203 



At the time of the examination there were several 

 thousand Duchesse trees, eight, ten and twelve 

 years old, in full bloom, in close proximity to other 

 varieties which are not so ur.fertile. The Duchesse 

 trees were what gardeners call "one sheet of bloom. 

 The opm on of all present seemed to be, that so 

 much "bloom" must be very exhaustive. 



Mr. Thos. p. James, Botanist of the Pennsylva- 

 nia Horticultural Society, examined the flowers very 

 carefully with strong lenses, and said they were (as 

 compared with flower.'' of other varieties) very weak 

 in their organization, although apparently perfectly 

 hermaphrodite ; that the stigmas were evidently 

 feeble, the pollen li;vited in quantity, and the en- 

 tire flowers in a low oiate of vitality. 



The season was very unfavorable — cold and wet 

 — but the flowers examined had not, at that time, 

 been seriously injured. 



A large quantity of the Duchesse blossoms were 

 examined very minutely by Prof Horatio C. 

 Wood, Lecturer on Botany in the University of 

 Pennsylvania, under the microscope, and I have 

 much pleasure in appending his very acute observa- 

 tions upon this deeply interesting subject. I trust 

 that pomologists will not le' the matter stop here, 

 but t hat they will discuss the best method of avoid- 

 ing an excess of weak flowers on fruit trees, — or, 

 rather, the best means of producing a proper quan- 

 tity of string, well-organized and well developed 

 fruitful blosssoms. 



PROF. WOOD'S REPORT. 



I have examined the blossoms of the Duchesse 

 d'Angouleme pear. They are certainly sexually 

 perfect^ with both the male and female organs ap- 

 parently normal to the naked eye : but with the 

 microscope I find both the gynaecium and andrge- 

 ciuni (to use a medic 1 phrase) suffering from general 

 debil ty. Thus, the anther eel s, externally, apptar 

 to be well developed, large and finely formed ; but 

 they contain scarcely one-third as much pollen as 

 similar organs of more fruitful varieties. It seems 

 to me, further, that the pollen grains themselves 

 are not so well developer^, nor so crowded with 

 granules or fovilla3. In the same way the female 

 organs are defectively organized. For instance, the 

 stigmas are not so large, and the little papillae, 

 which secrete the so-called stigmatic fluid, are not 

 nearly so numerous, nor pronounced as in the flow- 

 ers of neighboring trees. 



In my own mind there is not much doubt but 

 that these evident marks of the want of vigorous 

 sexual development have a deeper meaning than 

 appears at first glance. What if there are compar- 

 atively few pollen grains ? Providence has so pro- 



vided that the great mass of the pollen is superflu 

 ous, and ordinarily is wasted. Surely the mere ab- 

 sen :e of a part of this superfluity would not produce 

 the barrenness you complain of. It seems to me 

 highly probable that the appreciable want oi' sfrenfyfh 

 is associated with a similar, but less apparent, de- 

 gradation as regards qiinh'f}/ ; and that there is a 

 consequent want of power in the germinal matter, 

 both of the pollen and ovary, which is the real cause 

 of the sterility. If this explanation be not the cor- 

 rect one, I know of no otl^er. 



Havin thus made a diagnosis in the case, the 

 next step is, if possible, to di cover the cause of the 

 condition, so as to remedy it, if practicable. Is it 

 not probable that the source of the trouble is to be 

 found in the excessive production ofhlnssoms, which 

 this variety of rear is notoriously addicted to ? Of all 

 the various life-functions of the plant, the process of 

 seed-producing is, par excellence^ the exhaustive one. 

 It is well known how it often cripples, or even kills, a 

 previously vigorous tree. Further, the period du- 

 ring the reproductive procrss, the worst for the 

 plant, in which it eats up its life-capital fastest, is 

 that in which the blossoms are perfected, the pollen 

 shed, and the ovule impregnated. 



The reasons for 'his nre obviously two-fold. In 

 the first place, the production of very highly-vital- 

 ized matter rapidly exhausts both the plant and the 

 animal. Thus the conse tuences of an ext^essive 

 production of semen in the animal are notorious. 

 Now it is at the period alluded to that we have the 

 greatest elaboration of costly products in the flower. 

 Not only are the ovaries, with their contained ovules, 

 and the anthers with their myriad pollen grains, 

 rapidly developing, but the sepals and petals, 

 with their numerous oil glands, are aiding in the 

 prodigal waste of the strength the plant, mayhap, 

 has been years in obtaining. It is readily seen that 

 after impregnation, during the slow, gradual produc- 

 tion of the fruit and seed, we have no such sudden 

 burst of life activity. 



Again, at this p riod, there is, probably, the 

 greatest loss of nitrogenized principles that occurs 

 during the life of the plant. When the leaves are 

 about to die their nitroge. ized contents return to 

 the stem and roots, showing the great value to the 

 plant of these principles. The seeds, to be sure, 

 contain much nitrogenized material ; but then there 

 are comparatively few of them perfected. Not so 

 with the pollen. You can often see it, almost, 

 making little clouds in the air, or dusting thickly 

 the surface of ditches with its countless granules, 

 and each of these is literally gorged with the most 

 highly vitalized nitrogenous material the plant can 



