^Sg THIRD REPORT — 1833. 



Association, Catalogues of County or other local Floras, with 

 indications of those species which have been recently intro- 

 duced, of those which are rare or very local, and of those which 

 thrive, or which have become, or are becoming extinct ; with 

 such remarks as may be useful towards determinhig the con- 

 nexion which there may be between the habitats of particular 

 plants, and the nature of the soil and the strata upon which they 

 grow ; with statements of the mean winter and summer tempe- 

 rature of the air and the water, at the highest as well as the 

 lowest elevation at which species occur ; the hygrometrical 

 condition of the air, and any other information of an historical, 

 oeconomical, and philosophical nature. 



*2. That Professor Daubeny be requested to institute an ex- 

 tended inquiry into the exact nature of the secretions by the 

 roots of the principal cultivated plants and weeds of agriculture ; 

 and that the attention of Botanists and Chemists be invited to 

 the degree in which such secretions are poisonous to the plants 

 that yield them, or to others ; and to the most ready method of 

 decomposing these secretions by manure or other means. 



* A Committee was formed to conduct a series of experi- 

 ments on the growth of plants from seeds, and to preserve the 

 results of their experiments, in order to establish the identity 

 or confirm the specific distinctions of certain allied plants, and 

 to communicate the results obtained, from year to year, at the 

 Meetings of the Association. 



Mr. Don, Librarian to the Linnaean Society, has undertaken 

 to be the channel of correspondence on this subject. 



Desiderata noticed in Professor Lindleys Report. 



1. An accurate account of the manner in which the woody 

 part of plants is formed. " Perhaps there is no mode of pro- 

 ceeding to elucidate this point, which would be more likely to 

 lead to positive results, than a very careful anatomical examina- 

 tion of the progressive development of the mangel wurzel, be- 

 ginning with the dormant embryo, and ending with the perfectly 

 formed plant." 



2. An investigation of the comparative anatomy of flowerless 

 plants, with a view to discover in them the analogy and origin 

 of their organic structure. 



3. The cause of the various colours of plants. 



4. The nature of the feecal excretions of cultivated plants, 

 and of common weeds ; the degree in which those excretions 

 are poisonous to the plants that yield them or to others ; the 

 most ready means of decomposing such excretions by manures 

 or other means. 



