9 



On the Investigation op Floral Development. 

 By Marcus M. Hartog, M.A., B.Sc, F.L.S. 



(Read December 28th, 1877.) 



(Abstract.) 



The author commenced with some expression of regret that a 

 subject of such importance should have received so little attention 

 in this country, that the only reference to it in any English 

 text-book was in the latest editions of " Lindley's Introduc- 

 tion to Botany." He recommended its study as of great utility 

 and interest, and proceeded to give some useful hints as to 

 the best methods of procedure. The microscope to be used 

 for the purpose should give clear detail, with powers ranging from 

 10 to 60 diameters, and must possess freedom from colour ; the 

 simple form was better than the compound, as it gave plenty of 

 working distance and side light, with clearer perception of 

 relief. The pattern specially recommended was one by 

 Arthur Chevalier, which had a heavy, steady stand, and a large 

 stage, and admitted of the magnifier being moved in every 

 direction ; whilst the doublets supplied by that maker an- 

 swered the purpose admirably, giving a very large and flat field 

 of view. The needles most suitable were lance-shaped, suffi- 

 ciently broad at the base, finely tapering towards the point, 

 and sharpened on both edges ; with these, practice only would 

 be needed to carry on the finest dissections. Payer and 

 others recommended early morning light as the best to work 

 with, it being grey, as distinguished from the more coloured 

 rays of evening, and illuminating the object under examination 

 in a horizontal direction, which was very advantageous. The 

 process of working consisted in taking off the parts of the flower 

 one by one to see what lay underneath, and in illustration of 

 the process, the author described the manner in which the 

 flower of the Foxglove should be dissected, in order to trace back its 

 origin to the first appearance as a hemispherical elevation on the 



