Vol. XI. No. 263. 



THE AGRICULTURAL NEWS. 



If" A 



STUDENTS' CORNER. 



.JUNE. 



FiiisT Period. 

 Seasonal Notes. 



It i.s a well-recognized fact that no two living beings, 

 whether they are plants or animals, are exactly alike. The 

 phenomenon is known as variation, and its existence enables 

 the agriculturist and the horticulturist, as well as the stock 

 breeder, to obtain superior kinds of the living beings in which 

 he is interested. In nature, the eti'ect of the existence of 

 variation is that the weaker forms, or those less suitable for 

 continued existence under the conditions, disappear, and only 

 the varieties that are most fitted to exist under the circum- 

 stances are permitted to survive and reproduce their species. 

 One of the mo.st powerful causes of this kind of selection is 

 competition. In the case of plants, many more seeds of any 

 given sort are produced in each .■reason than are required for 

 the number of plants for which food is available, so that the 

 matter is important in its effect in preventing the numbers of 

 any one kind of plant from increa.«ing to a disproportionate 

 extent. 



Sometimes, variations takes place to such a degree that 

 the new plant is completely difterent in one or more respects 

 from those which produced it. This variation is called muta- 

 tion. It may happen that the new characteristic makes the 

 form particularly valuable to mankind, but its utility is often 

 small because the plant possessing it is incapable of transmit- 

 ting the special property to its offspring: the latter are, in 

 fact, most likely (as it is expressed) to revert to the former 

 type. There is also the chance that the new form may not 

 be adapted to its surroundings, and it will then be quickly 

 extinguished. On the other hand, the product of mutation — 

 the 'sport' as it is termed — may be better suited to its envir- 

 onment than the kind of I'lant from which it came, and it 

 may in addition be able to produce offspring possessing its 

 special characters. In this case, mutation has given rise to 

 a plant that may prove to be of great utility. 



The name 'natural selection' is given to the way in which 

 new kinds of plants are produced by these means, in nature. 

 The common weeds have their origin in this manner, and it 

 is their very fitness to survive, under the conditions in which 

 they are found, that makes them so difficult to eradicate. 

 Further, the varieties or races of plants that are only suited 

 to a limited condition of tenqierature, climate or soil, have 

 been produced in this way. This natural adaption to defi- 

 nite climatic conitions should be considered carefully when 

 it is desired to effect the introduction of some certain variety 

 of a plant. 



The chief imiiortance of these matters to the agricul- 

 turi.st is that man is enabled to perform artificial selection, 

 and thus to obtain kinds of plants that are more prolific, or 

 more definitely suited to his needs, in a much smaller time 

 than this can be done in nature. 



Give examples that have come within your knowledge, 

 of plants that are being improved or maintained in a con- 

 dition of superiority to the common forma, by means of 

 artificial selection. State what other means exist for the 

 improvement of plants. 



Questions for Candidates. 



Preliminary Questions. 

 (1) Give an account of six plants that are commonly 

 -classed as weeds. 



(2) How do plants give evidence of injury to ihoir 

 roots? 



(3) What is the difference Vietween parasitic and 

 saprophytic fungi? 



Intermediate Questions. 



(1) Write an account of the special characteristics hy 

 means of which any weeds with which you are acquainted are 

 enabled to persist. 



(2) '\Vhy is care required to prevent injury to the roots 

 of plants; ilention any particular case. 



(3) Describe the life-hi.story of any saprophytic fungus 

 that you have studied. 



Final Que.stions. 



{I) Give an account of any uses of weeds on an estatt;. 

 In what indirect ways are weeds of use to the agriculturists 



(2) Provide a description of any root disease of plants 

 which you have observed, giving careful attention to ita 

 symptoms. 



(3) State the usefulness, in any respects, of fungi tu 

 mankind. 



AGRICULTURAL PROGRESS IN DOMINICA. 



The address liy His }Ionour the Administrator, delivered 

 at a meeting of the Legislative ( 'ouncil, 1 )ominica, held on 

 March 21, 1912, gives a review of the official returns of the 

 Presidency, which shows that steady progress continues to be 

 made in the trade and agriculture of the island. A review 

 of the address, as regards matters more specially connected 

 with agriculture, follows here. 



During the year 1911, the total trade of the island, 

 excluding the value of whale oil and stores shipped in transit, 

 reached the value of £224,793; the annual average for iha 

 five previous years was £221,687. A consideration of iha 

 figures has shown that there has been an increase of 68 per 

 cent, in the trade of Dominica during the past ten years. The 

 exports during 1911 amounted in value to £100,70-5, in which 

 were limes, value £72,929, and cacao, value £21,702. On 

 the basis of the export returns, the lime crop for 1911 

 amounted to 3.")-j,000 barrels; this is less by some 14,000 

 barrels than the unprecedented crop of 1910, but it is pro- 

 bable that this smaller amount is only apparent, as some 

 quantity of the lime products of 1911 was held over for ship- 

 ment during the present year. It may be stated shortly tha,t 

 the conditions concerning the lime irop indicate a satisfactory 

 expansion in the lime industry. 



The exports of cacao during 1911 were 10,053 cwt.; this 

 is less by about 1,200 cwt. than the exports of the previous 

 year. The cacao crop has remained somewhat stationary for 

 some years past, and the reason adduced for this by the Cura- 

 tor of the Botanic Station is that more attention is being 

 paid to lime cultivation, and that on the death of cacao trees 

 they are replaced bj' limes in preference to fresh cacao plants. 

 Reference is made to the excellent report received recent- 

 ly from the Imperial Institute concerning rubber from Dom- 

 inica. A note on this was given in thi^ volume of the 

 Agricultural News, p. 121. 



Among the other matters considered in the address, the 

 reference to the work on the Imperial road is of most direct 

 agricultural import. In relation to this it is stated that the 

 work of improving and metalling the first 8 miles of the road, 

 for which a vote of £-500 has been made during the last 

 financial year, is in hand, and that a revote of £2U(> out o£ 

 this sum will be asked for, as this was the estimated unex- 

 pended balance of the vote remaining on March 31, 19IiL 



