August, 1921 



GLEANINGS IN BEE CULTURE 



489 



enough to depress the lip. In the flowers of 

 various members of the pea family, such as 

 peas, beans, clovers, etc., the stamens are 

 inclosed in the keel, which under the weight 

 of sufficiently heavy insects is depressed, 

 thus exposing the pollen. Small insects, how- 

 ever, can not usually effect this depression. 

 The closing of diurnal flowers at night and 

 nocturnal flowers by day is a protection 

 against unbidden guests, as well as against 

 rain and dew. 



Only the general methods of protection 

 and a few of the special contrivances are 

 described in this article. Each plant has its 

 own relation to these problems, either seem- 

 ing to bid them defiance or exhibiting some 

 peculiar and beautiful adaptation which 

 renders the study of the problem peculiarly 

 fascinating. Even these plants which seem 

 defiant usually have their own reason for 

 this apparent immunity. 



Ithaca, N. Y. 



THE poet 

 Horace said, 

 "Even if 

 you drive out 

 Nature with a 

 fork, slie will 

 come back. ' ' 

 When green- 

 house men first 

 put glass over 



their cucumber vines they discovered that, 

 tho they kept out the wintry blasts and the 

 consequent low temperatures, they had at 

 the same time and by the same means shut 

 out the vitalizing agencies for pollination 

 that Dame Nature had set to guard the 

 perpetuation of the plant race. 



So growers of early vegetables under 

 glass soon learned to set hives of honeybees 

 under the glass, along with the vines, thus 

 doing away with the tedious and costly 

 hand-pollination. That was one step back 

 to nature again, to be sure; but, altho help- 

 ful to the young pickles, it proved very de- 

 structive to the bees. Inasmuch as it is 

 vital to the greenhouse owner, that his 

 vines be freely visited by the flying bees, it 

 will at once readily appear, that it may not 

 be sufficient merely to have bees in green- 

 houses, but to have bees visiting the flowers 

 of the cucumbers while the blossoms are 

 open. Therefore it is very important to de- 

 termine the conditions most conducive to 

 the flight of the bees while they are under 

 glass, and the best means of getting full 

 efficiency from them. It is a question of 

 dollars and cents. It seems to be one also 

 of dollars and sense! For it is an axiom 

 with cucumber growers in greenhouses that 

 "Cukes from little pickles grow; and no 

 bees, no pickles setting." In a subsequent 

 article we shall try to show some of the 

 difficulties experienced in getting fullest ef- 

 ficiency from the bees under glass in the 

 spring of 1920. The present interest centers 

 in some observations made during the latter 

 part of March of the year named, regard- 

 ing the relation of temperatures to nectar- 

 aecretion. 



All the temperatures here recorded were 

 taken at hive level in the greenhouses, that 

 is, about two feet from the ground. They were 

 taken by the best tested thermometers, the 



NECTAR SECRETION 



Some Obser'vations on the Relation 

 Bet^ween Temperature and Nectar- 

 secretion in Greenhouses 



By E. G. Baldwin 



night records 

 being taken 

 from Bristol's 

 recording ther- 

 mometers. The 

 notes were made 

 daily, often 

 twice daily. It 

 was the aim to 

 mark the mini- 

 mum temperature of the preceding night, 

 the actual temperature at the time of 

 observation, the rapidity of the rise or 

 fall in temperature, the amount and kind 

 of nectar in the nectaries of the blossoms, 

 and the amount of sunshine then and 

 during the time just preceding the observa- 

 tions. The nectaries of the blossoms exam- 

 ined were pulled apart, and the fleshy nec- 

 taries exposed at the base of the anthers, in 

 the bottom of the flower-cup where the pet- 

 als join the calyx. By means of a double 

 hand-lens it was easy to note the presence 

 or absence of nectar. While the method of 

 thus examining the nectaries was not math- 

 ematically exact, it is believed that the eye 

 could detect whether the nectar was more 

 or less abundant at the time of the exami- 

 nations, and whether it was dried down into 

 crystals, sugary and white, or still liquid 

 and oozing out of the nectaries; for the nec- 

 tar in the cucumber blossom, under right 

 conditions, is sufficiently abundant and co- 

 pious to allow one to discern between dried- 

 down sugar crystals or freshly exuding nec- 

 tar; also the relative abundance of the lat- 

 ter. Bee-activity about or on blossoms also 

 afforded a criterion on nectar secretion. 



The observations were begun March 10, 

 1920, and ended March 31 of the same year. 

 Some were taken in greenhouses with high 

 roofs, and others in the ranges where roofs 

 were exceedingly low; sometimes the vines 

 were low and the aisles open; in other 

 houses and at other times the vines were 

 thick and heavy, making narrow and inter- 

 cepted aisles of tendrils and vines. 

 Notes on Temperatures, Amount of Nectar, 

 and Activity of Bees. 



March 10. — Plant A. — 8:30 a. m., temp. 72°F. 

 Minimum on night previous 60°F. Bees just set 

 in and not flying very well. Plants small and nec- 

 tar not abundant. Bees worked better in Plant X 

 in the afternoon than in the forenoon. 



