30 QUEENSLAND AGRICULTURAL JOURNAL. [1 Jan., 1898. 
_ therefore, be not without profit to inquire—What is the purpose, from the 
point of view of this plant, served by bees in visiting its blossoms? This, it 
may be affirmed, is the pollination of the flowers and the conscquent fecundation 
of the ovules that their ovaries contain; and, not only this: under favouring 
circumstances cross-pollination and fertilisation as distinct from  self- 
fertilisation. This, again, suggests other questions. Is this pollination of 
service to the plant as a fruit-producer or otherwise? If so, is cross-pollina- 
tion a desirable end in itself ? : 
In entering upon this inquiry, one is confronted at the outset with the 
absence of any record of exact information, in the case of the orange, con~ 
cerning the nature of the means by which pollination as distinct from fecunda~ 
tion (the two constituting the fertilising act) is effected, as well regarding the 
relative values to the tree—as a fruit-producer—of the different methods by 
which this act might be consummated ; of such information, in fact, as we haye 
in the case of the pear, thanks to the exact and fruitful observations of Merton 
B. Waite.* On the other hand, very full information is available regarding 
the changes constituting the latter process in the individual flower that 
immediately result from contact of potent pollen with the stigma, and that 
succeed this fecundation of the ovules; W. Hofmeister, H. Schacht, and Dz. 
O. Penzig having each written very fully on the subject.+ 
It may be objected that as absence of seeds in the fruit, or their 
comparative absence, is an object that the orange cultivator should aim at, 
therefore the pollination of ihe flowers that results in seed formation is 
redundant, if not a harmful, act. But there exists little ground for concluding 
that any plant, much less the orange, can dispense with the act of pollination 
as a prior condition influencing the full development of its fruit. As M. B. 
Waite has remarked, in the case of some plants, the English cucumber, for 
instance,{ it is thought to be true that the fruit without seeds develops when 
no pollen is applied. ‘‘ Several times (he writes) in my own work (on pear 
blossoms, H. T.) flowers were emasculated and not pollinated, and with two 
exceptions failed eyen to set fruit. The two exceptions (he proceeds) 
occurred with the Le Conte and Heathcote. A few fruits set and were counted 
on the Le Conte, but none reached maturity. Three fruits set on the Heath- 
cote tree at Geneva, and one of these developed. It was just like the self- 
pollinated fruits. This, of course (he adds), may have been accidentally self- 
pollinated before the flower opened.’§ This necessity for the act of 
pollination to precede fruit formation, the existence of which may be 
reasonably inferred, is intelligible when one considers, as pointed out by 
Focke, and as remarked also by Waite, that there are two actions of the, 
pollen to be considered, and not one only—the one consisting in the fecunda-~ 
tion of the ovules (seeds); the other in a stimulating action on the ovaries 
(fruit) that results in their development.|| 
The act of pollination then being essential to the formation of fully 
developed fruits, it may now be considered, whether in the case of the orange 
self-fertilisation—in other words, the setting of the fruit without the inter- 
vention of external agencies or rather of pollen derived by their instrumentality 
from a different horticultural variety or from an individual plant of the 
same horticultural variety, but grown under different conditions; or cross- 
*M. B. Waite: ‘‘ The Pollination of Pear Flowers,” Washington, 1894. : 
+ Cf. W. Hofmeister: “ Neuere Beobachtungen iiber Embryobildung der Phanerogamen,” in 
Pringsheim’s Jahrbiicherr fiir Wissenschaftl. Botanik, vol. i., Aurantiacez, pp. 94-5, Berlin, 
1858; H. Schacht: ‘‘ Ueber Pflanzen-Befruchtung,” 1858, pp. 209-216; and O. Penzig: ‘‘Studi 
Botanici sugli Agrumi e sulle Piante Affini,” pp. 83-98, Rome, 1887. 
+ Munson : ‘‘Secondary Effects of Pollination,” p. 44. 
§ M. B. Waite, op. cit., p. 73: It may be pointed out that this author includes under the term 
**self-pollination ” transference to the flower pollinated of pollen from a flower of a tree of identical 
horticultural variety growing under similar conditions to that to which it belongs. When different 
horticultural varieties, or identical ones growing under different conditions, are concerned he 
employs the term ‘‘cross-pollination.” The present writer herein adopts the same connotation for 
the terms mentioned. $4.2 
|| Cf. Focke ; ‘‘ Die Pflanzen Mischlinge,” p. 447, 
