86 Ml' Willis and Mr Burkill, Observations on [May 15, 



no trace, but in all the 75 cases recorded the ivy was found simply 

 in the tops. 



Sambucus. Extremely common everywhere. 



Galium Aparine. This plant heads the list of records. It is 

 extremely common in the whole district. The burr fruit is well 

 adapted for clinging to animals and probably birds carry it largely 

 to the trees, adhering to their feathers ; the numbers in Class I. 

 show how largely they visit the trees. Galium is also used for 

 nest building, as will be seen below. 



Urtica. Common everywhere, but mostly in districts B and D. 



Dactylis. Most common in the fen districts. 



Comparing our list with that given by Loew for the willows he 

 examined, it appears that of his 31 species, 11 are not present in 

 our list, and Bolle* gives 8 more that do not occur in ours. 



A comparison with the flora of the churches of Poitiers*f* shows 

 that our flora contains far more bird distributed species in propor- 

 tion to the total, viz. 22 species out of 80, as contrasted with 3 in 

 76. This is what would be expected in view of the fact that birds 

 so largely visit the willow trees. Of Richard's 76 species, only 14 

 occur in our list. 



Other floras of similar character J exist, but need not be specially 

 discussed here. 



Birds' nests being common in willow tops, it seemed to us that 

 the plants used in building might become established in large num- 

 bers by this means, and we have therefore made an analysis, so far 

 as possible, of a few nests taken at random. Among the materials 

 of the nests were found the following : 



(1) Two thrushes' nests from Dernford Fen (section E). 

 Anthriscus sylvestris, stems. 



Galium Aparine, many stems, 13 fruits, and a living 



seedling, rooted. 

 Urtica dioica, many stems. 



Poa annua and P. pratensis, stems, leaves and panicles. 

 Brom,us sterilis, panicles. 

 Glyceria aquatica, stems and leaves. 

 Agropyrum repens, „ „ 



(2) One thrush's nest from Swafl"ham Lode (H). 

 Senecio aquaticus, stem, 



Lamium purpureum, living plant, rooted in the nest. 

 Dactylis glomerata, entire plant. 



* "Naehtrag zur Florula der Kopfweiden," Verhandl. d. hot. Vereim d. Prov. 

 Brandenburg, xxxiii., 1892, p. 72. 



t Eiehard, "Plorule des clochers et des toitures des eglises de Poitiers." Paris, 

 1888. 



J See list in Kichard, loc. cit. , p. 48. 



