390 BOTANY [CHAP. XI 



Letter 710 of rendering the seeds dormant after the manner of the ants," and that 

 indeed " its influence is always injurious to the seeds, even when present 

 only in excessively minute quantities." Though unable to explain the 

 method employed, he was convinced " that the non-germination of the 

 seeds is due to some direct influence voluntarily exercised by the ants, 

 and not merely to the conditions found in the nest" (p. 172). See Vol. I., 

 Letter 251. 



Down, Feb. 2ist [1873]. 



You have given me exactly the information which I 

 wanted. 



Geniuses jump. I have just procured formic acid to try 

 whether its vapour or minute drops will delay germination of 

 fresh seeds ; trying others at same time for comparison. But 

 I shall not be able to try them till middle of April, as my 

 despotic wife insists on taking a house in London for a month 

 from the middle of March. 



I am glad to hear of tbe Primer j 1 it is not at all, I think, 

 a folly. Do you know Asa Gray's child book on the functions 

 of plants, or some such title ? It is very good in giving an 

 interest to the subject. 



By the way, can you lend me the January number of the 

 London Journal of Botany for an article on insect-agency in 

 fertilisation ? 



Letter 711 To J. Trahenie Moggridge. 



Down, Aug. 27th, 1873. 



I thank you for your very interesting letter, and I honour 

 you for your laborious and careful experiments. No one 

 knows till he tries how many unexpected obstacles arise in 

 subjecting plants to experiments. 



I can think of no suggestions to make ; but I may just 

 mention that I had intended to try the effects of touching the 

 dampened seeds with the minutest drop of formic acid at the 

 end of a sharp glass rod, so as to imitate the possible action 

 of the sting of the ant. I heartily hope that you may be 

 rewarded by coming to some definite result ; but I fail five 

 times out of six in my own experiments. I have lately been 

 trying some with poor success, and suppose that I have 

 done too much, for I have been completely knocked up for 

 some days. 



1 Botany (Macmillan's Science Primers). 



