Longevity of Cut Flo^vera. 249 



did not shrivel and droop at all; apparently, if it had not l>een 

 for other causes, they would have kept indefinitely, but in every 

 case, after from ten to fourteen days, the specimens would Ixicome 

 discoloured. Ihis discolouring would commence with the part of 

 the stalk actually immersed in lead nitrate, and gradually spread 

 until it affected the whole stalk, leaves, and, lastly flowers, so that 

 in no case could the flowers really lie called fresh for mc.rc than 

 fourteen days. 



In many cases the articulation between the pedicels of the capi- 

 tula and the stems become loosened, with the consequence that the 

 capitula fall off very easily, although remaining quite fresh. 



It will be seen tliat the exact effect of the lead nitrate varies with 

 the different species; for example, no experiments with Acacia 

 armata succeeded, and the effect on other markedly xerophytic 

 species, such as juniperiua and verticillata, was very slight. A 

 good deal of variation is noticeable in the effect of the lead nitrate 

 on different specimens of the same variety. In some experiments 

 the control and the specimens in lead nitrate have lasted for an 

 ecjually short period, whereas another experiment with the same 

 variety will give a good, result. In all cases where rapid withering 

 has taken j^lace detailed sectioning and examination of the stem 

 shows blocking. There is presumably some undetermined factor 

 which controls the extent of the exudation, and the effect which 

 immersion of the stem in lead nitrate will have on this. It is pos- 

 sible that the length of time intervening between the time that 

 the blossom is picked, and the time that it is placed in the solution 

 will have a considerable influence on its longevity. Accurate ex- 

 periments to determine this point have not yet been carried out; 

 but it Avas noticed that in any case w^here the l)lossom had l)een 

 kept for some time, and had begun to wither, the lead nitrate did 

 not exert a reviving effect, but the specimen would remain in a 

 drooping condition for a long time, whereas the control would com- 

 pletely witlier. That is, the lead nitrate does not dissolve block- 

 ing already formed, but prevents any furtlier exudation taking 

 place. Another possible factor influencing the amount of bhx-k- 

 ing shown in the stem miirht be the age of the wood forming the 

 vessels at the cut part. Ihis point was also undetermined. 



Tables to show the influence of raryinrj stretujths of had and 

 silver salts on the lon(je\vity of the blossoms of varying siKcies of 

 Acacias. 



[The number of days quoted under each column indicates the 

 number of days that the specimens remain fresh.] 



