about thirty days each year, was turned by the plant 
through the ages to such advantage to itself, because 
in seasons when the orchids are late in flowering or the 
females of Scola ciliata emerge from their burrows ear- 
lier than usual, the orchids are neglected and yield few 
if any seeds. And once the females of Scolia ciliata ap- 
pear, the males apparently lose interest in the orchid- 
flower and pseudocopulation is nolonger performed. Here 
indeed is a circumstance that is rather amazing. It forces 
us to assume gradual change and a series of slow modi- 
fications through a prodigiously long period of time be- 
fore the male insect and the orchid became biologically 
adjusted. Is it not true, that in contemplating the action 
of Natural Selection as Darwin propounded the doctrine, 
we think of modifying influences as being prolonged or 
in constant operation on the affected organism? And yet 
the direct stimuli associated with pseudocopulation that 
have affected the flowers in the case of Ophrys speculum, 
have been confined in their action to the brief flowering 
period, to the duration of anthesis, and under certain 
circumstances, in exceptional seasons, may operate for a 
very limited time. 
After studying the relationship between Ophrys spec- 
ulum and Scolia ciliata it would seem that the marvels of 
orchid-insect symbiosis had reached the furthermost limit 
of specialization, but such is not the case, because the 
observations of Monsieur Pouyanne in Algeria and of 
Colonel M. J. Godtery at Hyéres in the south of France, 
on other species of Ophrys, and the observations made by 
Mrs. Edith Coleman in Australia with regard to the pol- 
lination of Cryptostylis leptochila, through symbiotic re- 
lations with an ichneumonid wasp, throw the whole mat- 
ter of sexual relationship between orchids and insects 
into the realm of fascinating conjecture and stimulate the 
belief that in some departments of orchidology we are 
[8 ] 
