att 
however, of how profoundly modified in this particular case the plant 
and the insect have become in their mutual adaptation, I may state 
that the perfect Smyrna fig, the most 
esteemed of the edible varieties. can 
be produced only by the intervention 
of the Blastophaga psenes, and that 
Dr. D. D. Cunningham has recently 
shown, in the Annals of the Royal Bo- 
tanical Gardens of Calcutta (Vol. 1 
Fig. 74.—PRODOXUS COLORADENSIS: 4, leit Appendix I, 1859), by repeated exam- 
front wing. hair-line underneath showing jnations of the fruit of Ficus roz- 
ee ee ee  purghi, that pollination, sake mle 
nary meaning of the term, is, in that 
particular case, out of the question, and that the development of the 
seed in this species is exclusively due to the stimulation of the tissues 
caused by the puncturing of the Blas- 
tophagas: in other words, that these 
insects actually represent the male ele- 
ment in the fertilization. This cer- 
tainly is the most extraordinary phe- 
nomenon in the history of fertilization, 
and it confirmed—and Dr. Cunningham 
has been most careful and circumspect ry. 5._Propoxts ReTICULATUS: Female 
in his work—it will give a more strik- *#th wings expanded—hairline showing 
ing instance than any we have hitherto gies ce 
obtained of the mutual interdependence which plants and insects may 
attain and the surprising manner in which they may modify each other. 
GENERALIZATIONS. 
The peculiarities which I have endeavored to present to you are full 
of suggestion, particularly for those who are in the habit of looking 
beyond the mere facts of observation in endeavors to find some rational 
explanation of them: who, in other words, see in everything they observe 
significances and harmonies not generally understood. The facts indi- 
cate clearly, it seems to me, how the peculiar structures of the female 
Pronuba have been evolved by gradual adaptation to the particular 
functions which we now find her performing. With the growing adapta- 
tion to Pronuba’s help, the Yucca flower has lost. to a great extent, the 
activity of its septal glands: yet coincident with this loss we find an 
increase in the secreting power of the stigma. This increase of the 
stigmatic fluid doubtless had much to do originally with attracting the 
moth thereto, while the pollenizing instinct doubtless became more 
and more fixed in proportion as the insect lost the power or desire of 
feeding. . : 
With the mind’s eye I can look back into the past and picture the 
gradual steps by which the Prodoxids to which I have alluded have 
