1880.] Destruction of Obnoxious Insects by Fungoid Growths. 575 
that the numbers joined might theoretically come at once. Our 
theory seems, therefore, to be proved correct as far as it goes, 
and sufficiently so to justify another inference, viz: that when the 
longer petal is on the right side, the parts of the flower are 
arranged in a right handed spiral; and when it is on the left side 
the spiral is left handed; and, therefore, that in the inflorescence 
Successive flowers on the same branch have spirals in opposite 
directions. 
But why in opposite directions? And why, too, should 
stamens imitate leaves in the order of their development? Is ita 
kind of structural memory, or material instinct? The habits of 
‘growth impressed by one set of circumstances where they are 
advantageous, showing themselves where they clearly have not 
the same advantage, if any at all? 
Where shall we stop? But before leaving the case, let us not 
overlook the fact that in the later explanations, we have been 
giving reasons of a very different order from those in the earlier. 
We then thought it sufficient to show the advantage in a par- 
ticular arrangement, now we are almost satisfied when we see 
how certain forces, more or less familiar, may have produced the 
facts under consideration.. Neither kind of solution is complete. 
Let us not be deceived by the ambiguity of the word wy. It 
should still be asked %ow the structures so admirably adapted to 
cross-fertilization have been produced, and we may still ask why 
the facts concerning the stamens exist. Whether they are 
advantageous and serve a purpose in the economy of na‘ure, or 
Whether they are, as it were, rudimentary phenomena, the inci- 
dental effects of laws which have been established for some really 
important purpose. Such questions we have now no time to 
ollow. 
207 
DESTRUCTION OF OBNOXIOUS INSECTS BY MEANS 
OF FUNGOID GROWTHS. 
BY PROF, A. N. PRENTISS. 
~NTOMOLOGISTS have been, for a long time, endeavoring 
to discover some available means for checking the ravages of 
obnoxious insects, and of late the possibility of employing fun- 
goid growths for this purpose has been receiving considerable 
attention. The most important paper which has. appeared upon 
