-TKATJoN IIORTICOLE. 



/TOVEMENT OF WATER IN PLANTS. 



)vement of I That the removal of the cortical tissues does not impede 

 :ently been the rapid current in the stem which moves only: hroueh 

 i Academy, the wood portion of the fibro-vascular bundles. 



That a well-marked rapid flow of fluid will take place 

 f ascent of in the stem after the removal of the leaves. 



The fluid will rapidly flow downwards as well as upwards 

 ion, direct in the wood portion of the fibro-vascular bundles, as seen 

 current of in a branch in which lithium solution was applied at the top 



That pressure of mercury does not exert any very mark- 

 e, bypla- ed influence on the rapidity of the flow, in the one expe- 

 Ily retard I riment made with a pressure of 110-53 grammes of mercury. 



FALL AND RENEWAL OF THE LEAF. 



; the leaves of 

 le difficulty in 



mts in Enonymus japonicut 

 me few years ago Hoffmanr 

 ence could be artificially pro 

 that climate influences to a 

 period during which really 

 iage; but it appears far more 

 ogical peculiarities not alto- 

 s, as we find evergreen and 

 the same regions and under 



for examp 

 us Conifer* 



tivated Peach trees of the oases , in which it may not be 

 constant. Moreover, the Peach tree shows the same tendency 



wry curious plu-noin. -i inasmuch ils the ultimate branch- 

 lets are deciduous. The observations chronicled by Dr. 

 Ascherson agree almost entirely with our own experience. 

 On his outward journey he traversed 25° of latitude in less 

 than a month, which gave him an excellent opportunity for 

 stmluim- the condition of the same species under very 

 diverse climates. Thus, for instance, in the plains of Lom- 

 har.ly many deciduous trees, and especially Morus alba, were 

 still partially covered with foliage on the 19th of November, 

 iauu S ,on 8 previously shed their leaves 

 i" <-. rm.iny. h. a similar manner, the Fig trees in Lower 

 I ir>lit ;i Y lat.Muav partially clothed w ith foliage at the 



still in full leaf, nhil 

 they were quite hare i 

 11th of December, the 



leaf. Hence, one might 



t already, on the 24th of November, 



* the Apulian Plain (41° N.). On the 



Pomegranate trees in the gardens of 



f »and on New Year's Day, 1874, the 



• i were still in their prime of green 



^ li 'y imagine that on approaching 



nearer the equator the 



e same species would exhibit no in- 



terval between the fall 



thus, to all intents and 



and the renewal of the foliage, and 



•urposes . hecome evergreen. But this 



in mild seasons with us. In the oases, at the beginning of 

 March, when the trees began to blossom and make new 

 growth, the old leaves were still fresh and capable of assimi- 

 lation. All other deciduous trees and shrubs cultivated in the 

 gardens of Kasr Dghakel (25° 45' N. lat.), including the 

 Grape Vine, Apricot, Apple, Pomegranate, Plum, Fig, 

 Mulberry and Willow (Salix safsaf), had lost their foliage on 

 the arrival of Dr. Ascherson, or became leafless before the 

 end of January. It should be mentioned that the fall of the 

 | leaf in this region does not proceed with the same regularity 

 as at home, for it is not unusual to see quite naked and fully 

 clothed trees of the same species standing side by side. Again, 

 I the presence of abundance of moisture has the effect of enabl- 

 ing the trees to carry their old foliage longer, and put forth 

 their new earlier, than trees growing in drier situations. And 

 some of the Willows growing by water were quite evergreen; 

 that is , after the manner of the Peach trees mentioned above, 

 change | But the Apricot, one of the most- abundant trees, rarely 

 retained even a few scattered old leaves on the appearance 

 of the flowers. The same was observed of the Grape Vine, 

 Fig, and Mulberry. By Feb. 20 the Apricot trees were in full 

 blossom, and by March 10 in full foliage, so that there was 

 only an interval of four or five weeks between the fall of the 

 old foliage and complete development of the new. The Apple 

 and Plum behaved in ,-, similar manner, the Pomegranate 

 was a little later, the Fig next in order, and finally the Mul- 

 berry ; whilst the same things , in the reverse sense , lost their 

 leaves first. From the preceding notes it seems that the fall 

 and renewal of the leaf is an essential constitutional peculia- 

 rity, which is modified by climatic conditions, but not entirely 

 subject to them. A more striking illustration of this fact 

 may be found in exotic deciduous trees planted in Egypt. 

 Dr. Ascherson noted more particularly the summer fall of 

 the leaves of Poinsettia pulcle %, a South American 

 shrub, and AlUzzia lebbek, a native of the East Indies. The 

 former is in the full splendour of its inflorescence in Decem- 

 ber, and quite leafless in April , remaining so, it is said , until 

 the autumn. The Albizzia is extensively planted as an avenue 

 tree. It sheds its foliage in April , but soon renews it. Both of 

 these plants lose their leaves i 



„ native countries during 

 toe dry, and renew them with the opening of the rainy season. 

 (Extracted from « Nature . Dec. 17. 1874.) 



