FROM AX OLD STANDPOINT. 



195 



theory presents iis with a good working hypothesis, at least 

 for the age of the Angiospernis which hegan in the Upper 

 Cretaceous epoch. Beyond yawns a gap between the present 

 and the ancient order" of vegetation. It has not been bridged 

 over, and seems nnl'athomable. "Whence came the Angio- 

 sperms?" is the question that students of past floras are ever 

 putting to themselves. Did tliey come across the gap ? To 

 this at present there is no reply. "We are profoundly 

 ignorant," says Mr. Seward, "of the means by which nature 

 produced this new creation" (Brit. Assoc. Address, 1903). 



Discussion. 



The Secretary (Professor Hull, F.R.S.), in moving a vote of 

 thanks to Dr. Guppy — who was unable to be present in consequence 

 of being detained in Jamaica —considered the paper as one of unusual 

 interest from the point of view of a naturalist. It gave us in a 

 condensed form the results of observations carried out in various 

 countries, and treated at large in the author's most recent work, 

 Ohcrmtions of a XafiiraUst in the Pacific, vol. ii,^ dealing with the 

 subject of "Plant-Dispersal." This is a highly complicated subject, 

 involving as it does not only the agencies by which dispersal of the 

 seeds and spores of plants is effected, but the changes in the dis- 

 tribution of land and sea, owing to which lands once connected have 

 become separated and isolated, by which climates have been altered, 

 and by which differentiation of genera and species has been advanced. 

 I think it must be admitted that Dr. Guppy has made out a very 

 strong case in favour of his theory that an original wide-spread 

 parent-form of a plant has, owing to physical changes, become 

 ths united into separated areas, in which differentiation has progressed, 

 resulting in the production of fresh genera and species ; nor is it 

 improbable that this process may in some cases have resulted in the 

 production of identical genera and species, rising from independent 

 originals or tribes. How otherwise can it be explained that 13 per 

 cent, of the genera and 41 per cent, of the species belonging to 

 24: famiUes are common to the Old and New Worlds which have 



Macmilhm and Co., 190G. The vohime has been presented by the 

 Secretary to the Library of the Institute. 



