1910 



GLEANINGS IN BEE CULTURE 



To my great surprise, not a single diseased 

 cell could be found in the hive! 

 Marengo, 111. 



[This is all very interesting. We should 

 be glad to get reports from one or more of 

 the York State inspectors who have had a 

 large experience with this disease.— Ed.] 



EUROPEAN FOUL BROOD. 



Will the Disease Reappear^Among Dr. Mil- 

 ler's Dees? 



BY F. H. HARVEY. 



I have just been reading Dr. Miller's arti- 

 cle in the Dec. 1st issue on his experience 

 with black or European foul brood. I note 

 what he says about shaking the bees direct- 

 ly on full sheets of foundation without put- 

 ting them on starters first. I have tried it, 

 and have had the black brood reappear in a 

 good many cases. I have also had it reap- 

 pear when swarms from diseased colonies 

 were hived on starters, both when given the 

 partly filled section- super and when given 

 an entirely new one. This is most apt lo oc- 

 cur when the bees are dark or have a queen 

 that is not first class. 



If Dr. Miller's experience is like mine he 

 will find more or less of his treated colonies 

 showing diseased larvae early next spring. 

 If the colonies are reasonably strong, and 

 the queens good young Italians, the disease 

 will disappear from most of the colonies for 

 the rest of the season as soon as honey comes 

 in freely. 



Regarding the time of day for treating dis- 

 eased bees, I have found early morning, as 

 soon as it is light, the best. The bees are 

 easily handled, and do not crawl into one's 

 clothing as they do in the evening. 



Battle Creek, Mich., Dec. 6. 



[This seems to carry out Dr. Miller's (or, 

 rather, Alexander's) theory that the source 

 of the trouble may reside in a poor queen. — 

 Ed.] 



THE DEVELOPMENT OF POLLEN. 



Insects Can Not Stimulate Flowers to 

 Develop More Pollen. 



BY JOHN H. LOVELL. 



On p. 677, Nov. 1, a correspondent raises 

 the following query: 



Now, there is one point in connection with the pol- 

 lenizing of flowers that I have never seen mentioned. 

 The greenhouse men used to scatter the pollen by 

 hand, and get some fruit; but now they generally keep 

 bees, and get much better results than by hand work. 

 Now, is not this the result of the bee working, or ex- 

 ercising the glands of the flower in some way? . . . 

 Who knows but that this moving or exercising of the 

 stamens and pistils causes the pollen ducts to put forth 

 extra efforts? . . . I should like the opinion oi some 

 scientific bee-keeper on this subject, as I think it a 

 profitable one for discussion. 



A brief outline of the development of the 

 grains of pollen will show that this is impos- 



sible. The pollen is not secreted by ducts, 

 and the number of grains in each anther is 

 determined long before it is visited by in- 

 sects. The manner in which they are form- 

 ed is as follows: 



At first ttie anther is a mass of small homo- 

 geneous cells, alike in size and kind, cover- 

 ed by an epidermis. Soon it becomes faint- 

 ly four-lobed in cross- section, and a central 

 strand of tissue is differentiated to form the 

 connective or common base. In the mature 

 anther these four lobes become reduced to 

 two, each containing two cavities partially 

 or wholly united. Each of the four lobes of 

 the nascent anther is a center for the pro- 

 duction of pollen. The layer of cells direct- 

 ly under the epidermis (the hypodermal 

 layer) produces the pollen grains. The num- 

 ber of these cells varies greatly in different 

 species of plants, from 1, 2, or 3, to many. 

 This plate of cells, of which there is one to 

 each of the four lobes, is called the arche- 

 sporium. By a series of divisions these cells 

 rapidly increase in number; and the outer 

 and inner layers are differentiated into walls 

 for the protection and nourishment of the 

 primary central layer, which either directly, 

 or usually by three or four divisions, gives 

 rise to the pollen motner-cells. 



The motner-cells increase greatly in size, 

 and stain differently from the tissue by 

 which they are surrounded. Their walls 

 thicken, become rounded, and tend to sepa- 

 rate from each other. The time required 

 for the development of the pollen mother- 

 cells io ^rr,m. one to two weeks. 



Eich rn ■•iif f evil divides into four cells or 

 gvA U3 f pn'l:-n. [-i cue monocotyledons 

 {grAsscsi, scd^s, li ips, and orchids) the 

 mother-ceI( d> les lirst into two cells, and 

 then each O'- ..L-v^i^j hemispheres divides 

 again to form the tetrad of pollen grains. 

 In the dicotyledons (buttercups, roses, 

 clovers, daisies, and deciduous trees) the 

 nucleus of the mother-cell divides at once 

 into four nuclei, and the cell-walls are form- 

 ed later. Deviations from the number four 

 occasionally occur, and instances are known 

 of 2, 3, 5, 6, 7, and 8 pollen grains arising 

 from a single mother-cell. 



The wall of the pollen grain is a delicate 

 structure which soon becomes differentiated 

 into two layers. The outer layer is often 

 beautifully marked in various patterns, and 

 beset with spines and warts. At maturity 

 the pollen-grains become a powdery mass, 

 and the four cavities are reduced to two by 

 the breaking-down of the partition wall in 

 each anther lobe. In rhododendron and 

 some other genera the four grains of the te- 

 trad remain adherent, while in the orchids 

 all of the grains are bound together in pack- 

 ets called pollinia. 



The anthers open, or dehisc, in various 

 ways, and the pollen either falls out or is 

 forcibly expelled, or adheres to insects, birds, 

 or other visitors to the flowers. 



While only a very brief outline has been 

 given of the development of the pollen 

 grains, it is evident that movements of the 

 stamens and pistils by bees can not increase 



