zurich I saw in
Bremi' s collection the cases of a third larger species of Helicopsyche,
which Bremi obtained from Shuttleworth and has named Helicopsyche
Colombiensis. These cases come from Puerto-Caballo ; they have a
transverse diameter of 1-^ lin. and a height of 1^% lin. Rhenish, and
are manufactured out of comparatively very coarse, rusty-brown stones.
With regard to Helicopsyche Shuttleworthi, Bremi informed me, that
the cases of this Phryganidous insect have now been found also on the
Lake of Geneva.

PRINTED BY TAYLOR AND FRANCTS,
RED LION COURT, FLEET STREET.

SIEBOLD an PART HKNOGKNESIS

London: Published, John-Yan Voorst, l857 .

Date Due

L. B. CAT. NO. 1137

QH467.S57

scm

ill

in

^ r^O? 00061 7790

a true parthenogenesis in moths and b

Science QH 487 . S57

Siebold, C. Th. E. von 1804-
1885.

On a true parthenogenesis in
moths and bees

cimi*ii*ii*ii*ii*im

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