GLEANINGS IN BEE CULTURE 



development in the egg, which may be of 

 si:)ecial interest to the beekeeper. 



The vital processes which lake place in 

 the egg of the bee after it is laid, and by 

 which it becomes a larva, are as much a 

 mystery to the average beekeeper as are the 

 problems of human consciousness or the 

 extent of stellar space. It is to be feared 

 that to him an " egg is an egg," just as in 

 Wordsworth's much quoted lines in " Peter 

 Bell :" 



A primrose by a river 's brim 

 A yellow primrose was to him, 

 And it was nothing more. 



One of our leaders in science, a well- 

 known university professor, used annually 

 to quote to his classes the following lines 

 (and does yet, for all we know!) : 



Flower in the crannied wall, 



I pluck you out of the crannies; 



I hold you here, root and all, in my hand, 



Little flower; but if I could understand 



What you are, root and all, and all in all, 



[ would know what God and man is. 



This is surely a more reverent attitude 

 to take in the presence of the miracles of 

 Nature. 



It is not possible to know or understand 

 all that takes place in a living organism ; 

 but by patient investigation we can learn to 

 knoAV much, and this knowledge is of ines- 

 timable value, even altho it teaches us to 

 lecognize only the infinite extent of the 

 mysteries of Nature and the relatively infin- 

 itesimal extent of human knowledge. 



An investigation of the development of 

 the bee's egg of course brings to light many 

 interesting and curious facts. Among them 

 one of the most striking is the rate at which 

 development proceeds, or, rather, appears 

 to proceed, since we can judge the rate 

 only by what we can see, and we have no 

 means of valuing the amount of energy 

 required by the different developmental 

 processes. The whole course of embryonic 

 development may be divided into two pe- 

 riods: 1. That in which is pi'epared the 

 material required for the formation of the 

 embryo. 2. The actual visible construction 

 of the embryo from these matei'ials. 



The bee-egg, like every other egg, com- 

 mences its embryonic development as a sin- 

 gle "cell." This " cell " is the unit of struc- 

 ture in all living organisms, and for present 

 purposes it may be considered as a minute 

 portion of living substance, having the 

 power to reproduce its kind by self-division. 

 This cell is in the bee egg imbedded in the 

 yolk, which m.akes up the bulk of the egg. 

 the entire egg, of course, being enclosed in 

 a thin and tough membranous shell, the 

 " chorion." This single cell divides into two 



cells, these into four, and ?o on until a 

 considerable number are scattered thru the 

 yolk. Then these, still continuing to divide, 

 come to the surface of the egg and, "joining 

 hands," so to speak, form a layer all over 

 the surface of the egg, and this layer by a 

 further increase in the number of the cells 

 becomes a sort of skin, the " blastoderm." 

 The number of cells making up the blasto- 

 derm is several thousand at least. In regard 

 to their shape and arrangement, they may 

 be imagined as extremely minute paving- 

 stones. This stage is not reached until 

 about thirty hours aft-er the egg is laid — 

 much more than a third of the time required 

 for complete development, 76 hours. Dur- 

 ing the next fourteen hours the blastoderm 

 becomes folded lengthwise of the egg in 

 such a way that three layers of cells are 

 formed over the whole lengih of the egg 

 on its longer curved side. A number of 

 cells are also heaped up at the two ends of 

 the egg, and these last cell-heaps are des- 

 tined to form the entire stomach or " mid- 

 intestine " of the larva. This closes the 

 first period. The materials for the con- 

 struction of the embryo are now all pre- 

 pared and laid in the proper places. It is 

 important to note that the egg is now near- 

 ly two days old (44 hours"), and that all this 

 time has been consumed in the preparation 

 of the material. During the nest 32 hours. 

 Dame Nature gradually molds these mate- 

 rials into the form of a bee-larva. At 46 

 hours (Fig. VII.) the rudiments of the brain 

 and of the appendages — ^mouth parts (Md, 

 IMx, 2Ms) and legs (IL, 2L, 3L)— make 

 their appearance as rounded swelling's. The 

 mouth (Sto), the silk glands (SlkGl) and 

 the tracheas (Sp. — ) also show themselves 

 as pits or inpushings of the surface layer 

 (ectoderm). The remainder of the devel- 

 opment consists principally in the elabora- 

 tion and completion of the parts already 

 laid down as rudiments. 



The material required for formation of 

 the cells themselves, and the fuel necessary 

 to supply the energy expended by them in 

 their movements and subsequent metamor- 

 phosis into organs and tissue, is furnished 

 by the yolk, which gradually shrinks away 

 from the ends of the egg, and, later, from 

 its lower side. Finally the yolk becomes 

 enclosed by the mid-intestine (stomacli) of 

 the future larva and is then completely 

 digested. 



One of the first external evidences of 

 commencing development is the shortening 

 of the egg within the egg-sliell, and the 

 spaces left at the two ends of the eo'C be- 

 tween the egg and the shell, are filled with 

 a clear fluid. The es:g continues to shorten 



