^VoL. VIII. No. 181. 



THE AGRICULTURAL NEWS. 



107 



FLOWER AND FRUIT STRUCTURE IN 



THE PA PAW. 



Among the ]iapers siiininniizL'r] iiithi' K.rp-r'i mcnt 

 ^Statiiiri Rii-iiril ol XdveinlH-r hisi'is diic whirh was 

 publisliPil in the Ballitiu nf tlic Torrctj BuUiiiiad 

 Glah (J><o. 3, I90S), and deals with a study that has 

 been made nt'thepapaw { Car Ira papa i/a) to determine 

 whether the <levelopment and t^trncture of the fruit 

 -might be coirelated with the stniciure of the Hower. 



In this study notes wcio takea in relation to a number 

 of tio\ver.s on the same tree. In this connexion it may be 

 mentioned that the papaw plant is )iornially dioecious, i.e., 

 male flowers only are produced on some tree.s, and female 

 Howers only on others ; in rare cases, however, perfect or 

 bise.\ual flmvers are produced on eitiier male or female trees. 



There was found to be a distinct correlation between the 

 formation and size of the fruit and flower characters. Where 

 the ovary was small and slender, with rays in the stigma 

 nearly aborted, the fruits grew eomparativelj' small, cylindri- 

 cal, almost solid, with exceedingly small seed cavity, contain- 

 ing few .seeds; while where the pistil was normal or nearly 

 so, the fruit grew large, Uiore or less angular, with the apical 

 end distended, and the cavity containing a laige number of 

 seeds. 



The author thinks that— looking at the matter from the 

 commercial point of view — the form of papaw flower with 

 small,, slender ovaries is to be ]ireferred, since it yields a fruit 

 that is more easily packed. Under the usual methods of 

 propagation, a large production of seedlings is not considered 

 profitable, and an attempt to originate a di.stinct variety of 

 papaw would probably necessitate hand pollination, iidaeed- 

 ing, and rigid selection for .several generations. 



CHINESE VEGETABLE TALLOW. 



An interesting tree, which is native to China and 

 Japan, but which, has been introduced into many other 

 parts of the world, as India, Cochin-China, South 

 Carolina, the Soudan, etc., is Sa.'piuim sehiferuni. It 

 will be remembered that one or two species of the 

 Sapium genus are indigenous to British Cuiana, Trini- 

 dad, etc., (e.g. S. Jcnma ni, S. ancwparluin), nud ure 

 valuable on •account of their rubber-yielding properties. 

 >S'. sehlfi'rum also has an economic value, this being 

 due to the fatty matter surrounding the seeds, whicii 

 is utilized for a number of purposes. The following 

 interesting information is taken from an article whicli 

 appeared in a former number of the Indian Af/ri- 

 cultii.rul Ledger: — 



The Chine.se tallow tree is from 2-t to .30 feet high, 

 with a whitish-grey bark. The tree is ornamental in 

 appearance ; the leaves are dark-green, which redden before 

 they fall. Flowers are borne in red terminal spikes, and 

 .seeds are produced about Novend^er and December. 

 S. sehifnrum is readily propagated by cuttings, and is 

 cultivated on a large scale in China, where the leaves are 

 reijorted to be used in the preparation of a black dye. 



The fatty or wa.vy matter obtained from the layer 

 surrounding the seeds of S. seliiU'ruin is used in China in 

 place of arumal tallow for the manufacture of candles, soap, 

 and in cloth-dre.s.sing. The candles made from this vegetable 

 fat with a small admixture of insect wax are reported to be 

 white in colour, and to burn with a clear, inodorous Hame, 



without smoke. : This vegetable tallow melts at a temjiera- 

 ture of about -lO'C. It is hard, brittle, and almost colourles.s, 

 and does not leave a grease s[)ot on paper. 



In addition to the solid fat surrounding the seed.s, 

 a brownish-yellow oil is obtained from the endosperm or ker- 

 nel, which is used as a bnrniiig^ oil, and also in the [u-eparation 

 of varnishes, on account of its drying properties. This oil is 

 extracted liy heating after the outside tallow has been 

 leinoved ; it is light and strong-smelling, and turns a yellow- 

 ish colour on standing. 



The mixture of the two fats — the outside tallow and 

 the oil from the kernel— has a melting pi^int of from 2G" to 

 ■32" C, and is stated to be a good substitute for lard for 

 industrial purposes. 



Vegetable tallow is exported from China in hard, white 

 cake.=, weighing about 1 cwt. These shipments have sh<iwu 

 a large increase of late years, having advanced from -18,73-5 

 picnls [1 picul = 1.33:, lb.] in 1905, to 127,296 piculs (valued 

 at £187,220) in 1907. Of this latter (piantity, about half 

 went to the United Kingdom. 



It may be addixl that the vegetable tallow tree 

 has been introduced into Cuba, Porto Rico, and 

 Martinique, and numerous specimens are to be seen in 

 those islands. It is hoped to obtain cuttings or seed.s 

 of this interesting tree for propagation in the Botanic 

 Gardens of the British West Indies. 



TAPPING PARA RUBBER TREES. 



Considerable ditierenee of opinion still exists as ta 

 the most suitable method b^' which the tapping of 

 Hevea rubber trees should be regulated. What is 

 required, of course, is a simple and practical method 

 which will reduce to a minimum the time required for 

 recover}- of the tree, and at the same time assure 

 a large yield and low cost of manipulation. 



This matter was discussed some time ago in the 

 Jdii riad d'Ai/rirul/urc Tnipicale, where the o])inions 

 of different authorities on the subject were quoted. 



Mr. J. C. ^V'illis, of Ceylon, states that tapjiing should not 

 take place until the tree measures 18 inches in girth at 3 feet 

 from the ground, and should then only be done lightly. 

 ;Mr. Herbert Wright, however, would have the minimum 

 circumference at the time of tapping, to be 2 feet or morei 



^■arious observations have been made also as to the time 

 for the full recovery of the bark after tapping. This is 

 placed at from two to four years by different authorities. 

 Tapping every other day is generally regarded as being better 

 than daily tapping. No definite conclusions appear to have 

 been arrived at as to the possible advantages of allowing still 

 longer intervals to elapse between tappings. There is need of 

 exiieriment work also to settle the question, as to whether the 

 frequency of tapping would liest be varied in the wet and dry' 

 seasons respectively, or shoulil take place at regular intervals 

 throughout. 



The different systems under which the cuts are made 

 for drawing off the latex (herring-bone, half-.spiral, spiral, and 

 V cuts, etc.) are described. It does not appear that anj' 

 decision is arrived at with regard to the respective merits of 

 these different methods, but it is pointed out that the full 

 spiral is most likely to affect the vitality of the trees. 



In all cases of tapping for rubber, the [loint to be 

 guarded against is damage loitlie cambium. This is far more 

 prenfdicial to the trees than the mere removal of later. 



