NOTES ON RECENT RESEAECH. 



52J 



the formation of resin ; the idioblasts scattered in the ground- tissu^ 

 the various interceUular resin-holding canals and cells, and the epidermal 

 hairs, glands, &c., being very fully treated. The resin is.regarded.^^^ 

 final product of metabolism. The taste or smell is of importance as 

 either attracting insects or preventing injurious insects or animals from 

 touching the plant. In many buds resinous bodies assist in keeping 

 down the transpiration of the younger leaves. 



The chief results were as follows : — Resin-secreting glands only were 

 discovered in the PolypodiacecE. The internal glands were unicellular 

 trichomes, except the schizogenous resin-ducts in Aspidium athamanti- 

 cum. The epidermal glands were sometimes multicellular, but with a 

 single cell at the tip. Internal glands were found in a great number of 

 cases, Aspidiu7n filix mas, A. sjnnidosicm, and nine other species. They 

 occurred in the rhizomes, bases of petioles, petioles and leaf- segments. 

 These internal gland-hairs possess a cuticle ; the resin is secreted between 

 this and the inner wall. In the gland-hairs of Gymnogranime species 

 resin is found on the outer surface. 



Epidermal resin glands were found either on the epidermis of the 

 petiole, on the leaf-segments, on the scales, on the indusia, or on the 

 sporangia stalks, in a number of species of Aspidium, Gyinnogramme, 

 Blecliimm, &c. The AspleniacecB and AcrostichacecB have but few glands, 

 and the Davalliece appear to be without excretory organs of this kind. 



The resin appears to arise in most cases by a change of the lamella 

 of the membrane, though in some cases by an excretion of the cell-mem- 

 brane. It is always produced by the cell-wall. 



The author also describes resin secretion in Senecio viscostts, Ononis 

 spinosa, Pelargonium zonale, and Erodium cicutarium with a view to 

 showing that in these cases also (not as suggested by Behrens) the resin 

 is formed from the cell- wall. — G. F. S.-E. 



Fruit of ScKOPHULARIACEiE. 



Scpophulariacese, The Anatomy of the Fruit of. By A. 



Weberbaur {Beih. Bot. Cent. bd. x. ht. 7, pp. 39-1-457, Table I).— The 

 writer describes the exact character of the dehiscence of the capsules 

 and anatomical details for about 140 genera of this order. In by far 

 the most cases, one or several layers of woody cells are arrcinged on the 

 inner side of the fruit-wall. Thin-walled cells occur on the outside, the 

 woody and thickened layers being either the innermost layer or the next 

 to it. A description is given of the types upon which those fruits which 

 show imbibition movements are constructed. The imbibition movements 

 depend upon the contractions and expansions of the radial walls, whilst 

 similar contractions and expansions in the tangential direction are unusual. 

 The capsules generally open when dried and close if moistened, generally 

 by a curving outwards, though in a few cases by an inward curvature. In 

 some cases, however, the capsules open and let the seeds escape when 

 they are moistened. This occurs in Aptosimiim, some Veronica sp., 

 Monttea, Lafuentea, Striga, &c. Most of these are desert plants. 

 Melampyrum fruits open through the growtli of the seeds which fall 

 close to the plant. Ants carry the seeds of this plant. In Verhascuin the 

 seeds are contained in the capsules all winter, and probably only escape 



