447 



P.S. — The paper now sent has been hitherto kept back, in the hope 

 that I should ere this have had an opportunity of reading the work 

 referred to by Mr Watson. My namesake's queries (Phytol. ii. 377) 

 addressed to him on the subject of hybrids, induces me to submit what 

 I have written to the readers of the ' Phytologist.' My own impres- 

 sion is, that true hybrids are not capable of reproducing their kind. 

 Professor Henslow has stated that " Koelreuter ascertained that all the 

 plants raised between Digitalis purpurea and D. Thapsi, by fertilizing 

 the ovules of either by the pollen of the other, were constantly proli- 

 fic ; but then he also ascertained that D. Thapsi itself, when cultiva- 

 ted by him, after five generations assumed all the characters of pur- 

 pm'ea. He consequently rightly inferred that D. Thapsi was to be 

 considered no otherwise than as a Spanish variety of the more com- 

 mon form of the species." If other reported examples of fertile 

 hybrids were as rigorously scrutinized, I believe that the same result 

 would be obtained. Meanwhile it may be safely assumed, in reply 

 to Mr. E. S. Wilson's queries, that we shall never be able to deter- 

 mine what is or is not a hybrid, until we shall have first ascertained 

 what is really a species. In the present state of our knowledge, it ap- 

 pears to be the safest rule to pronounce a " fertile hybrid " a variety ; 

 and I confess I do not see the utility of such experiments as those in- 

 stituted by Mr. Watson and recommended by Mr. E. S. Wilson, unless 

 the permanency of a form under every variety of cultivation be assumed 

 as 'prima facie evidence of a species on the one hand; and on the 

 other, every deviation from the form of a parent stock, which is con- 

 tinued in the progeny of a variety, be considered conclusive evidence 

 that the variety is not a hybrid. What other test can be applied ? 



Januaiy 17, 1846. 



An Outline of the Flora of the Neighbourhood of Godahning, in the 

 County of Surrey ; with brief Notices of the Geological Features 

 of the District.* By J. D. Salmon, Esq. 



In bringing the Flora of Godalming and its neighbourhood before 

 the notice of botanists, it is necessary that the limits of the district 

 should be clearly defined, and that the geological features which pre- 

 sent themselves should be noticed: for the outline of the latter I have 

 availed myself principally of Dr. Mantell's Memoir in the ' History of 

 Surrey.' 



* Read before the Botanical Society of London, February 6, 1846. 



