Jan. 1892.] THE BOTANICAL SOCIETY OF EDINBURGH. 239 



Every single species I studied, except one, was visited by- 

 insects, and, in the vast majority, the visits were numerous 

 enough to fertilise every pod. The single exception 

 was that of Senehiera Coronopus, which I could only 

 watch for about three hours on a hopelessly wet and windy 

 day. 



The following Table shows the state of the evidence at a 

 glance. Insect-visits are, however, very much more numerous 

 than one would suppose from it. I could not give an 

 exhaustive list of any single species ; such a list, to be 

 thoroughly complete, would take about six weeks of careful 

 work on every single form. Moreover, I could not get 

 names for a very large number of insects which I did not 

 catch, and which are therefore not noticed. 



The first and second columns in the Table give the 

 number of species of insects observed by myself ^ and 

 Miiller t respectively ; the third column is the sum of the 

 first and second. The fourth column is an attempt to 

 estimate the frequency of insect-visits. In calculating this, 

 I tried to take into account the average life of each flower 

 or number of days during which it is open to insect-visits, and 

 then, by calculating the number of individual insect-visits^ 

 seen by me in a specified time, and making allowance for bad 

 weather, to estimate how many individual insect- visits occur 

 within a flowering period. The result is, of course, in a 

 measure, guesswork, or a matter of opinion ; but I tried to give 

 every possible doubt to the self-fertilising side, and I think I 

 have very much understated the probability of insect- visits. 

 In further explanation of the Table, I understand that the 

 number " 4 " means that every individual flower is visited 

 more than once by insects during its blossoming period ; 

 the number " 3 " means that every individual flower is 

 probably visited at least once ; the number " 2 " means that 

 half the flowers of the species are visited once by insects ; 

 the number " 1 " means that not half the flowers are so 

 visited ; and the number " " would mean that no insects 

 were noted on the plant, but, as will be seen, it does not 

 occur in the Table at all. 



* The three species on Teesdalia were caught by Jliss Ethel Tayloi', fruin 

 whom I received them, 

 t Miiller, Fertilisation of Flowers. 



