Anatomie. — Biologie. 499- 



root and stem, in the latter they occur as small irregulär areas 

 in the pith, the cortex and also betvveen the vascular zones. 

 The pinnae of the leaf are forked in various ways. The cells 

 of the spongy mesophyll lying between the veins are only in 

 contact by comparatively small areas which are pitted and 

 lignified, the author compares this tissue with the „accessory 

 transfusion tissue" of the leaves of Cycas. 



D. J. Gwynne-Vaughan. 



FORBES, A. C, On the Regeneration and Formation of 

 Woods from Seed naturally or artificially sown. 

 (Trans. Engl. Arboricult. Soc. Vol. V. Part II. p. 239 

 —270.) 



The Introduction is devoted to a discussion of 1. the com- 

 parative advantages of Sowing and Planting, 2. the species 

 adapted for sowing in situ (natural regeneration) ; the oak, 

 beech, ash and Scots Fir are said to be best for this. 



In the first section on Natural Regeneration the conditions 

 necessary therefore are described; these are: 1. presence of 

 seed-bearing trees; 2. Cleanliness and Porosity of superficial 

 soil; 3. Absence of large quantities of raw humus; 4. necessary 

 covering of the seed by soil; 5. protection of seedlings from 

 ground game and other destructive vermin; 6. timely removal of 

 the old crop of seed-bearing trees. 



The subsequent treatment of a regenerated area consists in 

 the filling up of blanks and thin places by thinning out the 

 thick patches. In the case of oak and beech it is best to fill 

 up with larch, ash or others which can be taken out and 

 utilised. 



Natural regeneration is not much resorted to in this country 

 owing to the general presence of rabbits. Ash is the most 

 common tree met with as resulting from the process owing to 

 its producing great crops of winged seeds. The natural 

 regeneration of oak is rare because the acorns are devoured 

 by pigeons and pheasants. The best example of Beech-rege- 

 neration is seen on the Chiltern Hills. The greatest 

 success is obtained where all the badly-shaped and large-headed, 

 bushy trees are removed at each felling, for this results in tall, 

 small-crowned trees prevailing throughout the wood. 



As regard the natural regeneration of the Scots Fir (Piniis 

 sylvestris) it is stated that the failure of seedlings growing 

 under the shade of the parent is due to the fungoid layer 

 present in fallen Scots Fir needles, which is fatal to the radicle; 

 they require a heath-covered surface; they fall in grass or other 

 surface-growth. Details as to the preparation of the ground by 

 Clearing timber^ etc. is then given. The only other Conifer 

 suitable for natural regeneration is the Weymouth Pine 

 (P. Strobiis) ; it is much less sensitive to shade than the 

 Scots Fir. 



32* 



