196 



THE AMERICAN BEE JOURNAL. 



[March 



Schiner, reported to the imperial zoological-botani- 

 cal society in February, 1865, it hardly seems to 

 differ from the genus heteropeza Winnertz. Repro- 

 duction takes place by means of germs. From 

 seven to ten of these arise out of the accumulated 

 plastic material in the body of the "mother-larva," 

 and develop to "daughter-larvae." The former is 

 thereby gradually destroyed, and the progeny tears 

 her skin and passes out. After three or five days 

 the same process of germination begins in the new 

 larva, and this continues from August to June, 

 when all the larvas of the last generation simul- 

 taneously pass into the pupa state. After three or 

 four days the perfect insect, a small reddish-brown 

 fly, emerges from the pupa. The correctness of 

 these observations was afterward verified by 

 v. Baer and v. Siebold, and Professor Alexander 

 Pagenstecher, of Heidelberg, observed the same 

 thing in another species and accurately described 

 it.* 



Metagenesis, with mature individuals as nurses, 

 is exemplified among the arthropods by the aphides. 

 As early as the middle of the last century, Charles 

 Bonnet f had already communicated exact observa- 

 tions on the peculiar and remarkable mode of re- 

 production of the aphides, (plant-lice.) These well- 

 known enemies of our gardens and green-houses 

 cover the leaves, shoots, and branches of certain 

 plants in thick swarms, and defy all our exertions 

 to get rid of them by their extreme fecundity. 

 During the summer months there is a series of nine 

 or ten generations of fully-formed but sexless ani- 

 mals, or nurses, which bring forth living young 

 without fecundation, and even without the presence 

 of the male. Embryos are formed immediately 

 from germs, which do not show the structure of 

 true ova. Thej' separate from peculiar tubes (ger- 

 minal tubes) and develop in the body of the mother. 

 In autumn the next to the last generation produces 

 sexually developed males and females, which really 

 cohabit. As in most insects, the male then per- 

 ishes, while the female lays eggs, which hibernate 

 ;ind produce a new race of nurses the following 

 spring. The anatomical examination of these ani- 

 mals, which was first undertaken by v. Siebold, and 

 afterwards confirmed by Leidig, shows that the 

 viviparous individuals are well developed, and re- 

 semble the oviparous females of the last fall gene- 

 ration, but that they are sexless nurses, because 

 they lack the seed-bladder belonging to all female 

 insects, and are, therefore, incapable of receiving 

 the male seed. 



All the phenomena of alternate generation were 

 also called "Parthenogenesis" by the excellent 

 English anatomist, Richard Owen, in 1849. \ and 

 this name, although somewhat inappropriate, was 

 generally received on account of its euphony. 

 When, however, the surprising discoveries of the 

 last few decades put in question the theory that 

 " every true egg cannot be developed into a new 

 individual, (animal or plant,) unless it has been 

 previously fructified by the action of the male 



* Zeitschrift fur wissenschaftliche Zoologie, xiv, p. 400. Fur- 

 ther investigation of this subject is communicated by Leuckart, 

 in Troschel's Archiv., year XXXI, No. 3. 



}Traite d'lnsectologie, tome I : Paris, 1845. 

 On Parthenogenesis; a discourse introductory to the Hun- 

 terian Lectures on generation and development for 1849. Deliv- 

 ered at the Royal College of Surgeons of England : London, 1849. 



seed," it seemed expedient to confine the term 

 "parthenogenesis" to the new phenomena. In 

 this sense it was first used by the ingenious founder 

 of this important new theory, the distinguished 

 zoologist of the Munich University, Karl Theodor 

 v. Siebold, in his paper on 'True Parthenogenesis 

 in Butterflies and Bees ; an Essay on the Reproduc- 

 tion of Animals. Leipsic, 1856." 



Parthenogenesis or virginal generation, according 

 to Siebold, comprises "those phenomena which 

 demonstrate that true ova may be developed into 

 new individuals without the fecundating interven- 

 tion of the male seed." 



There is no want of observations of former times 

 according to which the eggs of virgin insects were 

 said to have produced new individuals, but they 

 were considered erroneous. Zoologists doubted 

 that they were made with proper care, and at- 

 tempted to explain them in different forced ways, 

 finally classing them under metagenesis. Among 

 them are the communications of De Geer on the 

 psychides, and of Herold on the silk-worms. In 

 1845 the celebrated apiculturist, K. Dzierzon, a 

 Catholic priest at Karlsmarkt, east of Brieg, in 

 Prussian Silesia, emphatically maintained in the 

 "Bienenzeitung," p. 113, that the eggs from which 

 the male bees or drones originate are produced and 

 developed by the sole inherent power of the mother 

 bee without the action of male seed. This view at 

 first seemed simply incredible to apiarists; they 

 supposed that he had either deceived himself or 

 intended to mystify others. But when Dzierzon 

 reiterated his statement he was severely attacked, 

 and the dispute continued for a long time. 



Until 1852 Dzierzon stood alone against their 

 attacks, but undaunted, unconquered. He could 

 fall back on the experience of many years. Every 

 one knows that there are queens which produce 

 only male progeny or drones, and never lay an egg 

 from which mature females, queens, or stinted 

 females, workers are developed ; that there are 

 others which may lay female eggs for a time but 

 afterward become like the former, and that finally 

 there are worker-bees which lay eggs, which give 

 birth only to male individuals. 



Among the first class Dzierzon frequently found 

 bees whose wings were lame. They were thus pre- 

 vented from making their hymeneal flight from 

 which they would otherwise have returned impreg- 

 nated. Other queens, which laid male eggs from 

 the beginning, were hatched either very early or 

 very late in the year, at a time when there were 

 either no more or only very few drones left, so that 

 their flight was in vain. Queens which at first laid 

 normal eggs and. afterward produced only drones 

 were older individuals, whose stock of seed had be- 

 come gradually exhausted. Worker-bees, which 

 sometimes lay eggs and never have any other than 

 male progeny, have never been and are indeed in- 

 capable of being impregnated. From these facts 

 Dzierzon concluded that impregnation was unneces- 

 sary to the production of drones. That in com- 

 mon normal generation, where the queen returns 

 impregnated from her flight, the drones are devel- 

 oped from unfecundated eggs, i. e., from those 

 through whose micropyles the spermatozoa have 

 not penetrated, is proved by Dzierzon from the fol- 

 lowing fact: After the introduction of the Italian 



