762 



GLEANINGS IN BEE CULTURE. 



Sept. 1 



spend a few weeks at Medina, in the apia- 

 ry of The A. I. Root Co., studying- the par- 

 thenogenesis of the bee, and I esteem it a 

 pleasure to record in Gleanings my ap- 

 preciation of the never-failing kindness of 

 all with whom I came in contact. 



The word "parthenogenesis," in the 

 sense in which it is now used, was first 

 used by Prof. Carl Th. Ernst von Siebold, 

 in his valuable work on the parthenogene- 

 sis of butterflies and bees (1856). Before 

 that time no word had been coined to ex- 

 press the production of individuals from an 

 unfertilized egg; and, in fact, very few per- 

 sons believed that it was ever possible. V. 

 Siebold should be given credit equal to that 

 of Dzierzon for the theory of parthenogene- 

 sis, for it was only after the research of 

 years, carried on by the German scientist, 

 that any valuable and acceptable proof was 

 put forward. 



In the development of unfertilized eggs 

 into adult animals, but three conditions are 

 possible; and we find in the animal king- 

 dom examples of each. These conditions 

 are, 1, the production of males onl}'; 2, the 

 production of females only; 3, the produc- 

 tion of both sexes alike. A variety of 

 names have been given to these different 

 cases by zoologists, but it will not aid in 

 any way to fill up this article with a lot of 

 words of Greek derivation. Let us now 

 take up each of these cases briefly. 



1. Very little need be said in this place 

 concerning the production of males from 

 unfertilized eggs, since that is the kind of 

 parthenogenesis with which the readers of 

 Gleanings are probably most familiar. 

 Since Dzierzon first announced his discov- 

 ery to the world, many persons have at- 

 tempted to prove that drone eggs are fertil- 

 ized in the case of eggs laid by a fertile 

 queen; but so thoroughly has the theory 

 been proven by von Siebold, recently by 

 Prof. Weismann and his pupils, Paulck and 

 Petrunkewitsch, and by many others, that 

 but little faith can be put in the observa- 

 tions and conclusions of Perez, Dickel, and 

 others with like theories. We can safely 

 assert that all drones are produced from 

 unfertilized eggs, and all workers and 

 queens from fertilized eggs, since all au- 

 thentic scientific investigations assert the 

 truth of the statement. The same is true 

 for the males of many other insects, which, 

 with the bee, are included in the group 

 of social Hyvieywptera. "Wasps, hornets, 

 and ants furnish examples of the same kind 

 of parthenogenesis. 



2. Examples of females produced from 

 eggs which do not receive the male cell are 

 found in certain small and rare butterflies. 

 It is evident that this form of parthenogene- 

 sis gives to a rare species a much better 

 chance of surviving, since it is never neces- 

 sary for a male and female to meet. In the 

 case of the bee, copulation is necessary for 

 the production of the queen, the individual 

 that has most to do with the propagation of 

 the species; but in these cases copulation is 

 never necessary. 



3. The last class of parthenogenesis, that 

 in which both males and females are pro- 

 duced without union of the two sexes, af- 

 fords some of the most interesting facts in 

 all natural science. Volumes could be 

 written — in fact, volumes have been written 

 — concerning the difterent ways in which 

 animals having this power behave. The 

 best known and most interesting cases 

 which fall under this group are those of the 

 plant-lice. Aphides, and water-fleas. The 

 small wheel animalcules, or rotifers, so 

 abundant in all pools of water, also show 

 this phenomenon frequently. Let us now 

 examine one of the plant-lice more careful- 

 ly, as an example of this group of our class- 

 ification. In the spring there hatches from 

 an egg which has lived over winter a wing- 

 less female plant-louse, and no males are 

 seen at this time of the year. This female 

 soon produces numbers of young offspring 

 which come from their mother in a living, 

 active condition, and these, in turn, soon 

 produce more winged or wingless individu- 

 als in the same way — a considerable number 

 of generations appearing during the course 

 of a single summer. Finally, when the 

 unfavorable conditions of autumn come on, 

 there appears a generation consisting of 

 males and females. The individuals of this 

 generation mate, and the females lay fertil- 

 ized eggs which live over winter and begin 

 the cycle again the following spring. In 

 different kinds of plant-lice this cycle may 

 be modified by the migration of the winged 

 generation to some other species of plant, 

 for each plant has its own kind of plant- 

 louse! and then somewhere else in the cycle 

 another winged generation will appear, and 

 they will all return to the original kind of 

 water-plant. 



A cycle similar to this takes place in many 

 of the little water-fleas, which can readily 

 be seen if you dip up in a glass vessel some 

 water from a stagnant pool. If you let this 

 vessel of water stand for a day or two you 

 may see collected on the sides little patches 

 of what appears to be slime, but which on 

 examination with a good lens turns out to be 

 one of the most beautiful objects in all na- 

 ture — a colony of rotifers. Many of these 

 also have a cycle similar to that which has 

 been so briefly described for the plant- 

 lice. 



Besides these cases, parthenogenesis has 

 been described for a couple of beetles, for 

 several flies, for some spiders, for the ani- 

 mals which cause liver-rot in sheep, and 

 doubtfully for several other groups in the 

 animal kingdom. It was also supposed a 

 few years ago that it was not of uncommon 

 occurrence among plants; but of late years 

 it is disproven for most of the supposed 

 cases, and to-day is held for but three plants. 

 It is thus evident that parthenogenesis is of 

 quite common occurrence in many groups of 

 animals besides bees; in fact, the develop- 

 ment of males only is probably character- 

 istic of the least modified type of this, 

 strange ability. 



Philadelphia, Pa. 



