30O THE LIFE OF PHILIP HENRY GOSSE. 



" intelligible. How insects act with your Stanhopea I 

 "will not pretend to conjecture. In many cases I believe 

 "the acutest man could not conjecture without seeing the 

 " insect at work. I could name common English plants 

 " in this predicament. But the musk orchis is a case in 

 "point. Since publishing, my son and myself have 

 " watched the plant and seen the pollinia removed, and 

 "where do you think they invariably adhere in dozens 

 "of specimens? — always to the joint of the femur with 

 "the trochanter of the first pair of legs, and nowhere 

 "else. When one sees such adaptation as this, it would 

 "be helpless to conjecture on the Stanhopea till we 

 " know what insect visits it. I have fully proved that 

 "my strong suspicion was correct that with many of our 

 " English orchids no nectar is excreted, but that insects 

 "penetrate the tissues for it. So I expect it must be 

 " with many foreign species. I forgot to say that if you 

 " find that you cannot fertilize any of your exotics, take 

 " pollen from some allied form, and it is quite probable 

 " that will succeed. Will you have the kindness to look 

 " occasionally at your bee ophrys near Torquay, and 

 " see whether pollinia are ever removed. It is my 

 " greatest puzzle. Please read what I have said on it, 

 " and on O. arachnites. I have since proved that the 

 " account of the latter is correct. I wish I could have 

 " given you better information. 



" My dear sir, 



" Yours sincerely, 



"Charles Darwin. 

 "P.S. — If the flowers of the Stanhopea are not too 

 "old, remove pollen masses from their pedicels, and 

 " stick them with a little liquid pure gum to the stigmatic 

 " cavity. After the case of the Acropera, no one can 

 " dare positively say that they would not act." 



