8 



AMERICAN BEE JOURNAL 



January 



but results in a flow of water from 

 within the plant, at that point. 



The absorbing roots of plants show 

 another result of this physical prop- 

 erty, osmosis. They are not water- 

 proofed; water is continuous through 

 them, from the thin layer in which 

 it occurs about particles of the soil, 

 to the water, which composes a 

 great part of the weight of the proto- 

 plasm within the cells. This sap of 

 the root cells contains dissolved 

 sugar and other osmotic substances. 

 Osmotic absorption by the roots re- 

 sults in a pressure of several atmos- 

 pheres. Thi| pressure, passed from 

 cell to cell, gives the crispness to fresh 

 celery. Its loss, through evaporation 

 from the leaves, results in the loss 

 of this crispness, or wilting. 



When evaporation is slight, as in 

 a saturated atmosphere, water ex- 

 udes at the surface through pores 

 such as occur at the tip of a young 

 grass or clover leaf. Water pores of 

 this sort are common. They are re- 

 garded as pressure-valves by many 

 botanists. The water that they elim- 

 inate is usually filtered by the proto- 

 plasm that it passes through, which 

 does not allow the passage of sub- 

 stances dissolved in the cell sap; but 

 some plants which grow where they 

 absorb very "hard" water pass lime 

 salts out through their water pores to 

 such an extent that they are encrust- 

 ed with lime as the water evaporates. 

 The safety-valve elimination of wa- 

 ter under strong internal pressure 

 and lessened normal evaporation is 

 hardly to be called excretion or se- 

 cretion; the extruded water is neither 

 by-product nor manufactured output. 

 The elimination of lime appears to 

 be on the border line of excretion. 



Nectar is not merely water; if it 

 were its production would be more 

 easily understood. To the taste it is 

 sweet, to the sense of smell is is 

 often fragrant; occasionally it is 

 poisonous; often it is somewhat col- 

 ored. Commonly it is very fluid, but 

 in the nectar-cups of poinsettia it 

 becomes very gummy. These proper- 

 ties come from substances — sugars, 

 volatile oils, poisonous organic com- 

 pounds — that were made by and in 

 the plant, and they differ in different 

 kinds of plants. Whatever bees or 

 ants may do in changing nectar into 

 honey, they do not entirely change or 

 remove these substances, and the 



rank brown honey of the drug store 

 is as easily run to its source as the 

 popular white clover honey, the dain- 

 tily flavored product of western al- 

 falfa, the aromatic acid honey of the 

 red raspberry, or the greenish prod- 

 uct of the sweet clover, with its deli- 

 cate vanilla-like aroma, the cumarin 

 source of which shows itself in an 

 occasional headache, much as the 

 minor organic constituents of some 

 honeys derived from the heath family 

 now and then prove seriously poison- 

 ous. 



A fluid that contains these organic 

 substances necesarily falls into the 

 catagory of excretions or secretions, 

 according as it represents waste or 

 usable material. As either excretion 

 or secretion, it is the product of spe- 

 cialized organs, glands, and its ap- 

 pearance marks these glands as in 

 action or performing their function. 

 Whatever else may be involved, this 

 depends upon the activity of their 

 protoplasm, or is controlled by it. 

 When this is killed, secretion or ex- 

 cretion stops. 



One result of the protean charac- 

 ter of protoplasm is its different be- 

 havior in different plants, different 

 organs of the same plant or different 

 phases of the activity of an individ- 

 ual cell. In either case it can per- 

 form its functions only between cer- 

 tain limits of environment, and it 

 performs them best somewhere be- 

 tween these limits. For each func- 

 tion and each condition there is 

 what physiologists call a minimum — 

 below which it is not carried on, a 

 ma.ximum — above which it has 

 stopped, and an optimum — or most 

 favorable. Just as in the efficient 

 working of a human factory, power 

 and raw materials are necessary, and 

 workmen must be onto the job, how- 

 ever favorable the other conditions of 

 manufacture may be. 



The secretion of nectar and the 

 storing of honey are consequently 

 not quite comparable; for the activi- 

 ties of the honey plant are concerned 

 with the first, and the activities of 

 the bee are concerned in the second, 

 though these are largely influenced 

 by what the plant is or is not doing. 

 This must be remembered always 

 when comparing such records of 

 honey storing as Mr. .Strong's careful 

 hive-weighings through a generation. 



All parte of plants are composed of individual cells flattened against one another. Tl 

 copied from Bonnicr's "Les Nectaires," exhibits a longitudinal section of a stamen 

 iimia bicolor. Magnified. 



At left (84) cross section of filament. 



This figure 

 in Col- 



Stomata on nectariferous tissue of Xanthoce- 

 ras sorbifolia. Greatly magnified. Copied 

 from Bonnier's "Les Nectaires." 



with Mr. Kenoyer's quantitative 

 measurements of nectar secretion. 



Nevertheless, the most favoring 

 conditions of nectar secretion and 

 honey storing agree in a number of 

 respects. Vigorous early develop- 

 ment of the plant puts it in condi- 

 tion to do its share of the work best; 

 whatever conditions may prevail dur- 

 ing what for most plants is a very 

 short part of the growing season, when 

 it is in bloom. Vigorous early develop- 

 ment of the hive bears the same kind 

 of relation to the final result. Early 

 honey must be stored before the bees 

 have reached the full strength of the 

 season, which may have something to 

 do with the fact that the bulk of the 

 harvest is gleaned from plants that 

 flower later or continue to flower for 

 a relatively long time. 



Mr. Strong's observations in Iowa 

 show that over half of the net in- 

 crease in honey storage, in southern 

 Iowa, is made in June, and over four- 

 fifths in June and July. These are 

 the months when the most produc- 

 tive nectar plants flower, and the 

 hives have reached the crest of their 

 speculative activity and are undergo- 

 ing division by that time. 



Physiological studies show that the 

 afternoon temperature for nectar se- 

 cretion is high — between 90 and 100 

 degrees Fahrenheit. Observation on 

 the hive shows that its workers are 

 at their active best in moderately hot 

 weather. Mr. Strong's 29-year aver- 

 age shows that over half of the av- 

 erage honey for the year is stored 

 when the daily maximum is between 

 80 and 90 degrees, and nine-tenths of 

 it is stored when the hig,< tempera- 

 ture of the day is between 80 and 100 

 degrees. Nectar is most abundantly 

 secreted, other conditions being 

 equal, in warm days following cool 

 nights; bees do not seem usually to 

 work more actively on such days, 

 though a record day for heather 

 honey in England began with a frost. 

 Damp air increases the quantity of 

 nectar, as of the expulsion of water 

 through water pores; but dull rainy 

 weather lessens or stops the activity 

 of the bees. 



Nuptial nectar is secreted chiefly 

 before or during the period of sexual 



