228 



THE AGRICULTURAL NEWS. 



July 24. 1909. 



— - ^'7 ^^ r^T^^ ^ST-^^ 



WEST INDIAN FRUIT. 



THE NORMAL AND ABNORMAL 



SEEDLINGS OF THE MANGO. 



In connexion with the article on ' The production 

 of more than one Seedling from a Single Seed of the 

 Orange and Maugo', published in the current volume 

 of the Afjr-iculturul Neivs on p. l.S7, the following 

 remarks may be of interest. 



In the article referred to it was shown that the 

 abnormal seedlings were of the nature of vegetative 

 buds formed from the nucellus of the seed, and conse- 

 quently, would breed true to the parent plant, while 

 the normal seedling was the product of cross-fertiliza- 

 tion and could not therefore be expected to come true. 



ilr. Jones, Curator of the Botanic Station, Doniiniea, 

 Las furnished the following interesting information in con- 

 nexion with this point. He says : — 



' I have raised a large number of mango .«eedlings for 

 stocks at various times, and I have noticed that the majority 

 of varieties in Dominica are normal. Occasionally adventi- 

 tious seedlings are formed. 



' One point in connexion with this is wnith noting. 

 When several seedlings are produced from one seed, one 

 seedling, evidently the normal one, is stronger than the rest. 

 It has u.snally twice the size and much greater vigour than 

 the others, which are probably adventitious. Should this 

 prove correct, it means that the adventitious seedling.s which 

 may probaljly breed true, can be selected ^vhen in the seed 

 beds. This would be very important. It also explains why 

 there is hardly a case on record where good varieties, which 

 produce both normal and adventitious embryos, breed true ; 

 for it is certain that the weak seedlings, probably adventi- 

 tious, are discarded for the strong seedlings, probably normab. 



This point should be tested by growing the weak seed- 

 lings ol such varieties until they bear fruit, when it can be 

 seen whether they have come true to the original stock or not. 

 The same could be done with the strong seedlings which 

 would not be exiiected to breed true. 



In order to shorten the time necessary fur tlu'se experi- 

 ments, the following method, for inducing the trees to bear 

 while still very young, might be adopted. This suggestion 

 is also due to Mr. Jones. He finds that the shock caused 

 by grafting and heading liack will in some cases cause the 

 stock to bear fruit when only twenty months old. OtJiersliave 

 found that twistuig the tojj of the stem or damaging it in 

 any similar way will also produce the same result. In 

 this wav the seedlings niav he tested while still very voung. 



Mr. Jones further suggests that 'it would be of 

 interest to know if varieties such as Pere Louis and No. 11, 

 which breed true, produce adventitious seedlings in clusters 

 of equal strength, the strong normal seedling being absent'. 

 These seedlings might also be tested to determine if they 

 were all adventitious, or if a normal seedling is really present 

 though exactly resembling the others. 



Should it prove to be the case that no normal seedlin" 

 is present, it would point to the fact that in such varieties' 

 which breed true, normal fertilization does not take place', 

 and consequently, all the emliryos are formed by buddin" 

 from the nucellus. ^ 



In the mango, the increase in size of the fruit is attended 

 hy a decrease in size of the stone, and consequently of the 

 reserve food material that the embryo has to draw on. This 

 suggests that the better varieties with larger fruits are less 

 likely to produce adventitious embryos than those with 

 poorer fruits. This point, al.so, might easily be investigated, 

 and the results would prove of interest as indicating whether 

 attempts to grow improved varieties from seed were likely 

 to meet with success or not. 



TBE OIL ENGINE FOR LIME-CRUSHING 

 MILLS. 



The following information on the advantages of 

 the oil engine iu producing puwer for lime-crushino- is 

 obtained from notes which were received from Mr.°G. 

 Downing, Lisdara, Dominic i, through the Curator of 

 the Botanic Station in that Island. ' These advantao-es 

 are stated to arise both in the simplicity of the structure 

 ami working of the engine itself, and "in the matter of 

 the attention and fuel reipiired for that purpose, as the 

 following excerpts from the notes show : — 



The construction tff the engine (a -o-horse power horizontal 

 Horiuhy) is simple ; it is not likely to get out of order ; it 

 is compact, and is ecoinomical to work, bm-ning, as it does, 

 a low grade rock oil. The fuel consumption is very .small- 

 it nuikes little noise ;" is easily handled, and, once started,' 

 requires little or no looking after, for the oil is automatically 

 fed into the vaporizer by the engine itself when running. 

 When_ starting, it t^kos about ten minutes to heat tluj 

 vaporizer, and then the engine is ready for use. 



The engine economizes space, time, labour, and trouble ; 

 its price is reasonable, and the workmanship excellent. 



As is pointed out, such an engine should bo 

 specially useful in places where the supply of water is 

 limited. 



