676 



THE GARDENERS' CHRONICLE. 



_ favourable ear to any proposal for opening another 

 road into the Strand through Charing Cross, and for 

 thus connecting Belgravia with the city. 



With regard to the proposed bridge itself, small 

 as the scale necessarily is on which we are obliged 

 to represent it, there can scarcely be two opinions as 

 to the charming effect which it will produce when 

 executed. It crosses the water upon three beautiful 

 cast-iron bronze-coloured arches, gracefully deco- 

 rated with statuary, and enriched lamp- posts.* At 

 either end it is connected with the Mall by passing 

 over a colonnade in harmony with the bridge and 

 affording ample communication between the two 

 sides of the Park, exactly where the present walk 

 passes by the margin of the water. On the one 

 hand the Horse Guards will be seen in the distance 

 beneath the arches ; on the other will be had a view 

 of Buckingham Palace. The whole will be a 

 structure worthy of the good taste and architectural 

 reputation of Mr. Pennithorne. 



Nor will the roadway take anything appreciable 

 from the present park, for it is carried through the 

 masses of bushes, which now extend nearly from 

 the Mall to the water, and which will hereafter to 

 a great extent mask the roadway till it reaches the 

 colonnades. We may also add that the direction of 

 the road is such that only one tree of the least im- 

 portance will have to be removed. 



Ifwehaveat all succeeded in making the pro- 

 posed measure intelligible, we confidently believe 

 that the good sense of the public will put an end to 

 all further cavilling on the subject, and that the 

 sanction of S.r Benjamin Hall's plan will be one of 

 the earliest as well as most popular acts of the next 

 session of Parliament. 



to 



our 



We are continually called upon to give 

 opinion on some particular disease, and to suggest a 

 remedy, without a particle of information as to pre- 

 vious treatment, or any intimation of the conditions 

 under which the diseased plants have grown. Such 

 is the case at the present moment with specimens of 

 Gladioli which formed part of a large bed, consist- 

 ing of various varieties, all of which seem to have 

 been affected almost indiscriminately by some 

 disease which has caused a total failure. The 

 tubers have either rotted off suddenly at the base 

 when the stem and leaves were apparently healthy, 

 or the whole plant has gradually withered. In 

 either case it should seem that the affection is pre- 

 cisely the same ; that of the organs above the roots 

 it is the base of the tuber from whence the roots 

 are given off which is affected ; and that the leaves, 

 stem, &c, above the tuber perish only in conse- 

 quence of the proper supply of nutriment being cut 

 off below, or the little which passes vitiated by 



decomposed matter. 



Now if the roots themselves are examined, their 



condition will be found such as to make it very 

 probable that the evil has commenced there, and 

 that the base, which consists principally of a com- 

 plicated mass of vascular tissue, has perished in 

 consequence of some malady affecting, in the first 

 place, their extreme branchlets. The roots consist 

 of a conical stratum of irregular cells succeeded by 

 ligneous cells, and then by a large cylinder of vas- 

 cular tissue composed of scalariform reticulated and 

 spiral vessels threaded by large ducts. The first 

 indication of disease consists in a discoloration of 

 som« of the vessels, especially those which have a 

 real spiral thread. Other vessels, however, are 

 affected, and after a time they are either completely 

 clogged up by brown matter, or they contain scat- 

 tered brown granules very distinct, tolerably regular 

 in outline, and larger than those which attracted 

 so much attention in the first speculations on the 

 origin of the Potato murrain. If a root is cut 

 through in this state a black spot appears in the 

 centre, confined to the vascular portion. Matters, 

 however, do not remain in this condition. Fungous 

 threads soon appear in the cavities of the vessels 

 running up the walls or passing from tube to tube, 

 the consequence of which is that the whole portion 

 affected by them decays, and the root is often found 

 to have 





its 



lost the whole or the greater part of 

 vascular 



apparatus by mere decomposition, 

 whether induced immediately by disease or by the 

 action of the fungus, so as to present a hollow 

 cylinder. Under such conditions it is easy to under- 

 stand that the base of the tuber could not long 

 remain healthy. / 



Now without an opportunity of inspecting the 

 locality it is perhaps ra*hi to suggest a cause, but as 

 vegetation appears to have gone on well up to a 

 certain point, though it has evidently been checked 

 after a time from the small size of the new tubers, 

 and there is no reason to believe that the disease 

 is due to fungous matter, while the upper portions 

 should seem to have perished simply from the 



— : ;_________ 



* These are not represented on the accompanying elevation. 

 They are tastefully connected with the statues. 



[Oct. 



i. 



U 



• 



O 



I 



> 



I 





5 

 — u 





X 



■ 



, -~^l\ 



■*4 



o> 



7/ 





1 



Z 



o 







t 





6 



w 



-.' 





I KJ1 







■1*» 



I 









*, 





o 'x**! 



~ 



1-wt .- 





\ 







■y 



.* 







n 



i 





X- 



- J 





% 



.,- 



1 



e 



e 





induced decomposition and ultimately given rise 

 fungal mycelium. These Gladioli dive deeply i n f° 

 the earth for moisture, and if a proper supply 

 has failed below during the excessive drought of th 

 past summer, while the more superficial fibres hav 

 rapidly absorbed that which has been applied 

 frequently to the surface, it is very possible that an 

 unhealthy condition may have been induced, which 

 has ultimately affected the base of the tuber and 

 in consequence the vitality of the whole plant. We 

 are convinced that in many a case where the Melon 

 and Cucumber diseases are accused of being the 

 authors of failure, the prime cause of evil has been 

 slight superficial watering, while the deeper roots 

 have been seated in a dry and often a burning soil. la 

 many a case complete drought is less injurious than 

 a mere sprinkling, which, if repeated frequently 

 renders the plant only more impatient of drought 

 while the supply is quite insufficient for its wants. 

 It is very possible that in the case of the Gladioli 



we may be wrong, though we feel sure that the 

 cause has been external, whatever it may have been, 

 and that which we have mentioned is capable of 

 producing such an effect, and accords with our own 

 experience in similar cases ; but our remarks will 

 not be useless if they check the practice of frequent 

 but scanty watering. It is very true that Melons 

 will not bear much drenching, at least in our 

 climate, though the continental ^ practice is very 

 different from our own ; but it is equally certain 

 that they cannot thrive when the subsoil is void of 

 moisture, and a great bottom-heat is applied. If 

 the spongelets are once affected, or the smallez 

 fibres decay, there will always be danger of decom- 

 position in the larger roots, and this will generally 

 be aggravated by fungi, and according as the decom- 

 position assumes a moister or a drier form will be the 

 rapidity of the affection. 



In the case before us it may be added^ that the 

 mycelium is probably that of Cladosporium her- 

 barum, the most common of all fungi, and which is 

 breaking through the plant in every direc- 

 tion. M. J. B. 



abstraction of the proper supplies, we must look for 

 some external cause, and this may very possibly 

 have been some accidental drought, which has 

 affected the spongelets and thus in process of time 



VEGETABLE PATHOLOGY.— No. XCI. 

 372. Caries {Decay).— True canker may be compli- 

 cated by the presence of gum, resin, or watery fluid, 

 and its real na'ture in consequence masked or entirely 

 concealed. Every case, however, in which the more 

 firm or solid portions of a tree are subjected to ^com- 

 position is not due to canker. Funcfi or insects my 

 have in the first place led to mischief, aifd » decay ol 

 the older parts ensued. In the natural course of thing*, 

 however, where everything has been perfectly healthy, 

 the organism will not live for ever. As a new -layer a 

 bark and wood, and consequently a new set ;of buds 11 

 added every vear, life may be prolonged indefinitely 

 in the direction of the circumference, but the older 

 internal portions which have long since performed tneir 

 functions gradually lose their vitality and become sud- 

 ject to chemical decomposition even where no external 

 agents or accidents favour the process. They acquire 

 in consequence a darker hue, assume the characters ci 

 ulmates and humatee, and finally the central portions 

 become soft, lose their adhesion and form a friw 

 powdery mass. The decayed matter acts as a pu^ 

 factive ferment on the neighbouring tissues, and som - 

 times becomes moist from the absorption of sap , 

 the process goes on till some portion of the tree g ; 

 way in consequence of the wood becoming too in 

 brittle to support the weight of leaves and fruit, ^ 

 thus moisture is introduced from without or an e 

 formed for the decayed matter. The tree mj 

 becomes hollow, and in favourable circumstai^w ^ 

 outer portions are still renewed, and somet^ 9 ^ 

 ternal fissure is obliterated by the projection 0^ 

 new structures on either side, and matters pr ^ g 

 a new cycle of phenomena has run its course an , 

 to the same result. Decay is, however, seldom \ 

 ent simply on the natural course of decotnp <* 

 Even where there is no external injury tne 

 tissues are soon threaded with the mycelium 1 oil 

 sitic fungi, which aid materially in the decompc > 

 of the firmest structures. The fungus itself soon ^ 

 its appearance in various situations accord,n f ^ he oU t- 

 ferent specific circumstances, and the agency ^ 

 ward elements rapidly aggravates the evil. . ^fr 

 most complicated circumstances, however, it 1 s j ocin g 

 ing how many years a hollow trunk will resist p ^ ^ 

 every year as good and abundant fruit as 1 gg % 

 were perfectly sound. To take the *PP le JLireri* 

 familiar instance, whose wood does not in gen 



many forest 



do the 



,y art 



other 



attacked by the spawn of Polyporus b»*P> d "* ove t iJe 

 fungi. If the fungus makes its appearance « ^ , 

 only, decay may be confined to that side, a . ^ 

 series of years ihe wood pves way ; no» ^ thl9 

 produced, and the tree becomes hoJ»w > weatb < r , » 

 condition, with proper care to j^nde . tnt ^ |he 

 may continue fruitful for y«*f s. g» wev ' ^ tl , e 

 contrary, the fungus «ore generally appe ^ 

 base and the de**y proceeds upwards. , 



case, however, where it is desired »F iot » 

 tree either for use or ornament, the g r ^. 

 to remove the decayed matter as compel . 



