10G REPORT — 1877. 



On tlie Fossil Flora of tlie Arctic Regions ; an Extract from a Letter from 

 Prof. Heer to Sir Joseph Hooker, K.C.S.I., F.B.S. Communicated by the 

 Eov. W. S. Symonds. 



This was an extract from a letter from Professor Heer to Sir Joseph Hooker, and 

 gave data relative to the flora found in extremely high latitudes. 



On the recent occurrence of Lavatera sylvestris, Brot., in the Scilly Islands. 

 By Henry Tkimen, MM., F.L.S. 



This Mallow was collected first in July 1873 by Mr. Curnow of Penzance, on tho 

 Island of St. Mary, and again in 1876. During the past summer it was found in 

 abundance in the islands of St. Agnes and Tresco. 



The exotic range of the species — Portugal, Madeira, Azores, Canaries, and Mo- 

 gador — shows it to belong to that small, but interesting type of distribution to 

 which the name " Atlantic " may be fitly applied. Of this type the western counties 

 of England already possess several examples, e. g. Arihrolobrium ebracteatum, 

 Erica vayans and E. ciliaris, Trifolium strictum, T. Bocconi, and T. Molinerii, 

 Hypericum bcsticum and H. linarifolium, Physospennum comubiense, liume.v ru- 

 pestris, and Lobelia arem. The term " Atlantic" was employed by Mr. H. C. Wat- 

 son to indicate those and other species also which are confined in a similar way to 

 the west of England. Many of these latter, however, do not in their exotic dis- 

 tribution exhibit the same strictly Atlantic distribution, but occur also in Central, 

 Southern, or even Eastern Europe. 



Lavatera sylvestris, though thus agreeing with the true Atlantic type in its 

 distribution, cannot, however, be considered native in Scilly (as was supposed by 

 its discoverer there) for the following reasons: — (1) It was not seen there in 1863 

 by Mi*. Townsend, a careful botanist, who published a list of the flora of the 

 group. (2) In the original station in St. Mary's it grows in company with Reseda 

 fruticidosu, and looks clearly an introduction, in the opinion of Mr. T. R. A. Briggs. 

 (3) It appears to have spread very rapidly, a characteristic of several Malvaceae, 

 e.g. Malva borecdis, Wallm., near Plymouth, and Lavatera cretica, L. (a close ally 

 of L. sylvestris), in several points of the coast of Western France. (4) A few spe- 

 cimens have occurred near Penzance, on the mainland of Cornwall, under circum- 

 stances clearly showing it to be a mere casual introduction. 



On Structural Characters in relation to Habitat in Plants. 

 By A. S. Wilson, M.A., B.Sc. 



Anatomy and Physiology. 



[For Prof. Macalister's Address, see page 87.] 



The Structure and Development of the Vertebrate Skull. 

 By G. T. Bettany, M.A., B.Sc, 



This paper gives an account of conclusions to be published in an immediately 

 forthcoming work on the ' Morphology of the Skull,' by Prof. W. K. Parker, 

 F.R.S., and G. T. Bettany. The trabecule are believed to be structures of the 

 same order as the parachordal and basilar cartilages of the skull, and to be similar 

 to the lower parts and base of neural arches in the vertebral column. The skull 

 becomes a more or less continuous neural tube of cartilage, with new perforations 

 at intervals, and a series of sense-capsules embedded in it laterally. The only 

 part of the craniuni answering to the main part of the vertebral centra is a slender 

 tube of tissue surrounding the notochord, which becomes separately ossified in some 



